Patent Publication Number: US-9414838-B2

Title: Tissue thickness compensator comprised of a plurality of materials

Description:
BACKGROUND 
     The present invention relates to surgical instruments and, in various embodiments, to surgical cutting and stapling instruments and staple cartridges therefor that are designed to cut and staple tissue. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a cross-sectional view of a surgical instrument embodiment; 
         FIG. 1A  is a perspective view of one embodiment of an implantable staple cartridge; 
         FIGS. 1B-1E  illustrate portions of an end effector clamping and stapling tissue with an implantable staple cartridge; 
         FIG. 2  is a partial cross-sectional side view of another end effector coupled to a portion of a surgical instrument with the end effector supporting a surgical staple cartridge and with the anvil thereof in an open position; 
         FIG. 3  is another partial cross-sectional side view of the end effector of  FIG. 2  in a closed position; 
         FIG. 4  is another partial cross-sectional side view of the end effector of  FIGS. 2 and 3  as the knife bar is starting to advance through the end effector; 
         FIG. 5  is another partial cross-sectional side view of the end effector of  FIGS. 2-4  with the knife bar partially advanced therethrough; 
         FIGS. 6A-6D  diagram the deformation of a surgical staple positioned within a collapsible staple cartridge body in accordance with at least one embodiment; 
         FIG. 7A  is a diagram illustrating a staple positioned in a crushable staple cartridge body; 
         FIG. 7B  is a diagram illustrating the crushable staple cartridge body of  FIG. 7A  being crushed by an anvil; 
         FIG. 7C  is a diagram illustrating the crushable staple cartridge body of  FIG. 7A  being further crushed by the anvil; 
         FIG. 7D  is a diagram illustrating the staple of  FIG. 7A  in a fully formed configuration and the crushable staple cartridge of  FIG. 7A  in a fully crushed condition; 
         FIG. 8  is a top view of a staple cartridge in accordance with at least one embodiment comprising staples embedded in a collapsible staple cartridge body; 
         FIG. 9  is an elevational view of the staple cartridge of  FIG. 8 ; 
         FIG. 10  is an exploded perspective view of an alternative embodiment of a compressible staple cartridge comprising staples therein and a system for driving the staples against an anvil; 
         FIG. 10A  is a partial cut-away view of an alternative embodiment of the staple cartridge of  FIG. 10 ; 
         FIG. 11  is a cross-sectional view of the staple cartridge of  FIG. 10 ; 
         FIG. 12  is an elevational view of a sled configured to traverse the staple cartridge of  FIG. 10  and move the staples to toward the anvil; 
         FIG. 13  is a diagram of a staple driver which can be lifted toward the anvil by the sled of  FIG. 12 ; 
         FIG. 14  is a perspective view of a staple cartridge comprising a rigid support portion and a compressible tissue thickness compensator for use with a surgical stapling instrument in accordance with at least one embodiment of the invention; 
         FIG. 15  is a partially exploded view of the staple cartridge of  FIG. 14 ; 
         FIG. 16  is a fully exploded view of the staple cartridge of  FIG. 14 ; 
         FIG. 17  is another exploded view of the staple cartridge of  FIG. 14  without a warp covering the tissue thickness compensator; 
         FIG. 18  is a perspective view of a cartridge body, or support portion, of the staple cartridge of  FIG. 14 ; 
         FIG. 19  is a top perspective view of a sled movable within the staple cartridge of  FIG. 14  to deploy staples from the staple cartridge; 
         FIG. 20  is a bottom perspective view of the sled of  FIG. 19 ; 
         FIG. 21  is an elevational view of the sled of  FIG. 19 ; 
         FIG. 22  is a top perspective view of a driver configured to support one or more staples and to be lifted upwardly by the sled of  FIG. 19  to eject the staples from the staple cartridge; 
         FIG. 23  is a bottom perspective view of the driver of  FIG. 22 ; 
         FIG. 24  is a wrap configured to at least partially surround a compressible tissue thickness compensator of a staple cartridge; 
         FIG. 25  is a partial cut away view of a staple cartridge comprising a rigid support portion and a compressible tissue thickness compensator illustrated with staples being moved from an unfired position to a fired position during a first sequence; 
         FIG. 26  is an elevational view of the staple cartridge of  FIG. 25 ; 
         FIG. 27  is a detail elevational view of the staple cartridge of  FIG. 25 ; 
         FIG. 28  is a cross-sectional end view of the staple cartridge of  FIG. 25 ; 
         FIG. 29  is a bottom view of the staple cartridge of  FIG. 25 ; 
         FIG. 30  is a detail bottom view of the staple cartridge of  FIG. 25 ; 
         FIG. 31  is a longitudinal cross-sectional view of an anvil in a closed position and a staple cartridge comprising a rigid support portion and a compressible tissue thickness compensator illustrated with staples being moved from an unfired position to a fired position during a first sequence; 
         FIG. 32  is another cross-sectional view of the anvil and the staple cartridge of  FIG. 31  illustrating the anvil in an open position after the firing sequence has been completed; 
         FIG. 33  is a partial detail view of the staple cartridge of  FIG. 31  illustrating the staples in an unfired position; 
         FIG. 34  is a cross-sectional elevational view of a staple cartridge comprising a rigid support portion and a compressible tissue thickness compensator illustrating the staples in an unfired position; 
         FIG. 35  is a detail view of the staple cartridge of  FIG. 34 ; 
         FIG. 36  is an elevational view of an anvil in an open position and a staple cartridge comprising a rigid support portion and a compressible tissue thickness compensator illustrating the staples in an unfired position; 
         FIG. 37  is an elevational view of an anvil in a closed position and a staple cartridge comprising a rigid support portion and a compressible tissue thickness compensator illustrating the staples in an unfired position and tissue captured between the anvil and the tissue thickness compensator; 
         FIG. 38  is a detail view of the anvil and staple cartridge of  FIG. 37 ; 
         FIG. 39  is an elevational view of an anvil in a closed position and a staple cartridge comprising a rigid support portion and a compressible tissue thickness compensator illustrating the staples in an unfired position illustrating thicker tissue positioned between the anvil and the staple cartridge; 
         FIG. 40  is a detail view of the anvil and staple cartridge of  FIG. 39 ; 
         FIG. 41  is an elevational view of the anvil and staple cartridge of  FIG. 39  illustrating tissue having different thicknesses positioned between the anvil and the staple cartridge; 
         FIG. 42  is a detail view of the anvil and staple cartridge of  FIG. 39  as illustrated in  FIG. 41 ; 
         FIG. 43  is a diagram illustrating a tissue thickness compensator which is compensating for different tissue thickness captured within different staples; 
         FIG. 44  is a diagram illustrating a tissue thickness compensator applying a compressive pressure to one or more vessels that have been transected by a staple line; 
         FIG. 45  is a diagram illustrating a circumstance wherein one or more staples have been improperly formed; 
         FIG. 46  is a diagram illustrating a tissue thickness compensator which could compensate for improperly formed staples; 
         FIG. 47  is a diagram illustrating a tissue thickness compensator positioned in a region of tissue in which multiple staples lines have intersected; 
         FIG. 48  is a diagram illustrating tissue captured within a staple; 
         FIG. 49  is a diagram illustrating tissue and a tissue thickness compensator captured within a staple; 
         FIG. 50  is a diagram illustrating tissue captured within a staple; 
         FIG. 51  is a diagram illustrating thick tissue and a tissue thickness compensator captured within a staple; 
         FIG. 52  is a diagram illustrating thin tissue and a tissue thickness compensator captured within a staple; 
         FIG. 53  is a diagram illustrating tissue having an intermediate thickness and a tissue thickness compensator captured within a staple; 
         FIG. 54  is a diagram illustrating tissue having another intermediate thickness and a tissue thickness compensator captured within a staple; 
         FIG. 55  is a diagram illustrating thick tissue and a tissue thickness compensator captured within a staple; 
         FIG. 56  is a partial cross-sectional view of an end effector of a surgical stapling instrument illustrating a firing bar and staple-firing sled in a retracted, unfired position; 
         FIG. 57  is another partial cross-sectional view of the end effector of  FIG. 56  illustrating the firing bar and the staple-firing sled in a partially advanced position; 
         FIG. 58  is a cross-sectional view of the end effector of  FIG. 56  illustrating the firing bar in a fully advanced, or fired, position; 
         FIG. 59  is a cross-sectional view of the end effector of  FIG. 56  illustrating the firing bar in a retracted position after being fired and the staple-firing sled left in its fully fired position; 
         FIG. 60  is a detail view of the firing bar in the retracted position of  FIG. 59 ; 
         FIG. 61  is a cross-sectional perspective view of an embodiment of a cutting blade being advanced distally within an end effector of a surgical instrument to incise tissue; 
         FIG. 62  is a cross-sectional side view illustrating features on the cutting blade of  FIG. 61  configured to direct a substance within a tissue thickness compensator toward the tissue; 
         FIG. 63  is a cross-sectional perspective view of an alternative embodiment of a cutting blade being advanced distally within an end effector of a surgical instrument to incise tissue; 
         FIG. 64  is a cross-sectional perspective view of another alternative embodiment of a cutting blade being advanced distally within an end effector of a surgical instrument to incise tissue; 
         FIG. 65  is a cross-sectional side view illustrating features on the cutting blade of  FIG. 64  configured to mix a substance within a first tissue thickness compensator with a substance from a second tissue thickness compensator; 
         FIG. 66  is a front view illustrating features on the cutting blade of  FIG. 64  configured to mix a substance within a first tissue thickness compensator with a substance from a second tissue thickness compensator; 
         FIG. 67  is a cross-sectional top view illustrating features on the cutting blade of  FIG. 64  configured to mix a substance within a first tissue thickness compensator with a substance from a second tissue thickness compensator; 
         FIG. 68  is a cross-sectional perspective view of another alternative embodiment of a cutting blade being advanced distally within an end effector of a surgical instrument to incise tissue; 
         FIG. 69  is a cross-sectional side view illustrating features on the cutting blade of  FIG. 68  configured to spread a substance contained within a tissue thickness compensator; and 
         FIG. 70  is a cross-sectional side view of the cutting blade of  FIG. 68  spreading the substance. 
         FIG. 71  is partial cut-away perspective view of a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 72  illustrates a medicament being loaded into a tissue thickness compensator; 
         FIG. 73  is a cross-sectional end view of a tube positioned within the tissue thickness compensator of  FIG. 71  comprising a medicament contained therein; 
         FIG. 74  illustrates the tissue thickness compensator of  FIG. 71  being positioned and compressed against a patient&#39;s tissue; 
         FIG. 75  is a cross-sectional end view of an end effector of a surgical stapling instrument illustrating staples being fired through the tissue thickness compensator of  FIG. 71 ; 
         FIG. 76  is a graph depicting the dissolution of a capsule contained within a tissue thickness compensator, wherein the capsule comprises a plurality of medicament layers; 
         FIG. 77  illustrates a first, or outer, layer of the capsule of  FIG. 76  being dissolved; 
         FIG. 78  illustrates a second layer of the capsule of  FIG. 76  being dissolved; 
         FIG. 79  illustrates a third layer of the capsule of  FIG. 76  being dissolved; 
         FIG. 80  illustrates a fourth, or inner, layer of the capsule of  FIG. 76  being dissolved; 
         FIG. 81  is a partial cut-away view of a staple cartridge in accordance with at least one embodiment comprising a tissue thickness compensator including a plurality of vertical capsules; 
         FIG. 82  is a perspective view of a vertical capsule of  FIG. 81 ; 
         FIG. 83  is a partial cut-away view of the staple cartridge of  FIG. 81  illustrating staples contained therein in an unfired position; 
         FIG. 84  is a cross-sectional side view of the staple cartridge of  FIG. 81  illustrating the staples of  FIG. 83  being moved from an unfired position to a fired position; 
         FIG. 85  is a partial cut-away view of a tissue thickness compensator comprising vertical capsules positioned therein in accordance with at least one embodiment; 
         FIG. 86  is a partial cut-away view of a tissue thickness compensator comprising a plurality of capsules having openings defined therein; 
         FIG. 87  is a cross-sectional end view of an end effector of a surgical stapling instrument comprising a plurality of staples in an unfired position and a plurality of piercing members configured to rupture capsules or tubes contained within a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 88  is an elevational view of a staple of  FIG. 87  in an unfired configuration; 
         FIG. 89  is an elevational view of the staple of  FIG. 88  in a fired configuration; 
         FIG. 90  is an elevational view of a piercing member of  FIG. 87 ; 
         FIG. 91  is a cross-sectional end view of the end effector of  FIG. 87  illustrating the staples and the piercing members in a fired position; 
         FIG. 92  is a cross-sectional side view of the end effector of  FIG. 87  illustrating the staples and the piercing members being moved from an unfired position to a fired position; 
         FIG. 93  is a top cut-away view of a staple cartridge in accordance with at least one embodiment including a tissue thickness compensator comprising a plurality of capsules positioned therein; 
         FIG. 94  is a detail view of the staple cartridge of  FIG. 93 ; 
         FIG. 95  is a cross-sectional end view of the staple cartridge of  FIG. 93  positioned within an end effector illustrating staples contained within the staple cartridge in a fired position; 
         FIG. 96  is a cross-sectional end view of the staple cartridge of  FIG. 93  in the end effector of  FIG. 95  illustrating a cutting member being advanced through the capsules in the tissue thickness compensator; 
         FIG. 97  is a perspective view of a tissue thickness compensator comprising a longitudinal member in accordance with at least one embodiment; 
         FIG. 98  is a cross-sectional view of a mold configured to produce the tissue thickness compensator of  FIG. 97 ; 
         FIG. 99  is a cross-sectional end view of the mold of  FIG. 98  illustrating the longitudinal member of  FIG. 97  positioned therein; 
         FIG. 100  is a cross-sectional end view of the mold of  FIG. 98  illustrating tissue thickness compensator material being poured into the mold of  FIG. 98 ; 
         FIG. 101  is a cut-away perspective view of a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 102  is a perspective view of a support member configured to be embedded in a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 103  is a cut-away perspective view of a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 104  is a cross-sectional end view illustrating a mold for manufacturing the tissue thickness compensator of  FIG. 103 ; 
         FIG. 105  is a cross-sectional view of the tissue thickness compensator of  FIG. 103 ; 
         FIG. 106  is a cross-sectional side view of the mold of  FIG. 104 ; 
         FIG. 107  is a cross-sectional end view of a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 108  is a cross-sectional end view of another tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 109  is a detail view of a scaffold material for a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 110  is a detail view of a tissue thickness compensator in an unexpanded state in accordance with at least one embodiment; 
         FIG. 111  is a detail view of the tissue thickness compensator of  FIG. 110  in an expanded state; 
         FIG. 112  is a cut-away perspective view of a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 113  is a partial cut-away perspective view of a tissue thickness compensator being manufactured in a mold in accordance with at least one embodiment; 
         FIG. 114  is a cross-sectional perspective view of a tissue thickness compensator in accordance with at least one alternative embodiment; 
         FIG. 115  is a cross-sectional end view of a tissue thickness compensator in accordance with at least one alternative embodiment; 
         FIG. 116  is a partial perspective view of a tissue thickness compensator in accordance with at least one alternative embodiment; 
         FIG. 117  is an elevational view of an end effector of a surgical stapling instrument comprising a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 118  is an exploded view of the tissue thickness compensator of  FIG. 117  wherein the tissue thickness compensator comprises a plurality of layers; 
         FIG. 119  is a cross-sectional view of a layer of a tissue thickness compensator; 
         FIG. 120  is a cross-sectional view of another layer of a tissue thickness compensator; 
         FIG. 121  is a partial cross-sectional elevational view of the tissue thickness compensator of  FIG. 117  positioned between an anvil and a staple cartridge of the surgical stapling instrument; 
         FIG. 122  is another partial cross-sectional elevational view of the tissue thickness compensator of  FIG. 117  captured within a staple ejected from the staple cartridge and deformed by the anvil of the surgical stapling instrument; 
         FIG. 123  is another partial cross-sectional elevational view of the tissue thickness compensator of  FIG. 117  attached to tissue by the staple of  FIG. 122 ; 
         FIG. 124  is a perspective view of a layer of a tissue thickness compensator in accordance with at least one alternative embodiment; 
         FIG. 125  is a perspective view of an end effector of a surgical stapling instrument comprising a tissue thickness compensator including the layer of  FIG. 124 ; 
         FIG. 126  is a partial perspective view of a tissue thickness compensator in accordance with at least one alternative embodiment; 
         FIG. 127  is a perspective view of an end effector of a surgical stapling instrument comprising the tissue thickness compensator of  FIG. 126 ; 
         FIG. 128  is a perspective view of a plurality of coated fibers; 
         FIG. 129  is a perspective view illustrating an extrusion process for producing a coated fiber and/or a coated strand which can be dissected into coated fibers; 
         FIG. 130  is a cross-sectional perspective view of a coated fiber; 
         FIG. 131  is a perspective view illustrating a coating process utilizing a carrier fluid configured deposit a material on and/or within a fiber; 
         FIG. 132  is a perspective view of a staple cartridge including a tissue thickness compensator comprising the fibers of  FIG. 128 ; 
         FIG. 133  is a partial cut-away perspective view of a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 134  is a cross-sectional view of a medicament encased by a hydrophilic material in accordance with at least one embodiment; 
         FIG. 135  is a perspective view of the tissue thickness compensator of  FIG. 133  positioned within an end effector of a surgical instrument; 
         FIG. 136  is a partial cut-away perspective view of the medicament of  FIG. 134  being exposed to a liquid such that the medicament can weep out of the tissue thickness compensator of  FIG. 133 ; 
         FIG. 137  is a partial perspective view of a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 138  is a partial perspective view of the tissue thickness compensator of  FIG. 137  after it has been exposed to a liquid; 
         FIG. 139  is a perspective view of an end effector including the tissue thickness compensator of  FIG. 137  attached to an anvil; 
         FIG. 140  is a partial cut-away perspective view of a tissue thickness compensator comprising the medicament of  FIG. 134  and the fibers of  FIG. 128 ; 
         FIG. 141  is a partial perspective view of a staple cartridge comprising a tissue thickness compensator including a plurality of capsules; 
         FIG. 142  is a side view of the staple cartridge of  FIG. 141 ; 
         FIG. 143  illustrates the capsules of  FIG. 141  being placed in a mold; 
         FIG. 144  illustrates the capsules of  FIG. 141  settling to the bottom of the mold of  FIG. 143 ; 
         FIG. 145  illustrates a compensator body material being poured over the capsules of  FIG. 141 ; 
         FIG. 146  illustrates an embodiment in which the capsules of  FIG. 141  are denser than the compensator body material and remain on the bottom of the mold of  FIG. 143 ; 
         FIG. 147  illustrates an embodiment in which the capsules of  FIG. 141  are less dense than the compensator body material and can float to the top of the mold of  FIG. 143 ; 
         FIG. 148  illustrates an alternative embodiment of a mold including a plurality of recesses or dimples configured to receive the capsules of  FIG. 141 ; 
         FIG. 149  is a cross-sectional end view of an end effector of a surgical stapling instrument comprising a tissue thickness compensator positioned over a staple cartridge in accordance with at least one embodiment; 
         FIG. 150  is a cross-sectional end view of the end effector of  FIG. 149  illustrating staples fired from the staple cartridge and extending through the tissue thickness compensator of  FIG. 149 ; 
         FIG. 151  illustrates a mold and a plurality of medicament capsules positioned within the mold; 
         FIG. 152  is a cross-sectional end view of the mold illustrating a compensator body material being poured into the mold to form a tissue thickness compensator; 
         FIG. 153  is a perspective view of the tissue thickness compensator of  FIG. 152  attached to an anvil of a surgical stapling instrument; 
         FIG. 154  is a cross-sectional view of a mold configured to form the tissue thickness compensator of  FIG. 157  illustrating a first layer being poured into the mold; 
         FIG. 155  is a cross-sectional view of the mold of  FIG. 154  illustrating a capsule positioned on the first layer; 
         FIG. 156  is a cross-sectional view of the mold of  FIG. 154  illustrating a second layer being poured onto the capsule; 
         FIG. 157  is a perspective view of a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 158  is a perspective view of the tissue thickness compensator of  FIG. 157  positioned within an end effector of a surgical stapling instrument; 
         FIG. 159  is a perspective view of a compensator body of the tissue thickness compensator of  FIG. 162 ; 
         FIG. 160  is a perspective view of a longitudinal aperture defined in the compensator body of  FIG. 159 ; 
         FIG. 161  is a diagram illustrating a capsule being positioned within the longitudinal aperture of  FIG. 160 ; 
         FIG. 162  is a perspective view of an end effector of a surgical stapling instrument including a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 163  is a perspective view of a compensator body of the tissue thickness compensator of  FIG. 166 ; 
         FIG. 164  is a perspective view of a plurality of transverse apertures defined in the compensator body of  FIG. 163 ; 
         FIG. 165  is a diagram illustrating capsules being positioned within the transverse apertures of  FIG. 164 ; 
         FIG. 166  is a perspective view of an end effector of a surgical stapling instrument including a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 167  is a perspective view of a vertical mold configured to manufacture a tissue thickness compensator; 
         FIG. 168  is a perspective view of a capsule being positioned within the mold of  FIG. 167 ; 
         FIG. 169  is a perspective view of the capsule of  FIG. 168  positioned within the mold of  FIG. 167 ; 
         FIG. 170  is a perspective view of a cover placed against the mold of  FIG. 167  and a compensator body material being positioned within the mold; 
         FIG. 171  is a perspective view of the mold of  FIG. 167  illustrated with the cover of  FIG. 170  removed; 
         FIG. 172  illustrates a staple cartridge comprising a tissue thickness compensator and a tissue thickness compensator mat in accordance with at least one embodiment; 
         FIG. 173  is a partial bottom perspective view of the tissue thickness compensator mat of  FIG. 172 ; 
         FIG. 174  is a partial top perspective view of the tissue thickness compensator mat of  FIG. 172 ; 
         FIG. 175  is a partial cross-sectional view of the staple cartridge of  FIG. 172  being fired by a firing member, wherein the staple cartridge is illustrated without the tissue thickness compensator positioned thereon; 
         FIG. 176  is a top view of the tissue thickness compensator mat of  FIG. 172  being incised by a cutting member engaged with the firing member of  FIG. 175 , wherein the staple cartridge is illustrated without the tissue thickness compensator positioned thereon; 
         FIG. 177  is a top view of the tissue thickness compensator mat of  FIG. 172  being incised by a cutting member engaged with the firing member of  FIG. 175 , wherein the staple cartridge is illustrated with the tissue thickness compensator positioned thereon; 
         FIG. 178  is a plan view of a circular staple cartridge in accordance with at least one alternative embodiment comprising a circular tissue thickness compensator mat; 
         FIG. 179  illustrates a mold comprising a plurality of cavities configured to form tissue thickness compensators on a plurality of staple cartridge bodies simultaneously; 
         FIG. 180  illustrates staple cartridge bodies positioned within the cavities of  FIG. 179  and one or more sheets being placed over the cartridge bodies; 
         FIG. 181  illustrates the sheets of  FIG. 180  secured in place within the mold of  FIG. 179 ; 
         FIG. 182  illustrates an elongate tube member wound around a plurality of post supports within the mold of  FIG. 179 ; 
         FIG. 183  illustrates the sheets of  FIG. 180  secured in place over the staple cartridge bodies of  FIG. 179 ; 
         FIG. 184  illustrates the tube members of  FIG. 182  in position over the sheets of  FIG. 180 ; 
         FIG. 185  illustrates a compensator body material being poured into the mold of  FIG. 179 ; 
         FIG. 186  illustrates a cutting die positioned over the mold of  FIG. 179 ; 
         FIG. 187  illustrates the cutting die moved downwardly to cut the compensator body material of  FIG. 185  and the sheets of  FIG. 180 ; 
         FIG. 188  illustrates the cutting die moved upwardly away from the mold of  FIG. 179 ; 
         FIG. 189  is a cross-sectional end view of a tissue thickness compensator that is produced by the manufacturing process outlined in  FIGS. 179-188  in accordance with at least one embodiment; 
         FIG. 190  is a top view of a staple cartridge comprising a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 191  is a perspective view of the staple cartridge of  FIG. 190 ; 
         FIG. 192  is an illustration depicting the manufacture of the tissue thickness compensator of the staple cartridge of  FIG. 190 ; 
         FIG. 193  is an illustration of rollers flattening a tube of material to form a tissue thickness compensator in accordance with at least one embodiment; 
         FIG. 194  is an illustration of rollers forming a tissue thickness compensator in accordance with at least one alternative embodiment; 
         FIG. 195  is a partial perspective view of a staple cartridge including tissue thickness compensators produced by the process illustrated in  FIG. 194 ; 
         FIG. 196  is cross-sectional elevational view of staples being deployed from the staple cartridge of  FIG. 195 ; and 
         FIG. 197  is a cross-sectional end view of staples being deployed from the staple cartridge of  FIG. 195 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate certain embodiments of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION 
     The Applicant of the present application also owns the U.S. Patent Applications identified below which are each herein incorporated by reference in their respective entirety: 
     U.S. patent application Ser. No. 12/894,311, entitled SURGICAL INSTRUMENTS WITH RECONFIGURABLE SHAFT SEGMENTS, now U.S. Pat. No. 8,763,877; 
     U.S. patent application Ser. No. 12/894,340, entitled SURGICAL STAPLE CARTRIDGES SUPPORTING NON-LINEARLY ARRANGED STAPLES AND SURGICAL STAPLING INSTRUMENTS WITH COMMON STAPLE-FORMING POCKETS, now U.S. Pat. No. 8,899,463; 
     U.S. patent application Ser. No. 12/894,327, entitled JAW CLOSURE ARRANGEMENTS FOR SURGICAL INSTRUMENTS, now U.S. Pat. No. 8,978,956; 
     U.S. patent application Ser. No. 12/894,351, entitled SURGICAL CUTTING AND FASTENING INSTRUMENTS WITH SEPARATE AND DISTINCT FASTENER DEPLOYMENT AND TISSUE CUTTING SYSTEMS, now U.S. Pat. No. 9,113,864; 
     U.S. patent application Ser. No. 12/894,338, entitled IMPLANTABLE FASTENER CARTRIDGE HAVING A NON-UNIFORM ARRANGEMENT, now U.S. Pat. No. 8,864,007; 
     U.S. patent application Ser. No. 12/894,369, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING A SUPPORT RETAINER, now U.S. Patent Application Publication No. 2012/0080344; 
     U.S. patent application Ser. No. 12/894,312, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING MULTIPLE LAYERS, now U.S. Pat. No. 8,925,782; 
     U.S. patent application Ser. No. 12/894,377, entitled SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE, now U.S. Pat. No. 8,393,514; 
     U.S. patent application Ser. No. 12/894,339, entitled SURGICAL STAPLING INSTRUMENT WITH COMPACT ARTICULATION CONTROL ARRANGEMENT, now U.S. Pat. No. 8,840,003; 
     U.S. patent application Ser. No. 12/894,360, entitled SURGICAL STAPLING INSTRUMENT WITH A VARIABLE STAPLE FORMING SYSTEM, now U.S. Pat. No. 9,113,862; 
     U.S. patent application Ser. No. 12/894,322, entitled SURGICAL STAPLING INSTRUMENT WITH INTERCHANGEABLE STAPLE CARTRIDGE ARRANGEMENTS, now U.S. Pat. No. 8,740,034; 
     U.S. patent application Ser. No. 12/894,350, entitled SURGICAL STAPLE CARTRIDGES WITH DETACHABLE SUPPORT STRUCTURES AND SURGICAL STAPLING INSTRUMENTS WITH SYSTEMS FOR PREVENTING ACTUATION MOTIONS WHEN A CARTRIDGE IS NOT PRESENT, now U.S. Patent Application Publication No. 2012/0080478; 
     U.S. patent application Ser. No. 12/894,383, entitled IMPLANTABLE FASTENER CARTRIDGE COMPRISING BIOABSORBABLE LAYERS, now U.S. Pat. No. 8,752,699; 
     U.S. patent application Ser. No. 12/894,389, entitled COMPRESSIBLE FASTENER CARTRIDGE, now U.S. Pat. No. 8,740,037; 
     U.S. patent application Ser. No. 12/894,345, entitled FASTENERS SUPPORTED BY A FASTENER CARTRIDGE SUPPORT, now U.S. Pat. No. 8,783,542; 
     U.S. patent application Ser. No. 12/894,306, entitled COLLAPSIBLE FASTENER CARTRIDGE, now U.S. Pat. No. 9,044,227; 
     U.S. patent application Ser. No. 12/894,318, entitled FASTENER SYSTEM COMPRISING A PLURALITY OF CONNECTED RETENTION MATRIX ELEMENTS, now U.S. Pat. No. 8,814,024; 
     U.S. patent application Ser. No. 12/894,330, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX AND AN ALIGNMENT MATRIX, now U.S. Pat. No. 8,757,465; 
     U.S. patent application Ser. No. 12/894,361, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX, now U.S. Pat. No. 8,529,600; 
     U.S. patent application Ser. No. 12/894,367, entitled FASTENING INSTRUMENT FOR DEPLOYING A FASTENER SYSTEM COMPRISING A RETENTION MATRIX, now U.S. Pat. No. 9,033,203; 
     U.S. patent application Ser. No. 12/894,388, entitled FASTENER SYSTEM COMPRISING A RETENTION MATRIX AND A COVER, now U.S. Pat. No. 8,474,677; 
     U.S. patent application Ser. No. 12/894,376, entitled FASTENER SYSTEM COMPRISING A PLURALITY OF FASTENER CARTRIDGES, now U.S. Pat. No. 9,044,228; 
     U.S. patent application Ser. No. 13/097,865, entitled SURGICAL STAPLER ANVIL COMPRISING A PLURALITY OF FORMING POCKETS, now U.S. Patent Application Publication No. 2012/0080488; 
     U.S. patent application Ser. No. 13/097,936, entitled TISSUE THICKNESS COMPENSATOR FOR A SURGICAL STAPLER, now U.S. Pat. No. 8,657,176; 
     U.S. patent application Ser. No. 13/097,954, entitled STAPLE CARTRIDGE COMPRISING A VARIABLE THICKNESS COMPRESSIBLE PORTION, now U.S. Patent Application Publication No. 2012/0080340; 
     U.S. patent application Ser. No. 13/097,856, entitled STAPLE CARTRIDGE COMPRISING STAPLES POSITIONED WITHIN A COMPRESSIBLE PORTION THEREOF, now U.S. Patent Application Publication No. 2012/0080336; 
     U.S. patent application Ser. No. 13/097,928, entitled TISSUE THICKNESS COMPENSATOR COMPRISING DETACHABLE PORTIONS, now U.S. Pat. No. 8,746,535; 
     U.S. patent application Ser. No. 13/097,891, entitled TISSUE THICKNESS COMPENSATOR FOR A SURGICAL STAPLER COMPRISING AN ADJUSTABLE ANVIL, now U.S. Pat. No. 8,864,009; 
     U.S. patent application Ser. No. 13/097,948, entitled STAPLE CARTRIDGE COMPRISING AN ADJUSTABLE DISTAL PORTION, now U.S. Pat. No. 8,978,954; 
     U.S. patent application Ser. No. 13/097,907, entitled COMPRESSIBLE STAPLE CARTRIDGE ASSEMBLY, now U.S. Patent Application Publication No. 2012/0080338; 
     U.S. patent application Ser. No. 13/097,861, entitled TISSUE THICKNESS COMPENSATOR COMPRISING PORTIONS HAVING DIFFERENT PROPERTIES, now U.S. Pat. No. 9,113,865; 
     U.S. patent application Ser. No. 13/097,869, entitled STAPLE CARTRIDGE LOADING ASSEMBLY, now U.S. Pat. No. 8,857,694; 
     U.S. patent application Ser. No. 13/097,917, entitled COMPRESSIBLE STAPLE CARTRIDGE COMPRISING ALIGNMENT MEMBERS, now U.S. Pat. No. 8,777,004; 
     U.S. patent application Ser. No. 13/097,873, entitled STAPLE CARTRIDGE COMPRISING A RELEASABLE PORTION, now U.S. Pat. No. 8,740,038; 
     U.S. patent application Ser. No. 13/097,938, entitled STAPLE CARTRIDGE COMPRISING COMPRESSIBLE DISTORTION RESISTANT COMPONENTS, now U.S. Pat. No. 9,016,542; 
     U.S. patent application Ser. No. 13/097,924, entitled STAPLE CARTRIDGE COMPRISING A TISSUE THICKNESS COMPENSATOR, now U.S. Pat. No. 9,168,038;
     U.S. patent application Ser. No. 13/242,029, entitled SURGICAL STAPLER WITH FLOATING ANVIL, now U.S. Pat. No. 8,893,949;   

     U.S. patent application Ser. No. 13/242,066, entitled CURVED END EFFECTOR FOR A STAPLING INSTRUMENT, now U.S. Patent Application Publication No. 2012/0080498; 
     U.S. patent application Ser. No. 13/242,086, entitled STAPLE CARTRIDGE INCLUDING COLLAPSIBLE DECK, now U.S. Pat. No. 9,055,941; 
     U.S. patent application Ser. No. 13/241,912, entitled STAPLE CARTRIDGE INCLUDING COLLAPSIBLE DECK ARRANGEMENT, now U.S. Pat. No. 9,050,084; 
     U.S. patent application Ser. No. 13/241,922, entitled SURGICAL STAPLER WITH STATIONARY STAPLE DRIVERS, now U.S. Pat. No. 9,216,019; 
     U.S. patent application Ser. No. 13/241,637, entitled SURGICAL INSTRUMENT WITH TRIGGER ASSEMBLY FOR GENERATING MULTIPLE ACTUATION MOTIONS, now U.S. Pat. No. 8,789,741; and 
     U.S. patent application Ser. No. 13/241,629, entitled SURGICAL INSTRUMENT WITH SELECTIVELY ARTICULATABLE END EFFECTOR, now U.S. Patent Application Publication No. 2012/0074200. 
     The Applicant of the present application also owns the U.S. Patent Applications identified below which were filed on Mar. 28, 2012 and which are each herein incorporated by reference in their respective entirety: 
     U.S. patent application Ser. No. 13/433,096, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF CAPSULES, now U.S. Patent Application Publication No. 2012/0241496; 
     U.S. patent application Ser. No. 13/433,103, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF LAYERS, now U.S. Patent Application Publication No. 2012/0241498; 
     U.S. patent application Ser. No. 13/433,098, entitled EXPANDABLE TISSUE THICKNESS COMPENSATOR, now U.S. Patent Application Publication No. 2012/0241491; 
     U.S. patent application Ser. No. 13/433,102, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A RESERVOIR, now U.S. Pat. No. 9,232,241; 
     U.S. patent application Ser. No. 13/433,114, entitled RETAINER ASSEMBLY INCLUDING A TISSUE THICKNESS COMPENSATOR, now U.S. Patent Application Publication No. 2012/0241499; 
     U.S. patent application Ser. No. 13/433,136, entitled TISSUE THICKNESS COMPENSATOR COMPRISING AT LEAST ONE MEDICAMENT, now U.S. Patent Application Publication No. 2012/0241492; 
     U.S. patent application Ser. No. 13/433,141, entitled TISSUE THICKNESS COMPENSATOR COMPRISING CONTROLLED RELEASE AND EXPANSION, now U.S. Patent Application Publication No. 2012/0241493; 
     U.S. patent application Ser. No. 13/433,144, entitled TISSUE THICKNESS COMPENSATOR COMPRISING FIBERS TO PRODUCE A RESILIENT LOAD, now U.S. Pat. No. 9,277,919; 
     U.S. patent application Ser. No. 13/433,148, entitled TISSUE THICKNESS COMPENSATOR COMPRISING STRUCTURE TO PRODUCE A RESILIENT LOAD, now U.S. Pat. No. 9,220,500; 
     U.S. patent application Ser. No. 13/433,155, entitled TISSUE THICKNESS COMPENSATOR COMPRISING RESILIENT MEMBERS, now U.S. Patent Application Publication No. 2012/0241502; 
     U.S. patent application Ser. No. 13/433,163, entitled METHODS FOR FORMING TISSUE THICKNESS COMPENSATOR ARRANGEMENTS FOR SURGICAL STAPLERS, now U.S. Patent Application Publication No. 2012/0248169; 
     U.S. patent application Ser. No. 13/433,167, entitled TISSUE THICKNESS COMPENSATORS, now U.S. Pat. No. 9,220,501; 
     U.S. patent application Ser. No. 13/433,175, entitled LAYERED TISSUE THICKNESS COMPENSATOR, now U.S. Patent Application Publication No. 2012/0253298; 
     U.S. patent application Ser. No. 13/433,179, entitled TISSUE THICKNESS COMPENSATORS FOR CIRCULAR SURGICAL STAPLERS, now U.S. Patent Application Publication No. 2012/0241505; 
     U.S. patent application Ser. No. 13/433,115, entitled TISSUE THICKNESS COMPENSATOR COMPRISING CAPSULES DEFINING A LOW PRESSURE ENVIRONMENT, now U.S. Pat. No. 9,204,880; 
     U.S. patent application Ser. No. 13/433,135, entitled MOVABLE MEMBER FOR USE WITH A TISSUE THICKNESS COMPENSATOR, now U.S. Patent Application Publication No. 2013/0256382; 
     U.S. patent application Ser. No. 13/433,129, entitled TISSUE THICKNESS COMPENSATOR COMPRISING A PLURALITY OF MEDICAMENTS, now U.S. Pat. No. 9,211,120; 
     U.S. patent application Ser. No. 13/433,140, entitled TISSUE THICKNESS COMPENSATOR AND METHOD FOR MAKING THE SAME, now U.S. Pat. No. 9,241,714; 
     U.S. patent application Ser. No. 13/433,147, entitled TISSUE THICKNESS COMPENSATOR COMPRISING CHANNELS, now U.S. Patent Application Publication No. 2013/0256369; 
     U.S. patent application Ser. No. 13/433,126, entitled TISSUE THICKNESS COMPENSATOR COMPRISING TISSUE INGROWTH FEATURES, now U.S. Patent Application Publication No. 2013/0256366; and 
     U.S. patent application Ser. No. 13/433,132, entitled DEVICES AND METHODS FOR ATTACHING TISSUE THICKNESS COMPENSATING MATERIALS TO SURGICAL STAPLING INSTRUMENTS, now U.S. Patent Application Publication No. 2013/0256373. 
     Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the various embodiments of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention. 
     Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment”, or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment”, or “in an embodiment”, or the like, in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features structures, or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of the present invention. 
     The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” referring to the portion closest to the clinician and the term “distal” referring to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute. 
     Various exemplary devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the person of ordinary skill in the art will readily appreciate that the various methods and devices disclosed herein can be used in numerous surgical procedures and applications including, for example, in connection with open surgical procedures. As the present Detailed Description proceeds, those of ordinary skill in the art will further appreciate that the various instruments disclosed herein can be inserted into a body in any way, such as through a natural orifice, through an incision or puncture hole formed in tissue, etc. The working portions or end effector portions of the instruments can be inserted directly into a patient&#39;s body or can be inserted through an access device that has a working channel through which the end effector and elongated shaft of a surgical instrument can be advanced. 
     Turning to the Drawings wherein like numerals denote like components throughout the several views,  FIG. 1  depicts a surgical instrument  10  that is capable of practicing several unique benefits. The surgical stapling instrument  10  is designed to manipulate and/or actuate various forms and sizes of end effectors  12  that are operably attached thereto. In the embodiment depicted in  FIGS. 1-1E , for example, the end effector  12  includes an elongated channel  14  that forms a lower jaw  13  of the end effector  12 . The elongated channel  14  is configured to support an “implantable” staple cartridge  30  and also movably support an anvil  20  that functions as an upper jaw  15  of the end effector  12 . 
     In various embodiments, the elongated channel  14  may be fabricated from, for example, 300 &amp; 400 Series, 17-4 &amp; 17-7 stainless steel, titanium, etc. and be formed with spaced side walls  16 . The anvil  20  may be fabricated from, for example, 300 &amp; 400 Series, 17-4 &amp; 17-7 stainless steel, titanium, etc. and have a staple forming undersurface, generally labeled as  22  that has a plurality of staple forming pockets  23  formed therein. See  FIGS. 1B-1E . In addition, the anvil  20  has a bifurcated ramp assembly  24  that protrudes proximally therefrom. An anvil pin  26  protrudes from each lateral side of the ramp assembly  24  to be received within a corresponding slot or opening  18  in the side walls  16  of the elongated channel  14  to facilitate its movable or pivotable attachment thereto. 
     Various forms of implantable staple cartridges may be employed with the various embodiments of the surgical instruments disclosed herein. Specific staple cartridge configurations and constructions will be discussed in further detail below. However, in the embodiment depicted in  FIG. 1A , an implantable staple cartridge  30  is shown. In at least one embodiment, the staple cartridge  30  has a body portion  31  that consists of a compressible hemostat material such as, for example, oxidized regenerated cellulose (“ORC”) or a bioabsorbable foam in which lines of unformed metal staples  32  are supported. In at least some embodiments, in order to prevent the staple from being affected and the hemostat material from being activated during the introduction and positioning process, the entire cartridge may be coated or wrapped in a biodegradable film  38  such as a polydioxanon film sold under the trademark PDS® or with a Polyglycerol sebacate (PGS) film or other biodegradable films formed from PGA (Polyglycolic acid, marketed under the trade mark Vicryl), PCL (Polycaprolactone), PLA or PLLA (Polylactic acid), PHA (polyhydroxyalkanoate), PGCL (poliglecaprone 25, sold under the trademark Monocryl) or a composite of PGA, PCL, PLA, PDS that would be impermeable until ruptured. The body  31  of staple cartridge  30  is sized to be removably supported within the elongated channel  14  as shown such that each staple  32  therein is aligned with corresponding staple forming pockets  23  in the anvil when the anvil  20  is driven into forming contact with the staple cartridge  30 . 
     In use, once the end effector  12  has been positioned adjacent the target tissue, the end effector  12  is manipulated to capture or clamp the target tissue between an upper face  36  of the staple cartridge  30  and the staple forming surface  22  of the anvil  20 . The staples  32  are formed by moving the anvil  20  in a path that is substantially parallel to the elongated channel  14  to bring the staple forming surface  22  and, more particularly, the staple forming pockets  23  therein into substantially simultaneous contact with the upper face  36  of the staple cartridge  30 . As the anvil  20  continues to move into the staple cartridge  30 , the legs  34  of the staples  32  contact a corresponding staple forming pocket  23  in anvil  20  which serves to bend the staple legs  34  over to form the staples  32  into a “B shape”. Further movement of the anvil  20  toward the elongated channel  14  will further compress and form the staples  32  to a desired final formed height “FF”. 
     The above-described staple forming process is generally depicted in  FIGS. 1B-1E . For example,  FIG. 1B  illustrates the end effector  12  with target tissue “T” between the anvil  20  and the upper face  36  of the implantable staple cartridge  30 .  FIG. 1C  illustrates the initial clamping position of the anvil  20  wherein the anvil has  20  been closed onto the target tissue “T” to clamp the target tissue “T” between the anvil  20  and the upper face  36  of the staple cartridge  30 .  FIG. 1D  illustrates the initial staple formation wherein the anvil  20  has started to compress the staple cartridge  30  such that the legs  34  of the staples  32  are starting to be formed by the staple forming pockets  23  in the anvil  20 .  FIG. 1E  illustrates the staple  32  in its final formed condition through the target tissue “T” with the anvil  20  removed for clarity purposes. Once the staples  32  have been formed and fastened to the target tissue “T”, the surgeon will move the anvil  20  to the open position to enable the cartridge body  31  and the staples  32  to remain affixed to the target tissue while the end effector  12  is being withdrawn from the patient. The end effector  12  forms all of the staples simultaneously as the two jaws  13 ,  15  are clamped together. The remaining “crushed” body materials  31  act as both a hemostat (the ORC) and a staple line reinforcement (PGA, PDS or any of the other film compositions mentioned above  38 ). Also, since the staples  32  never have to leave the cartridge body  31  during forming, the likelihood of the staples  32  being malformed during forming is minimized. As used herein the term “implantable” means that, in addition to the staples, the cartridge body materials that support the staples will also remain in the patient and may eventually be absorbed by the patient&#39;s body. Such implantable staple cartridges are distinguishable from prior cartridge arrangements that remain positioned within the end effector in their entirety after they have been fired. 
     In various implementations, the end effector  12  is configured to be coupled to an elongated shaft assembly  40  that protrudes from a handle assembly  100 . The end effector  12  (when closed) and the elongated shaft assembly  40  may have similar cross-sectional shapes and be sized to operably pass through a trocar tube or working channel in another form of access instrument. As used herein, the term “operably pass” means that the end effector and at least a portion of the elongated shaft assembly may be inserted through or passed through the channel or tube opening and can be manipulated therein as needed to complete the surgical stapling procedure. In some embodiments, when in a closed position, the jaws  13  and  15  of the end effector  12  may provide the end effector with a roughly circular cross-sectional shape that facilitates its passage through a circular passage/opening. However, the end effectors of various embodiments of the present invention, as well as the elongated shaft assembly embodiments, could conceivably be provided with other cross-sectional shapes that could otherwise pass through access passages and openings that have non-circular cross-sectional shapes. Thus, an overall size of a cross-section of a closed end effector will be related to the size of the passage or opening through which it is intended to pass. Thus, one end effector for example, may be referred to as a “5 mm” end effector which means it can operably pass through an opening that is at least approximately 5 mm in diameter. 
     In various embodiments, the elongated shaft assembly  40  may have an outer diameter that is substantially the same as the outer diameter of the end effector  12  when in a closed position. For example, a 5 mm end effector may be coupled to an elongated shaft assembly  40  that has 5 mm cross-sectional diameter. However, as the present Detailed Description proceeds, it will become apparent that various embodiments of the present may be effectively used in connection with different sizes of end effectors. For example, a 10 mm end effector may be attached to an elongated shaft that has a 5 mm cross-sectional diameter. Conversely, for those applications wherein a 10 mm or larger access opening or passage is provided, the elongated shaft assembly  40  may have a 10 mm (or larger) cross-sectional diameter, but may also be able to actuate a 5 mm or 10 mm end effector. Accordingly, the outer shaft  40  may have an outer diameter that is the same as or is different from the outer diameter of a closed end effector  12  attached thereto. 
     As depicted, the elongated shaft assembly  40  extends distally from the handle assembly  100  in a generally straight line to define a longitudinal axis A-A. In various embodiments, for example, the elongated shaft assembly  40  may be approximately 9-16 inches (229-406 mm) long. However, the elongated shaft assembly  40  may be provided in other lengths and, in other embodiments, may have joints therein or be otherwise configured to facilitate articulation of the end effector  12  relative to other portions of the shaft or handle assembly as will be discussed in further detail below. In various embodiments, the elongated shaft assembly  40  includes a spine member  50  that extends from the handle assembly  100  to the end effector  12 . The proximal end of the elongated channel  14  of the end effector  12  has a pair of retention trunnions  17  protruding therefrom that are sized to be received within corresponding trunnion openings or cradles  52  that are provided in a distal end of the spine member  50  to enable the end effector  12  to be removably coupled the elongated shaft assembly  40 . The spine member  50  may be fabricated from, for example, 6061 or 7075 aluminum, stainless steel, titanium, etc. 
     In various embodiments, the handle assembly  100  comprises a pistol grip-type housing that may be fabricated in two or more pieces for assembly purposes. For example, the handle assembly  100  as shown comprises a right hand case member  102  and a left hand case member (not illustrated) that are molded or otherwise fabricated from a polymer or plastic material and are designed to mate together. Such case members may be attached together by snap features, pegs and sockets molded or otherwise formed therein and/or by adhesive, screws, etc. The spine member  50  has a proximal end  54  that has a flange  56  formed thereon. The flange  56  is configured to be rotatably supported within a groove  106  formed by mating ribs  108  that protrude inwardly from each of the case members  102 ,  104 . Such arrangement facilitates the attachment of the spine member  50  to the handle assembly  100  while enabling the spine member  50  to be rotated relative to the handle assembly  100  about the longitudinal axis A-A in a 360° path. 
     As can be further seen in  FIG. 1 , the spine member  50  passes through and is supported by a mounting bushing  60  that is rotatably affixed to the handle assembly  100 . The mounting bushing  60  has a proximal flange  62  and a distal flange  64  that define a rotational groove  65  that is configured to rotatably receive a nose portion  101  of the handle assembly  100  therebetween. Such arrangement enables the mounting bushing  60  to rotate about longitudinal axis A-A relative to the handle assembly  100 . The spine member  50  is non-rotatably pinned to the mounting bushing  60  by a spine pin  66 . In addition, a rotation knob  70  is attached to the mounting bushing  60 . In one embodiment, for example, the rotation knob  70  has a hollow mounting flange portion  72  that is sized to receive a portion of the mounting bushing  60  therein. In various embodiments, the rotation knob  70  may be fabricated from, for example, glass or carbon filled Nylon, polycarbonate, Ultem®, etc. and is affixed to the mounting bushing  60  by the spine pin  66  as well. In addition, an inwardly protruding retention flange  74  is formed on the mounting flange portion  72  and is configured to extend into a radial groove  68  formed in the mounting bushing  60 . Thus, the surgeon may rotate the spine member  50  (and the end effector  12  attached thereto) about longitudinal axis A-A in a 360° path by grasping the rotation knob  70  and rotating it relative to the handle assembly  100 . 
     In various embodiments, the anvil  20  is retained in an open position by an anvil spring  21  and/or another biasing arrangement. The anvil  20  is selectively movable from the open position to various closed or clamping and firing positions by a firing system, generally designated as  109 . The firing system  109  includes a “firing member”  110  which, in various embodiments, comprises a hollow firing tube  110 . The hollow firing tube  110  is axially movable on the spine member  50  and thus forms the outer portion of the elongated shaft assembly  40 . The firing tube  110  may be fabricated from a polymer or other suitable material and have a proximal end that is attached to a firing yoke  114  of the firing system  109 . In various embodiments for example, the firing yoke  114  may be over-molded to the proximal end of the firing tube  110 . However, other fastener arrangements may be employed. 
     As can be seen in  FIG. 1 , the firing yoke  114  may be rotatably supported within a support collar  120  that is configured to move axially within the handle assembly  100 . In various embodiments, the support collar  120  has a pair of laterally extending fins that are sized to be slidably received within fin slots formed in the right and left hand case members. Thus, the support collar  120  may slide axially within the handle housing  100  while enabling the firing yoke  114  and firing tube  110  to rotate relative thereto about the longitudinal axis A-A. In various embodiments, a longitudinal slot is provided through the firing tube  110  to enable the spine pin  66  to extend therethrough into the spine member  50  while facilitating the axial travel of the firing tube  110  on the spine member  50 . 
     The firing system  109  further comprises a firing trigger  130  which serves to control the axial travel of the firing tube  110  on the spine member  50 . See  FIG. 1 . Such axial movement in the distal direction of the firing tube  110  into firing interaction with the anvil  20  is referred to herein as “firing motion”. As can be seen in  FIG. 1 , the firing trigger  130  is movably or pivotally coupled to the handle assembly  100  by a pivot pin  132 . A torsion spring  135  is employed to bias the firing trigger  130  away from the pistol grip portion  107  of the handle assembly  100  to an un-actuated “open” or starting position. As can be seen in  FIG. 1 , the firing trigger  130  has an upper portion  134  that is movably attached to (pinned) firing links  136  that are movably attached to (pinned) the support collar  120 . Thus, movement of the firing trigger  130  from the starting position ( FIG. 1 ) toward an ending position adjacent the pistol grip portion  107  of the handle assembly  100  will cause the firing yoke  114  and the firing tube  110  to move in the distal direction “DD”. Movement of the firing trigger  130  away from the pistol grip portion  107  of the handle assembly  100  (under the bias of the torsion spring  135 ) will cause the firing yoke  114  and firing tube  110  to move in the proximal direction “PD” on the spine member  50 . 
     Various embodiments of the present invention may be employed with different sizes and configurations of implantable staple cartridges. For example, the surgical instrument  10 , when used in connection with a first firing adapter  140 , may be used with a 5 mm end effector  12  that is approximately 20 mm long (or in other lengths) which supports an implantable staple cartridge  30 . Such end effector size may be particularly well-suited, for example, to complete relatively fine dissection and vascular transactions. However, as will be discussed in further detail below, the surgical instrument  10  may also be employed, for example, in connection with other sizes of end effectors and staple cartridges by replacing the first firing adapter  140  with a second firing adapter. In still other embodiments, the elongated shaft assembly  40  may configured to be attached to only one form or size of end effector. 
     One method of removably coupling the end effector  12  to the spine member  50  will now be explained. The coupling process is commenced by inserting the retention trunnions  17  on the elongated channel  14  into the trunnion cradles  52  in the spine member  50 . Thereafter, the surgeon advances the firing trigger  130  toward the pistol grip  107  of the housing assembly  100  to distally advance the firing tube  110  and the first firing adapter  140  over a proximal end portion  47  of the elongated channel  14  to thereby retain the trunnions  17  in their respective cradles  52 . Such position of the first firing adapter  140  over the trunnions  17  is referred to herein as the “coupled position”. Various embodiments of the present invention may also have an end effector locking assembly for locking the firing trigger  130  in position after an end effector  12  has been attached to the spine member  50 . 
     More specifically, one embodiment of the end effector locking assembly  160  includes a retention pin  162  that is movably supported in the upper portion  134  of the firing trigger  130 . As discussed above, the firing tube  110  must initially be advanced distally to the coupled position wherein the first firing adapter  140  retains the retention trunnions  17  of the end effector  12  in the trunnion cradles  52  in the spine member  50 . The surgeon advances the firing adapter  140  distally to the coupled position by pulling the firing trigger  130  from the starting position toward the pistol grip  107 . As the firing trigger  130  is initially actuated, the retention pin  162  is moved distally until the firing tube  110  has advanced the first firing adapter  140  to the coupled position at which point the retention pin  162  is biased into a locking cavity  164  formed in the case member. In various embodiments, when the retention pin  162  enters into the locking cavity  164 , the pin  162  may make an audible “click” or other sound, as well as provide a tactile indication to the surgeon that the end effector  12  has been “locked” onto the spine member  50 . In addition, the surgeon cannot inadvertently continue to actuate the firing trigger  130  to start to form staples  32  in the end effector  12  without intentionally biasing the retention pin  162  out of the locking cavity  164 . Similarly, if the surgeon releases the firing trigger  130  when in the coupled position, it is retained in that position by the retention pin  162  to prevent the firing trigger  130  from returning to the starting position and thereby releasing the end effector  12  from the spine member  50 . 
     Various embodiments of the present invention may further include a firing system lock button  137  that is pivotally attached to the handle assembly  100 . In one form, the firing system lock button  137  has a latch  138  formed on a distal end thereof that is oriented to engage the firing yoke  114  when the firing release button is in a first latching position. As can be seen in  FIG. 1 , a latch spring  139  serves to bias the firing system lock button  137  to the first latching position. In various circumstances, the latch  138  serves to engage the firing yoke  114  at a point where the position of the firing yoke  114  on the spine member  50  corresponds to a point wherein the first firing adapter  140  is about to distally advance up the clamping ramp  28  on the anvil  20 . It will be understood that, as the first firing adapter  140  advances axially up the clamping ramp  28 , the anvil  20  will move in a path such that its staple forming surface portion  22  is substantially parallel to the upper face  36  of the staple cartridge  30 . 
     After the end effector  12  has been coupled to the spine member  50 , the staple forming process is commenced by first depressing the firing system lock button  137  to enable the firing yoke  114  to be further moved distally on the spine member  50  and ultimately compress the anvil  20  into the staple cartridge  30 . After depressing the firing system lock button  137 , the surgeon continues to actuate the firing trigger  130  towards the pistol grip  107  thereby driving the first staple collar  140  up the corresponding staple forming ramp  29  to force the anvil  20  into forming contact with the staples  32  in the staple cartridge  30 . The firing system lock button  137  prevents the inadvertent forming of the staples  32  until the surgeon is ready to start that process. In this embodiment, the surgeon must depress the firing system lock button  137  before the firing trigger  130  may be further actuated to begin the staple forming process. 
     The surgical instrument  10  may be solely used as a tissue stapling device if so desired. However, various embodiments of the present invention may also include a tissue cutting system, generally designated as  170 . In at least one form, the tissue cutting system  170  comprises a knife member  172  that may be selectively advanced from an un-actuated position adjacent the proximal end of the end effector  12  to an actuated position by actuating a knife advancement trigger  200 . The knife member  172  is movably supported within the spine member  50  and is attached or otherwise protrudes from a knife rod  180 . The knife member  172  may be fabricated from, for example, 420 or 440 stainless steel with a hardness of greater than 38HRC (Rockwell Hardness C-scale) and have a tissue cutting edge  176  formed on the distal end  174  thereof and be configured to slidably extend through a slot in the anvil  20  and a centrally disposed slot  33  in the staple cartridge  30  to cut through tissue that is clamped in the end effector  12 . In various embodiments, the knife rod  180  extends through the spine member  50  and has a proximal end portion which drivingly interfaces with a knife transmission that is operably attached to the knife advance trigger  200 . In various embodiments, the knife advance trigger  200  is attached to pivot pin  132  such that it may be pivoted or otherwise actuated without actuating the firing trigger  130 . In various embodiments, a first knife gear  192  is also attached to the pivot pin  132  such that actuation of the knife advance trigger  200  also pivots the first knife gear  192 . A firing return spring  202  is attached between the first knife gear  192  and the handle housing  100  to bias the knife advancement trigger  200  to a starting or un-actuated position. 
     Various embodiments of the knife transmission also include a second knife gear  194  that is rotatably supported on a second gear spindle and in meshing engagement with the first knife gear  192 . The second knife gear  194  is in meshing engagement with a third knife gear  196  that is supported on a third gear spindle. Also supported on the third gear spindle  195  is a fourth knife gear  198 . The fourth knife gear  198  is adapted to drivingly engage a series of annular gear teeth or rings on a proximal end of the knife rod  180 . Thus, such arrangement enables the fourth knife gear  198  to axially drive the knife rod  180  in the distal direction “DD” or proximal direction “PD” while enabling the firing rod  180  to rotate about longitudinal axis A-A with respect to the fourth knife gear  198 . Accordingly, the surgeon may axially advance the firing rod  180  and ultimately the knife member  172  distally by pulling the knife advancement trigger  200  towards the pistol grip  107  of the handle assembly  100 . 
     Various embodiments of the present invention further include a knife lockout system  210  that prevents the advancement of the knife member  172  unless the firing trigger  130  has been pulled to the fully fired position. Such feature will therefore prevent the activation of the knife advancement system  170  unless the staples have first been fired or formed into the tissue. As can be seen in  FIG. 1 , various implementations of the knife lockout system  210  comprise a knife lockout bar  211  that is pivotally supported within the pistol grip portion  107  of the handle assembly  100 . The knife lockout bar  211  has an activation end  212  that is adapted to be engaged by the firing trigger  130  when the firing trigger  130  is in the fully fired position. In addition, the knife lockout bar  211  has a retaining hook  214  on its other end that is adapted to hookingly engage a latch rod  216  on the first cut gear  192 . A knife lock spring  218  is employed to bias the knife lockout bar  211  to a “locked” position wherein the retaining hook  214  is retained in engagement with the latch rod  216  to thereby prevent actuation of the knife advancement trigger  200  unless the firing trigger  130  is in the fully fired position. 
     After the staples have been “fired” (formed) into the target tissue, the surgeon may depress the firing trigger release button  167  to enable the firing trigger  130  to return to the starting position under the bias of the torsion spring  135  which enables the anvil  20  to be biased to an open position under the bias of spring  21 . When in the open position, the surgeon may withdraw the end effector  12  leaving the implantable staple cartridge  30  and staples  32  behind. In applications wherein the end effector was inserted through a passage, working channel, etc. the surgeon will return the anvil  20  to the closed position by activating the firing trigger  130  to enable the end effector  12  to be withdrawn out through the passage or working channel. If, however, the surgeon desires to cut the target tissue after firing the staples, the surgeon activates the knife advancement trigger  200  in the above-described manner to drive the knife bar  172  through the target tissue to the end of the end effector. Thereafter, the surgeon may release the knife advancement trigger  200  to enable the firing return spring  202  to cause the firing transmission to return the knife bar  172  to the starting (un-actuated) position. Once the knife bar  172  has been returned to the starting position, the surgeon may open the end effector jaws  13 ,  15  to release the implantable cartridge  30  within the patient and then withdraw the end effector  12  from the patient. Thus, such surgical instruments facilitate the use of small implantable staple cartridges that may be inserted through relatively smaller working channels and passages, while providing the surgeon with the option to fire the staples without cutting tissue or if desired to also cut tissue after the staples have been fired. 
     Various unique and novel embodiments of the present invention employ a compressible staple cartridge that supports staples in a substantially stationary position for forming contact by the anvil. In various embodiments, the anvil is driven into the unformed staples wherein, in at least one such embodiment, the degree of staple formation attained is dependent upon how far the anvil is driven into the staples. Such an arrangement provides the surgeon with the ability to adjust the amount of forming or firing pressure applied to the staples and thereby alter the final formed height of the staples. In other various embodiments of the present invention, surgical stapling arrangements can employ staple driving elements which can lift the staples toward the anvil. Such embodiments are described in greater detail further below. 
     In various embodiments, with regard to the embodiments described in detail above, the amount of firing motion that is applied to the movable anvil is dependent upon the degree of actuation of the firing trigger. For example, if the surgeon desires to attain only partially formed staples, then the firing trigger is only partially depressed inward towards the pistol grip  107 . To attain more staple formation, the surgeon simply compresses the firing trigger further which results in the anvil being further driven into forming contact with the staples. As used herein, the term “forming contact” means that the staple forming surface or staple forming pockets have contacted the ends of the staple legs and have started to form or bend the legs over into a formed position. The degree of staple formation refers to how far the staple legs have been folded over and ultimately relates to the forming height of the staple as referenced above. Those of ordinary skill in the art will further understand that, because the anvil  20  moves in a substantially parallel relationship with respect to the staple cartridge as the firing motions are applied thereto, the staples are formed substantially simultaneously with substantially the same formed heights. 
       FIGS. 2 and 3  illustrate an alternative end effector  12 ″ that is similar to the end effector  12 ′ described above, except with the following differences that are configured to accommodate a knife bar  172 ′. The knife bar  172 ′ is coupled to or protrudes from a knife rod  180  and is otherwise operated in the above described manner with respect to the knife bar  172 . However, in this embodiment, the knife bar  172 ′ is long enough to traverse the entire length of the end effector  12 ″ and therefore, a separate distal knife member is not employed in the end effector  12 ″. The knife bar  172 ′ has an upper transverse member  173 ′ and a lower transverse member  175 ′ formed thereon. The upper transverse member  173 ′ is oriented to slidably transverse a corresponding elongated slot  250  in anvil  20 ″ and the lower transverse member  175 ′ is oriented to traverse an elongated slot  252  in the elongated channel  14 ″ of the end effector  12 ″. A disengagement slot (not shown) is also provided in the anvil  20 ″ such that when the knife bar  172 ′ has been driven to an ending position within end effector  12 ″, the upper transverse member  173 ′ drops through the corresponding slot to enable the anvil  20 ″ to move to the open position to disengage the stapled and cut tissue. The anvil  20 ″ may be otherwise identical to anvil  20  described above and the elongated channel  14 ″ may be otherwise identical to elongated channel  14  described above. 
     In these embodiments, the anvil  20 ″ is biased to a fully open position ( FIG. 2 ) by a spring or other opening arrangement (not shown). The anvil  20 ″ is moved between the open and fully clamped positions by the axial travel of the firing adapter  150  in the manner described above. Once the firing adapter  150  has been advanced to the fully clamped position ( FIG. 3 ), the surgeon may then advance the knife bar  172 ″ distally in the manner described above. If the surgeon desires to use the end effector as a grasping device to manipulate tissue, the firing adapter may be moved proximally to allow the anvil  20 ″ to move away from the elongated channel  14 ″ as represented in  FIG. 4  in broken lines. In this embodiment, as the knife bar  172 ″ moves distally, the upper transverse member  173 ′ and the lower transverse member  175 ′ draw the anvil  20 ″ and elongated channel  14 ″ together to achieve the desired staple formation as the knife bar  172 ″ is advanced distally through the end effector  12 ″. See  FIG. 5 . Thus, in this embodiment, staple formation occurs simultaneously with tissue cutting, but the staples themselves may be sequentially formed as the knife bar  172 ″ is driven distally. 
     The unique and novel features of the various surgical staple cartridges and the surgical instruments of the present invention enable the staples in those cartridges to be arranged in one or more linear or non-linear lines. A plurality of such staple lines may be provided on each side of an elongated slot that is centrally disposed within the staple cartridge for receiving the tissue cutting member therethrough. In one arrangement, for example, the staples in one line may be substantially parallel with the staples in adjacent line(s) of staples, but offset therefrom. In still other embodiments, one or more lines of staples may be non-linear in nature. That is, the base of at least one staple in a line of staples may extend along an axis that is substantially transverse to the bases of other staples in the same staple line. For example, the lines of staples on each side of the elongated slot may have a zigzag appearance. 
     In various embodiments, a staple cartridge can comprise a cartridge body and a plurality of staples stored within the cartridge body. In use, the staple cartridge can be introduced into a surgical site and positioned on a side of the tissue being treated. In addition, a staple-forming anvil can be positioned on the opposite side of the tissue. In various embodiments, the anvil can be carried by a first jaw and the staple cartridge can be carried by a second jaw, wherein the first jaw and/or the second jaw can be moved toward the other. Once the staple cartridge and the anvil have been positioned relative to the tissue, the staples can be ejected from the staple cartridge body such that the staples can pierce the tissue and contact the staple-forming anvil. Once the staples have been deployed from the staple cartridge body, the staple cartridge body can then be removed from the surgical site. In various embodiments disclosed herein, a staple cartridge, or at least a portion of a staple cartridge, can be implanted with the staples. In at least one such embodiment, as described in greater detail further below, a staple cartridge can comprise a cartridge body which can be compressed, crushed, and/or collapsed by the anvil when the anvil is moved from an open position into a closed position. When the cartridge body is compressed, crushed, and/or collapsed, the staples positioned within the cartridge body can be deformed by the anvil. Alternatively, the jaw supporting the staple cartridge can be moved toward the anvil into a closed position. In either event, in various embodiments, the staples can be deformed while they are at least partially positioned within the cartridge body. In certain embodiments, the staples may not be ejected from the staple cartridge while, in some embodiments, the staples can be ejected from the staple cartridge along with a portion of the cartridge body. 
     Referring now to  FIGS. 6A-6D , a compressible staple cartridge, such as staple cartridge  1000 , for example, can comprise a compressible, implantable cartridge body  1010  and, in addition, a plurality of staples  1020  positioned in the compressible cartridge body  1010 , although only one staple  1020  is depicted in  FIGS. 6A-6D .  FIG. 6A  illustrates the staple cartridge  1000  supported by a staple cartridge support, or staple cartridge channel,  1030 , wherein the staple cartridge  1000  is illustrated in an uncompressed condition. In such an uncompressed condition, the anvil  1040  may or may not be in contact with the tissue T. In use, the anvil  1040  can be moved from an open position into contact with the tissue T as illustrated in  FIG. 6B  and position the tissue T against the cartridge body  1010 . Even though the anvil  1040  can position the tissue T against a tissue-contacting surface  1019  of staple cartridge body  1010 , referring again to  FIG. 6B , the staple cartridge body  1010  may be subjected to little, if any, compressive force or pressure at such point and the staples  1020  may remain in an unformed, or unfired, condition. As illustrated in  FIGS. 6A and 6B , the staple cartridge body  1010  can comprise one or more layers and the staple legs  1021  of staples  1020  can extend upwardly through these layers. In various embodiments, the cartridge body  1010  can comprise a first layer  1011 , a second layer  1012 , a third layer  1013 , wherein the second layer  1012  can be positioned intermediate the first layer  1011  and the third layer  1013 , and a fourth layer  1014 , wherein the third layer  1013  can be positioned intermediate the second layer  1012  and the fourth layer  1014 . In at least one embodiment, the bases  1022  of the staples  1020  can be positioned within cavities  1015  in the fourth layer  1014  and the staple legs  1021  can extend upwardly from the bases  1022  and through the fourth layer  1014 , the third layer  1013 , and the second layer  1012 , for example. In various embodiments, each deformable leg  1021  can comprise a tip, such as sharp tip  1023 , for example, which can be positioned in the second layer  1012 , for example, when the staple cartridge  1000  is in an uncompressed condition. In at least one such embodiment, the tips  1023  may not extend into and/or through the first layer  1011 , wherein, in at least one embodiment, the tips  1023  may not protrude through the tissue-contacting surface  1019  when the staple cartridge  1000  is in an uncompressed condition. In certain other embodiments, the sharp tips  1023  may be positioned in the third layer  1013 , and/or any other suitable layer, when the staple cartridge is in an uncompressed condition. In various alternative embodiments, a cartridge body of a staple cartridge may have any suitable number of layers such as less than four layers or more than four layers, for example. 
     In various embodiments, as described in greater detail below, the first layer  1011  can be comprised of a buttress material and/or plastic material, such as polydioxanone (PDS) and/or polyglycolic acid (PGA), for example, and the second layer  1012  can be comprised of a bioabsorbable foam material and/or a compressible haemostatic material, such as oxidized regenerated cellulose (ORC), for example. In various embodiments, one or more of the first layer  1011 , the second layer  1012 , the third layer  1013 , and the fourth layer  1014  may hold the staples  1020  within the staple cartridge body  1010  and, in addition, maintain the staples  1020  in alignment with one another. In various embodiments, the third layer  1013  can be comprised of a buttress material, or a fairly incompressible or inelastic material, which can be configured to hold the staple legs  1021  of the staples  1020  in position relative to one another. Furthermore, the second layer  1012  and the fourth layer  1014 , which are positioned on opposite sides of the third layer  1013 , can stabilize, or reduce the movement of, the staples  1020  even though the second layer  1012  and the fourth layer  1014  can be comprised of a compressible foam or elastic material. In certain embodiments, the staple tips  1023  of the staple legs  1021  can be at least partially embedded in the first layer  1011 . In at least one such embodiment, the first layer  1011  and the third layer  1013  can be configured to co-operatively and firmly hold the staple legs  1021  in position. In at least one embodiment, the first layer  1011  and the third layer  1013  can each be comprised of a sheet of bioabsorbable plastic, such as polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example, and the second layer  1012  and the fourth layer  1014  can each be comprised of at least one haemostatic material or agent. 
     Although the first layer  1011  can be compressible, the second layer  1012  can be substantially more compressible than the first layer  1011 . For example, the second layer  1012  can be about twice as compressible, about three times as compressible, about four times as compressible, about five times as compressible, and/or about ten times as compressible, for example, as the first layer  1011 . Stated another way, the second layer  1012  may compress about two times, about three times, about four times, about five times, and/or about ten times as much as first layer  1011 , for a given force. In certain embodiments, the second layer  1012  can be between about twice as compressible and about ten times as compressible, for example, as the first layer  1011 . In at least one embodiment, the second layer  1012  can comprise a plurality of air voids defined therein, wherein the amount and/or size of the air voids in the second layer  1012  can be controlled in order to provide a desired compressibility of the second layer  1012 . Similar to the above, although the third layer  1013  can be compressible, the fourth layer  1014  can be substantially more compressible than the third layer  1013 . For example, the fourth layer  1014  can be about twice as compressible, about three times as compressible, about four times as compressible, about five times as compressible, and/or about ten times as compressible, for example, as the third layer  1013 . Stated another way, the fourth layer  1014  may compress about two times, about three times, about four times, about five times, and/or about ten times as much as third layer  1013 , for a given force. In certain embodiments, the fourth layer  1014  can be between about twice as compressible and about ten times as compressible, for example, as the third layer  1013 . In at least one embodiment, the fourth layer  1014  can comprise a plurality of air voids defined therein, wherein the amount and/or size of the air voids in the fourth layer  1014  can be controlled in order to provide a desired compressibility of the fourth layer  1014 . In various circumstances, the compressibility of a cartridge body, or cartridge body layer, can be expressed in terms of a compression rate, i.e., a distance in which a layer is compressed for a given amount of force. For example, a layer having a high compression rate will compress a larger distance for a given amount of compressive force applied to the layer as compared to a layer having a lower compression rate. This being said, the second layer  1012  can have a higher compression rate than the first layer  1011  and, similarly, the fourth layer  1014  can have a higher compression rate than the third layer  1013 . In various embodiments, the second layer  1012  and the fourth layer  1014  can be comprised of the same material and can comprise the same compression rate. In various embodiments, the second layer  1012  and the fourth layer  1014  can be comprised of materials having different compression rates. Similarly, the first layer  1011  and the third layer  1013  can be comprised of the same material and can comprise the same compression rate. In certain embodiments, the first layer  1011  and the third layer  1013  can be comprised of materials having different compression rates. 
     As the anvil  1040  is moved toward its closed position, the anvil  1040  can contact tissue T and apply a compressive force to the tissue T and the staple cartridge  1000 , as illustrated in  FIG. 6C . In such circumstances, the anvil  1040  can push the top surface, or tissue-contacting surface  1019 , of the cartridge body  1010  downwardly toward the staple cartridge support  1030 . In various embodiments, the staple cartridge support  1030  can comprise a cartridge support surface  1031  which can be configured to support the staple cartridge  1000  as the staple cartridge  1000  is compressed between the cartridge support surface  1031  and the tissue-contacting surface  1041  of anvil  1040 . Owing to the pressure applied by the anvil  1040 , the cartridge body  1010  can be compressed and the anvil  1040  can come into contact with the staples  1020 . More particularly, in various embodiments, the compression of the cartridge body  1010  and the downward movement of the tissue-contacting surface  1019  can cause the tips  1023  of the staple legs  1021  to pierce the first layer  1011  of cartridge body  1010 , pierce the tissue T, and enter into forming pockets  1042  in the anvil  1040 . As the cartridge body  1010  is further compressed by the anvil  1040 , the tips  1023  can contact the walls defining the forming pockets  1042  and, as a result, the legs  1021  can be deformed or curled inwardly, for example, as illustrated in  FIG. 6C . As the staple legs  1021  are being deformed, as also illustrated in  FIG. 6C , the bases  1022  of the staples  1020  can be in contact with or supported by the staple cartridge support  1030 . In various embodiments, as described in greater detail below, the staple cartridge support  1030  can comprise a plurality of support features, such as staple support grooves, slots, or troughs  1032 , for example, which can be configured to support the staples  1020 , or at least the bases  1022  of the staples  1020 , as the staples  1020  are being deformed. As also illustrated in  FIG. 6C , the cavities  1015  in the fourth layer  1014  can collapse as a result of the compressive force applied to the staple cartridge body  1010 . In addition to the cavities  1015 , the staple cartridge body  1010  can further comprise one or more voids, such as voids  1016 , for example, which may or may not comprise a portion of a staple positioned therein, that can be configured to allow the cartridge body  1010  to collapse. In various embodiments, the cavities  1015  and/or the voids  1016  can be configured to collapse such that the walls defining the cavities and/or walls deflect downwardly and contact the cartridge support surface  1031  and/or contact a layer of the cartridge body  1010  positioned underneath the cavities and/or voids. 
     Upon comparing  FIG. 6B  and  FIG. 6C , it is evident that the second layer  1012  and the fourth layer  1014  have been substantially compressed by the compressive pressure applied by the anvil  1040 . It may also be noted that the first layer  1011  and the third layer  1013  have been compressed as well. As the anvil  1040  is moved into its closed position, the anvil  1040  may continue to further compress the cartridge body  1010  by pushing the tissue-contacting surface  1019  downwardly toward the staple cartridge support  1030 . As the cartridge body  1010  is further compressed, the anvil  1040  can deform the staples  1020  into their completely-formed shape as illustrated in  FIG. 6D . Referring to  FIG. 6D , the legs  1021  of each staple  1020  can be deformed downwardly toward the base  1022  of each staple  1020  in order to capture at least a portion of the tissue T, the first layer  1011 , the second layer  1012 , the third layer  1013 , and the fourth layer  1014  between the deformable legs  1021  and the base  1022 . Upon comparing  FIGS. 6C and 6D , it is further evident that the second layer  1012  and the fourth layer  1014  have been further substantially compressed by the compressive pressure applied by the anvil  1040 . It may also be noted upon comparing  FIGS. 6C and 6D  that the first layer  1011  and the third layer  1013  have been further compressed as well. After the staples  1020  have been completely, or at least sufficiently, formed, the anvil  1040  can be lifted away from the tissue T and the staple cartridge support  1030  can be moved away, and/or detached from, the staple cartridge  1000 . As depicted in  FIG. 6D , and as a result of the above, the cartridge body  1010  can be implanted with the staples  1020 . In various circumstances, the implanted cartridge body  1010  can support the tissue along the staple line. In some circumstances, a haemostatic agent, and/or any other suitable therapeutic medicament, contained within the implanted cartridge body  1010  can treat the tissue over time. A haemostatic agent, as mentioned above, can reduce the bleeding of the stapled and/or incised tissue while a bonding agent or tissue adhesive can provide strength to the tissue over time. The implanted cartridge body  1010  can be comprised of materials such as ORC (oxidized regenerated cellulose), extracellular proteins such as collagen, polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. In certain circumstances, the cartridge body  1010  can comprise an antibiotic and/or anti-microbial material, such as colloidal silver and/or triclosan, for example, which can reduce the possibility of infection in the surgical site. 
     In various embodiments, the layers of the cartridge body  1010  can be connected to one another. In at least one embodiment, the second layer  1012  can be adhered to the first layer  1011 , the third layer  1013  can be adhered to the second layer  1012 , and the fourth layer  1014  can be adhered to the third layer  1013  utilizing at least one adhesive, such as fibrin and/or protein hydrogel, for example. In certain embodiments, although not illustrated, the layers of the cartridge body  1010  can be connected together by interlocking mechanical features. In at least one such embodiment, the first layer  1011  and the second layer  1012  can each comprise corresponding interlocking features, such as a tongue and groove arrangement and/or a dovetail joint arrangement, for example. Similarly, the second layer  1012  and the third layer  1013  can each comprise corresponding interlocking features while the third layer  1013  and the fourth layer  1014  can each comprise corresponding interlocking features. In certain embodiments, although not illustrated, the staple cartridge  1000  can comprise one or more rivets, for example, which can extend through one or more layers of the cartridge body  1010 . In at least one such embodiment, each rivet can comprise a first end, or head, positioned adjacent to the first layer  1011  and a second head positioned adjacent to the fourth layer  1014  which can be either assembled to or formed by a second end of the rivet. Owing to the compressible nature of the cartridge body  1010 , in at least one embodiment, the rivets can compress the cartridge body  1010  such that the heads of the rivets can be recessed relative to the tissue-contacting surface  1019  and/or the bottom surface  1018  of the cartridge body  1010 , for example. In at least one such embodiment, the rivets can be comprised of a bioabsorbable material, such as polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. In certain embodiments, the layers of the cartridge body  1010  may not be connected to one another other than by the staples  1020  contained therein. In at least one such embodiment, the frictional engagement between the staple legs  1021  and the cartridge body  1010 , for example, can hold the layers of the cartridge body  1010  together and, once the staples have been formed, the layers can be captured within the staples  1020 . In certain embodiments, at least a portion of the staple legs  1021  can comprise a roughened surface or rough coating which can increase the friction forces between the staples  1020  and the cartridge body  1010 . 
     As described above, a surgical instrument can comprise a first jaw including the staple cartridge support  1030  and a second jaw including the anvil  1040 . In various embodiments, as described in greater detail further below, the staple cartridge  1000  can comprise one or more retention features which can be configured to engage the staple cartridge support  1030  and, as a result, releasably retain the staple cartridge  1000  to the staple cartridge support  1030 . In certain embodiments, the staple cartridge  1000  can be adhered to the staple cartridge support  1030  by at least one adhesive, such as fibrin and/or protein hydrogel, for example. In use, in at least one circumstance, especially in laparoscopic and/or endoscopic surgery, the second jaw can be moved into a closed position opposite the first jaw, for example, such that the first and second jaws can be inserted through a trocar into a surgical site. In at least one such embodiment, the trocar can define an approximately 5 mm aperture, or cannula, through which the first and second jaws can be inserted. In certain embodiments, the second jaw can be moved into a partially-closed position intermediate the open position and the closed position which can allow the first and second jaws to be inserted through the trocar without deforming the staples  1020  contained in the staple cartridge body  1010 . In at least one such embodiment, the anvil  1040  may not apply a compressive force to the staple cartridge body  1010  when the second jaw is in its partially-closed intermediate position while, in certain other embodiments, the anvil  1040  can compress the staple cartridge body  1010  when the second jaw is in its partially-closed intermediate position. Even though the anvil  1040  can compress the staple cartridge body  1010  when it is in such an intermediate position, the anvil  1040  may not sufficiently compress the staple cartridge body  1010  such that the anvil  1040  comes into contact with the staples  1020  and/or such that the staples  1020  are deformed by the anvil  1040 . Once the first and second jaws have been inserted through the trocar into the surgical site, the second jaw can be opened once again and the anvil  1040  and the staple cartridge  1000  can be positioned relative to the targeted tissue as described above. 
     In various embodiments, referring now to  FIGS. 7A-7D , an end effector of a surgical stapler can comprise an implantable staple cartridge  1100  positioned intermediate an anvil  1140  and a staple cartridge support  1130 . Similar to the above, the anvil  1140  can comprise a tissue-contacting surface  1141 , the staple cartridge  1100  can comprise a tissue-contacting surface  1119 , and the staple cartridge support  1130  can comprise a support surface  1131  which can be configured to support the staple cartridge  1100 . Referring to  FIG. 7A , the anvil  1140  can be utilized to position the tissue T against the tissue contacting surface  1119  of staple cartridge  1100  without deforming the staple cartridge  1100  and, when the anvil  1140  is in such a position, the tissue-contacting surface  1141  can be positioned a distance  1101   a  away from the staple cartridge support surface  1131  and the tissue-contacting surface  1119  can be positioned a distance  1102   a  away from the staple cartridge support surface  1131 . Thereafter, as the anvil  1140  is moved toward the staple cartridge support  1130 , referring now to  FIG. 7B , the anvil  1140  can push the top surface, or tissue-contacting surface  1119 , of staple cartridge  1100  downwardly and compress the first layer  1111  and the second layer  1112  of cartridge body  1110 . As the layers  1111  and  1112  are compressed, referring again to  FIG. 7B , the second layer  1112  can be crushed and the legs  1121  of staples  1120  can pierce the first layer  1111  and enter into the tissue T. In at least one such embodiment, the staples  1120  can be at least partially positioned within staple cavities, or voids,  1115  in the second layer  1112  and, when the second layer  1112  is compressed, the staple cavities  1115  can collapse and, as a result, allow the second layer  1112  to collapse around the staples  1120 . In various embodiments, the second layer  1112  can comprise cover portions  1116  which can extend over the staple cavities  1115  and enclose, or at least partially enclose, the staple cavities  1115 .  FIG. 7B  illustrates the cover portions  1116  being crushed downwardly into the staple cavities  1115 . In certain embodiments, the second layer  1112  can comprise one or more weakened portions which can facilitate the collapse of the second layer  1112 . In various embodiments, such weakened portions can comprise score marks, perforations, and/or thin cross-sections, for example, which can facilitate a controlled collapse of the cartridge body  1110 . In at least one embodiment, the first layer  1111  can comprise one or more weakened portions which can facilitate the penetration of the staple legs  1121  through the first layer  1111 . In various embodiments, such weakened portions can comprise score marks, perforations, and/or thin cross-sections, for example, which can be aligned, or at least substantially aligned, with the staple legs  1121 . 
     When the anvil  1140  is in a partially closed, unfired position, referring again to  FIG. 7A , the anvil  1140  can be positioned a distance  1101   a  away from the cartridge support surface  1131  such that a gap is defined therebetween. This gap can be filled by the staple cartridge  1100 , having a staple cartridge height  1102   a , and the tissue T. As the anvil  1140  is moved downwardly to compress the staple cartridge  1100 , referring again to  FIG. 7B , the distance between the tissue contacting surface  1141  and the cartridge support surface  1131  can be defined by a distance  1101   b  which is shorter than the distance  1101   a . In various circumstances, the gap between the tissue-contacting surface  1141  of anvil  1140  and the cartridge support surface  1131 , defined by distance  1101   b , may be larger than the original, undeformed staple cartridge height  1102   a . As the anvil  1140  is moved closer to the cartridge support surface  1131 , referring now to  FIG. 7C , the second layer  1112  can continue to collapse and the distance between the staple legs  1121  and the forming pockets  1142  can decrease. Similarly, the distance between the tissue-contacting surface  1141  and the cartridge support surface  1131  can decrease to a distance  1101   c  which, in various embodiments, may be greater than, equal to, or less than the original, undeformed cartridge height  1102   a . Referring now to  FIG. 7D , the anvil  1140  can be moved into a final, fired position in which the staples  1120  have been fully formed, or at least formed to a desired height. In such a position, the tissue-contacting surface  1141  of anvil  1140  can be a distance  1101   d  away from the cartridge support surface  1131 , wherein the distance  1101   d  can be shorter than the original, undeformed cartridge height  1102   a . As also illustrated in  FIG. 7D , the staple cavities  1115  may be fully, or at least substantially, collapsed and the staples  1120  may be completely, or at least substantially, surrounded by the collapsed second layer  1112 . In various circumstances, the anvil  1140  can be thereafter moved away from the staple cartridge  1100 . Once the anvil  1140  has been disengaged from the staple cartridge  1100 , the cartridge body  1110  can at least partially re-expand in various locations, i.e., locations intermediate adjacent staples  1120 , for example. In at least one embodiment, the crushed cartridge body  1110  may not resiliently re-expand. In various embodiments, the formed staples  1120  and, in addition, the cartridge body  1110  positioned intermediate adjacent staples  1120  may apply pressure, or compressive forces, to the tissue T which may provide various therapeutic benefits. 
     As discussed above, referring again to the embodiment illustrated in  FIG. 7A , each staple  1120  can comprise staple legs  1121  extending therefrom. Although staples  1120  are depicted as comprising two staple legs  1121 , various staples can be utilized which can comprise one staple leg or, alternatively, more than two staple legs, such as three staple legs or four staple legs, for example. As illustrated in  FIG. 7A , each staple leg  1121  can be embedded in the second layer  1112  of the cartridge body  1110  such that the staples  1120  are secured within the second layer  1112 . In various embodiments, the staples  1120  can be inserted into the staple cavities  1115  in cartridge body  1110  such that the tips  1123  of the staple legs  1121  enter into the cavities  1115  before the bases  1122 . After the tips  1123  have been inserted into the cavities  1115 , in various embodiments, the tips  1123  can be pressed into the cover portions  1116  and incise the second layer  1112 . In various embodiments, the staples  1120  can be seated to a sufficient depth within the second layer  1112  such that the staples  1120  do not move, or at least substantially move, relative to the second layer  1112 . In certain embodiments, the staples  1120  can be seated to a sufficient depth within the second layer  1112  such that the bases  1122  are positioned or embedded within the staple cavities  1115 . In various other embodiments, the bases  1122  may not be positioned or embedded within the second layer  1112 . In certain embodiments, referring again to  FIG. 7A , the bases  1122  may extend below the bottom surface  1118  of the cartridge body  1110 . In certain embodiments, the bases  1122  can rest on, or can be directly positioned against, the cartridge support surface  1130 . In various embodiments, the cartridge support surface  1130  can comprise support features extending therefrom and/or defined therein wherein, in at least one such embodiment, the bases  1122  of the staples  1120  may be positioned within and supported by one or more support grooves, slots, or troughs,  1132 , for example, in the staple cartridge support  1130 , as described in greater detail further below. 
     In various embodiments, referring now to  FIGS. 8 and 9 , a staple cartridge, such as staple cartridge  1200 , for example, can comprise a compressible, implantable cartridge body  1210  comprising an outer layer  1211  and an inner layer  1212 . Similar to the above, the staple cartridge  1200  can comprise a plurality of staples  1220  positioned within the cartridge body  1210 . In various embodiments, each staple  1220  can comprise a base  1222  and one or more staple legs  1221  extending therefrom. In at least one such embodiment, the staple legs  1221  can be inserted into the inner layer  1212  and seated to a depth in which the bases  1222  of the staples  1220  abut and/or are positioned adjacent to the bottom surface  1218  of the inner layer  1212 , for example. In the embodiment depicted in  FIGS. 8 and 9 , the inner layer  1212  does not comprise staple cavities configured to receive a portion of the staples  1220  while, in other embodiments, the inner layer  1212  can comprise such staple cavities. In various embodiments, further to the above, the inner layer  1212  can be comprised of a compressible material, such as bioabsorbable foam and/or oxidized regenerated cellulose (ORC), for example, which can be configured to allow the cartridge body  1210  to collapse when a compressive load is applied thereto. In various embodiments, the inner layer  1212  can be comprised of a lyophilized foam comprising polylactic acid (PLA) and/or polyglycolic acid (PGA), for example. The ORC may be commercially available under the trade name Surgicel and can comprise a loose woven fabric (like a surgical sponge), loose fibers (like a cotton ball), and/or a foam. In at least one embodiment, the inner layer  1212  can be comprised of a material including medicaments, such as freeze-dried thrombin and/or fibrin, for example, contained therein and/or coated thereon which can be water-activated and/or activated by fluids within the patient&#39;s body, for example. In at least one such embodiment, the freeze-dried thrombin and/or fibrin can be held on a Vicryl (PGA) matrix, for example. In certain circumstances, however, the activatable medicaments can be unintentionally activated when the staple cartridge  1200  is inserted into a surgical site within the patient, for example. In various embodiments, referring again to  FIGS. 8 and 9 , the outer layer  1211  can be comprised of a water impermeable, or at least substantially water impermeable, material such that liquids do not come into contact with, or at least substantially contact, the inner layer  1212  until after the cartridge body  1210  has been compressed and the staple legs have penetrated the outer layer  1211  and/or after the outer layer  1211  has been incised in some fashion. In various embodiments, the outer layer  1211  can be comprised of a buttress material and/or plastic material, such as polydioxanone (PDS) and/or polyglycolic acid (PGA), for example. In certain embodiments, the outer layer  1211  can comprise a wrap which surrounds the inner layer  1212  and the staples  1220 . More particularly, in at least one embodiment, the staples  1220  can be inserted into the inner layer  1212  and the outer layer  1211  can be wrapped around the sub-assembly comprising the inner layer  1212  and the staples  1220  and then sealed. 
     In various embodiments described herein, the staples of a staple cartridge can be fully formed by an anvil when the anvil is moved into a closed position. In various other embodiments, referring now to  FIGS. 10-13 , the staples of a staple cartridge, such as staple cartridge  4100 , for example, can be deformed by an anvil when the anvil is moved into a closed position and, in addition, by a staple driver system which moves the staples toward the closed anvil. The staple cartridge  4100  can comprise a compressible cartridge body  4110  which can be comprised of a foam material, for example, and a plurality of staples  4120  at least partially positioned within the compressible cartridge body  4110 . In various embodiments, the staple driver system can comprise a driver holder  4160 , a plurality of staple drivers  4162  positioned within the driver holder  4160 , and a staple cartridge pan  4180  which can be configured to retain the staple drivers  4162  in the driver holder  4160 . In at least one such embodiment, the staple drivers  4162  can be positioned within one or more slots  4163  in the driver holder  4160  wherein the sidewalls of the slots  4163  can assist in guiding the staple drivers  4162  upwardly toward the anvil. In various embodiments, the staples  4120  can be supported within the slots  4163  by the staple drivers  4162  wherein, in at least one embodiment, the staples  4120  can be entirely positioned in the slots  4163  when the staples  4120  and the staple drivers  4162  are in their unfired positions. In certain other embodiments, at least a portion of the staples  4120  can extend upwardly through the open ends  4161  of slots  4163  when the staples  4120  and staple drivers  4162  are in their unfired positions. In at least one such embodiment, referring primarily now to  FIG. 11 , the bases of the staples  4120  can be positioned within the driver holder  4160  and the tips of the staples  4120  can be embedded within the compressible cartridge body  4110 . In certain embodiments, approximately one-third of the height of the staples  4120  can be positioned within the driver holder  4160  and approximately two-thirds of the height of the staples  4120  can be positioned within the cartridge body  4110 . In at least one embodiment, referring to  FIG. 10A , the staple cartridge  4100  can further comprise a water impermeable wrap or membrane  4111  surrounding the cartridge body  4110  and the driver holder  4160 , for example. 
     In use, the staple cartridge  4100  can be positioned within a staple cartridge channel, for example, and the anvil can be moved toward the staple cartridge  4100  into a closed position. In various embodiments, the anvil can contact and compress the compressible cartridge body  4110  when the anvil is moved into its closed position. In certain embodiments, the anvil may not contact the staples  4120  when the anvil is in its closed position. In certain other embodiments, the anvil may contact the legs of the staples  4120  and at least partially deform the staples  4120  when the anvil is moved into its closed position. In either event, the staple cartridge  4100  can further comprise one or more sleds  4170  which can be advanced longitudinally within the staple cartridge  4100  such that the sleds  4170  can sequentially engage the staple drivers  4162  and move the staple drivers  4162  and the staples  4120  toward the anvil. In various embodiments, the sleds  4170  can slide between the staple cartridge pan  4180  and the staple drivers  4162 . In embodiments where the closure of the anvil has started the forming process of the staples  4120 , the upward movement of the staples  4120  toward the anvil can complete the forming process and deform the staples  4120  to their fully formed, or at least desired, height. In embodiments where the closure of the anvil has not deformed the staples  4120 , the upward movement of the staples  4120  toward the anvil can initiate and complete the forming process and deform the staples  4120  to their fully formed, or at least desired, height. In various embodiments, the sleds  4170  can be advanced from a proximal end of the staple cartridge  4100  to a distal end of the staple cartridge  4100  such that the staples  4120  positioned in the proximal end of the staple cartridge  4100  are fully formed before the staples  4120  positioned in the distal end of the staple cartridge  4100  are fully formed. In at least one embodiment, referring to  FIG. 12 , the sleds  4170  can each comprise at least one angled or inclined surface  4711  which can be configured to slide underneath the staple drivers  4162  and lift the staple drivers  4162  as illustrated in  FIG. 13 . 
     In various embodiments, further to the above, the staples  4120  can be formed in order to capture at least a portion of the tissue T and at least a portion of the compressible cartridge body  4110  of the staple cartridge  4100  therein. After the staples  4120  have been formed, the anvil and the staple cartridge channel  4130  of the surgical stapler can be moved away from the implanted staple cartridge  4100 . In various circumstances, the cartridge pan  4180  can be fixedly engaged with the staple cartridge channel  4130  wherein, as a result, the cartridge pan  4180  can become detached from the compressible cartridge body  4110  as the staple cartridge channel  4130  is pulled away from the implanted cartridge body  4110 . In various embodiments, referring again to  FIG. 10 , the cartridge pan  4180  can comprise opposing side walls  4181  between which the cartridge body  4110  can be removably positioned. In at least one such embodiment, the compressible cartridge body  4110  can be compressed between the side walls  4181  such that the cartridge body  4110  can be removably retained therebetween during use and releasably disengaged from the cartridge pan  4180  as the cartridge pan  4180  is pulled away. In at least one such embodiment, the driver holder  4160  can be connected to the cartridge pan  4180  such that the driver holder  4160 , the drivers  4162 , and/or the sleds  4170  can remain in the cartridge pan  4180  when the cartridge pan  4180  is removed from the surgical site. In certain other embodiments, the drivers  4162  can be ejected from the driver holder  4160  and left within the surgical site. In at least one such embodiment, the drivers  4162  can be comprised of a bioabsorbable material, such as polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. In various embodiments, the drivers  4162  can be attached to the staples  4120  such that the drivers  4162  are deployed with the staples  4120 . In at least one such embodiment, each driver  4162  can comprise a trough configured to receive the bases of the staples  4120 , for example, wherein, in at least one embodiment, the troughs can be configured to receive the staple bases in a press-fit and/or snap-fit manner. 
     In certain embodiments, further to the above, the driver holder  4160  and/or the sleds  4170  can be ejected from the cartridge pan  4180 . In at least one such embodiment, the sleds  4170  can slide between the cartridge pan  4180  and the driver holder  4160  such that, as the sleds  4170  are advanced in order to drive the staple drivers  4162  and staples  4120  upwardly, the sleds  4170  can move the driver holder  4160  upwardly out of the cartridge pan  4180  as well. In at least one such embodiment, the driver holder  4160  and/or the sleds  4170  can be comprised of a bioabsorbable material, such as polyglycolic acid (PGA) which is marketed under the trade name Vicryl, polylactic acid (PLA or PLLA), polydioxanone (PDS), polyhydroxyalkanoate (PHA), poliglecaprone 25 (PGCL) which is marketed under the trade name Monocryl, polycaprolactone (PCL), and/or a composite of PGA, PLA, PDS, PHA, PGCL and/or PCL, for example. In various embodiments, the sleds  4170  can be integrally formed and/or attached to a drive bar, or cutting member, which pushes the sleds  4170  through the staple cartridge  4100 . In such embodiments, the sleds  4170  may not be ejected from the cartridge pan  4180  and may remain with the surgical stapler while, in other embodiments in which the sleds  4170  are not attached to the drive bar, the sleds  4170  may be left in the surgical site. In any event, further to the above, the compressibility of the cartridge body  4110  can allow thicker staple cartridges to be used within an end effector of a surgical stapler as the cartridge body  4110  can compress, or shrink, when the anvil of the stapler is closed. In certain embodiments, as a result of the staples being at least partially deformed upon the closure of the anvil, taller staples, such as staples having an approximately 0.18″ staple height, for example, could be used, wherein approximately 0.12″ of the staple height can be positioned within the compressible layer  4110  and wherein the compressible layer  4110  can have an uncompressed height of approximately 0.14″, for example. 
     In many embodiments described herein, a staple cartridge can comprise a plurality of staples therein. In various embodiments, such staples can be comprised of a metal wire deformed into a substantially U-shaped configuration having two staple legs. Other embodiments are envisioned in which staples can comprise different configurations such as two or more wires that have been joined together having three or more staple legs. In various embodiments, the wire, or wires, used to form the staples can comprise a round, or at least substantially round, cross-section. In at least one embodiment, the staple wires can comprise any other suitable cross-section, such as square and/or rectangular cross-sections, for example. In certain embodiments, the staples can be comprised of plastic wires. In at least one embodiment, the staples can be comprised of plastic-coated metal wires. In various embodiments, a cartridge can comprise any suitable type of fastener in addition to or in lieu of staples. In at least one such embodiment, such a fastener can comprise pivotable arms which are folded when engaged by an anvil. In certain embodiments, two-part fasteners could be utilized. In at least one such embodiment, a staple cartridge can comprise a plurality of first fastener portions and an anvil can comprise a plurality of second fastener portions which are connected to the first fastener portions when the anvil is compressed against the staple cartridge. In certain embodiments, as described above, a sled or driver can be advanced within a staple cartridge in order to complete the forming process of the staples. In certain embodiments, a sled or driver can be advanced within an anvil in order to move one or more forming members downwardly into engagement with the opposing staple cartridge and the staples, or fasteners, positioned therein. 
     In various embodiments described herein, a staple cartridge can comprise four rows of staples stored therein. In at least one embodiment, the four staple rows can be arranged in two inner staple rows and two outer staple rows. In at least one such embodiment, an inner staple row and an outer staple row can be positioned on a first side of a cutting member, or knife, slot within the staple cartridge and, similarly, an inner staple row and an outer staple row can be positioned on a second side of the cutting member, or knife, slot. In certain embodiments, a staple cartridge may not comprise a cutting member slot; however, such a staple cartridge may comprise a designated portion configured to be incised by a cutting member in lieu of a staple cartridge slot. In various embodiments, the inner staple rows can be arranged within the staple cartridge such that they are equally, or at least substantially equally, spaced from the cutting member slot. Similarly, the outer staple rows can be arranged within the staple cartridge such that they are equally, or at least substantially equally, spaced from the cutting member slot. In various embodiments, a staple cartridge can comprise more than or less than four rows of staples stored within a staple cartridge. In at least one embodiment, a staple cartridge can comprise six rows of staples. In at least one such embodiment, the staple cartridge can comprise three rows of staples on a first side of a cutting member slot and three rows of staples on a second side of the cutting member slot. In certain embodiments, a staple cartridge may comprise an odd number of staple rows. For example, a staple cartridge may comprise two rows of staples on a first side of a cutting member slot and three rows of staples on a second side of the cutting member slot. In various embodiments, the staple rows can comprise staples having the same, or at least substantially the same, unformed staple height. In certain other embodiments, one or more of the staple rows can comprise staples having a different unformed staple height than the other staples. In at least one such embodiment, the staples on a first side of a cutting member slot may have a first unformed height and the staples on a second side of a cutting member slot may have a second unformed height which is different than the first height, for example. 
     In various embodiments, as described above, a staple cartridge can comprise a cartridge body including a plurality of staple cavities defined therein. The cartridge body can comprise a deck and a top deck surface wherein each staple cavity can define an opening in the deck surface. As also described above, a staple can be positioned within each staple cavity such that the staples are stored within the cartridge body until they are ejected therefrom. Prior to being ejected from the cartridge body, in various embodiments, the staples can be contained with the cartridge body such that the staples do not protrude above the deck surface. As the staples are positioned below the deck surface, in such embodiments, the possibility of the staples becoming damaged and/or prematurely contacting the targeted tissue can be reduced. In various circumstances, the staples can be moved between an unfired position in which they do not protrude from the cartridge body and a fired position in which they have emerged from the cartridge body and can contact an anvil positioned opposite the staple cartridge. In various embodiments, the anvil, and/or the forming pockets defined within the anvil, can be positioned a predetermined distance above the deck surface such that, as the staples are being deployed from the cartridge body, the staples are deformed to a predetermined formed height. In some circumstances, the thickness of the tissue captured between the anvil and the staple cartridge may vary and, as a result, thicker tissue may be captured within certain staples while thinner tissue may be captured within certain other staples. In either event, the clamping pressure, or force, applied to the tissue by the staples may vary from staple to staple or vary between a staple on one end of a staple row and a staple on the other end of the staple row, for example. In certain circumstances, the gap between the anvil and the staple cartridge deck can be controlled such that the staples apply a certain minimum clamping pressure within each staple. In some such circumstances, however, significant variation of the clamping pressure within different staples may still exist. Surgical stapling instruments are disclosed in U.S. Pat. No. 7,380,696, which issued on Jun. 3, 2008, the entire disclosure of which is incorporated by reference herein. An illustrative multi-stroke handle for the surgical stapling and severing instrument is described in greater detail in the co-pending and co-owned U.S. patent application entitled SURGICAL STAPLING INSTRUMENT INCORPORATING A MULTISTROKE FIRING POSITION INDICATOR AND RETRACTION MECHANISM, Ser. No. 10/674,026, now U.S. Pat. No. 7,364,061, which issued on Apr. 29, 2008, the disclosure of which is hereby incorporated by reference in its entirety. Other applications consistent with the present invention may incorporate a single firing stroke, such as described in co-pending and commonly owned U.S. patent application SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS, Ser. No. 10/441,632, now U.S. Pat. No. 7,000,818, which issued on Feb. 21, 2006, the disclosure of which is hereby incorporated by reference in its entirety. 
     In various embodiments described herein, a staple cartridge can comprise means for compensating for the thickness of the tissue captured within the staples deployed from the staple cartridge. In various embodiments, referring to  FIG. 14 , a staple cartridge, such as staple cartridge  10000 , for example, can include a rigid first portion, such as support portion  10010 , for example, and a compressible second portion, such as tissue thickness compensator  10020 , for example. In at least one embodiment, referring primarily to  FIG. 16 , the support portion  10010  can comprise a cartridge body, a top deck surface  10011 , and a plurality of staple cavities  10012  wherein, similar to the above, each staple cavity  10012  can define an opening in the deck surface  10011 . A staple  10030 , for example, can be removably positioned in each staple cavity  10012 . In at least one such embodiment, each staple  10030  can comprise a base  10031  and one or more legs  10032  extending from the base  10031 . Prior to the staples  10030  being deployed, as also described in greater detail below, the bases  10031  of the staples  10030  can be supported by staple drivers positioned within the support portion  10010  and, concurrently, the legs  10032  of the staples  10030  can be at least partially contained within the staple cavities  10012 . In various embodiments, the staples  10030  can be deployed between an unfired position and a fired position such that the legs  10032  move through the tissue thickness compensator  10020 , penetrate through a top surface of the tissue thickness compensator  10020 , penetrate the tissue T, and contact an anvil positioned opposite the staple cartridge  10000 . As the legs  10032  are deformed against the anvil, the legs  10032  of each staple  10030  can capture a portion of the tissue thickness compensator  10020  and a portion of the tissue T within each staple  10030  and apply a compressive force to the tissue. Further to the above, the legs  10032  of each staple  10030  can be deformed downwardly toward the base  10031  of the staple to form a staple entrapment area  10039  in which the tissue T and the tissue thickness compensator  10020  can be captured. In various circumstances, the staple entrapment area  10039  can be defined between the inner surfaces of the deformed legs  10032  and the inner surface of the base  10031 . The size of the entrapment area for a staple can depend on several factors such as the length of the legs, the diameter of the legs, the width of the base, and/or the extent in which the legs are deformed, for example. 
     In previous embodiments, a surgeon was often required to select the appropriate staples having the appropriate staple height for the tissue being stapled. For example, a surgeon could select tall staples for use with thick tissue and short staples for use with thin tissue. In some circumstances, however, the tissue being stapled did not have a consistent thickness and, thus, some staples were unable to achieve the desired fired configuration. For example,  FIG. 48  illustrates a tall staple used in thin tissue. Referring now to  FIG. 49 , when a tissue thickness compensator, such as tissue thickness compensator  10020 , for example, is used with thin tissue, for example, the larger staple may be formed to a desired fired configuration. 
     Owing to the compressibility of the tissue thickness compensator, the tissue thickness compensator can compensate for the thickness of the tissue captured within each staple. More particularly, referring now to  FIGS. 43 and 44 , a tissue thickness compensator, such as tissue thickness compensator  10020 , for example, can consume larger and/or smaller portions of the staple entrapment area  10039  of each staple  10030  depending on the thickness and/or type of tissue contained within the staple entrapment area  10039 . For example, if thinner tissue T is captured within a staple  10030 , the tissue thickness compensator  10020  can consume a larger portion of the staple entrapment area  10039  as compared to circumstances where thicker tissue T is captured within the staple  10030 . Correspondingly, if thicker tissue T is captured within a staple  10030 , the tissue thickness compensator  10020  can consume a smaller portion of the staple entrapment area  10039  as compared to the circumstances where thinner tissue T is captured within the staple  10030 . In this way, the tissue thickness compensator can compensate for thinner tissue and/or thicker tissue and assure that a compressive pressure is applied to the tissue irrespective, or at least substantially irrespective, of the tissue thickness captured within the staples. In addition to the above, the tissue thickness compensator  10020  can compensate for different types, or compressibilities, of tissues captured within different staples  10030 . Referring now to  FIG. 44 , the tissue thickness compensator  10020  can apply a compressive force to vascular tissue T which can include vessels V and, as a result, restrict the flow of blood through the less compressible vessels V while still applying a desired compressive pressure to the surrounding tissue T. In various circumstances, further to the above, the tissue thickness compensator  10020  can also compensate for malformed staples. Referring to  FIG. 45 , the malformation of various staples  10030  can result in larger staple entrapment areas  10039  being defined within such staples. Owing to the resiliency of the tissue thickness compensator  10020 , referring now to  FIG. 46 , the tissue thickness compensator  10020  positioned within malformed staples  10030  may still apply a sufficient compressive pressure to the tissue T even though the staple entrapment areas  10039  defined within such malformed staples  10030  may be enlarged. In various circumstances, the tissue thickness compensator  10020  located intermediate adjacent staples  10030  can be biased against the tissue T by properly-formed staples  10030  surrounding a malformed staple  10030  and, as a result, apply a compressive pressure to the tissue surrounding and/or captured within the malformed staple  10030 , for example. In various circumstances, a tissue thickness compensator can compensate for different tissue densities which can arise due to calcifications, fibrous areas, and/or tissue that has been previously stapled or treated, for example. 
     In various embodiments, a fixed, or unchangeable, tissue gap can be defined between the support portion and the anvil and, as a result, the staples may be deformed to a predetermined height regardless of the thickness of the tissue captured within the staples. When a tissue thickness compensator is used with these embodiments, the tissue thickness compensator can adapt to the tissue captured between the anvil and the support portion staple cartridge and, owing to the resiliency of the tissue thickness compensator, the tissue thickness compensator can apply an additional compressive pressure to the tissue. Referring now to  FIGS. 50-55 , a staple  10030  has been formed to a predefined height H. With regard to  FIG. 50 , a tissue thickness compensator has not been utilized and the tissue T consumes the entirety of the staple entrapment area  10039 . With regard to  FIG. 57 , a portion of a tissue thickness compensator  10020  has been captured within the staple  10030 , compressed the tissue T, and consumed at least a portion of the staple entrapment area  10039 . Referring now to  FIG. 52 , thin tissue T has been captured within the staple  10030 . In this embodiment, the compressed tissue T has a height of approximately 2/9H and the compressed tissue thickness compensator  10020  has a height of approximately 7/9H, for example. Referring now to  FIG. 53 , tissue T having an intermediate thickness has been captured within the staple  10030 . In this embodiment, the compressed tissue T has a height of approximately 4/9H and the compressed tissue thickness compensator  10020  has a height of approximately 5/9H, for example. Referring now to  FIG. 54 , tissue T having an intermediate thickness has been captured within the staple  10030 . In this embodiment, the compressed tissue T has a height of approximately ⅔H and the compressed tissue thickness compensator  10020  has a height of approximately ⅓H, for example. Referring now to  FIG. 53 , thick tissue T has been captured within the staple  10030 . In this embodiment, the compressed tissue T has a height of approximately 8/9H and the compressed tissue thickness compensator  10020  has a height of approximately 1/9H, for example. In various circumstances, the tissue thickness compensator can comprise a compressed height which comprises approximately 10% of the staple entrapment height, approximately 20% of the staple entrapment height, approximately 30% of the staple entrapment height, approximately 40% of the staple entrapment height, approximately 50% of the staple entrapment height, approximately 60% of the staple entrapment height, approximately 70% of the staple entrapment height, approximately 80% of the staple entrapment height, and/or approximately 90% of the staple entrapment height, for example. 
     In various embodiments, the staples  10030  can comprise any suitable unformed height. In certain embodiments, the staples  10030  can comprise an unformed height between approximately 2 mm and approximately 4.8 mm, for example. The staples  10030  can comprise an unformed height of approximately 2.0 mm, approximately 2.5 mm, approximately 3.0 mm, approximately 3.4 mm, approximately 3.5 mm, approximately 3.8 mm, approximately 4.0 mm, approximately 4.1 mm, and/or approximately 4.8 mm, for example. In various embodiments, the height H to which the staples can be deformed can be dictated by the distance between the deck surface  10011  of the support portion  10010  and the opposing anvil. In at least one embodiment, the distance between the deck surface  10011  and the tissue-contacting surface of the anvil can be approximately 0.097″, for example. The height H can also be dictated by the depth of the forming pockets defined within the anvil. In at least one embodiment, the forming pockets can have a depth measured from the tissue-contacting surface, for example. In various embodiments, as described in greater detail below, the staple cartridge  10000  can further comprise staple drivers which can lift the staples  10030  toward the anvil and, in at least one embodiment, lift, or “overdrive”, the staples above the deck surface  10011 . In such embodiments, the height H to which the staples  10030  are formed can also be dictated by the distance in which the staples  10030  are overdriven. In at least one such embodiment, the staples  10030  can be overdriven by approximately 0.028″, for example, and can result in the staples  10030  being formed to a height of approximately 0.189″, for example. In various embodiments, the staples  10030  can be formed to a height of approximately 0.8 mm, approximately 1.0 mm, approximately 1.5 mm, approximately 1.8 mm, approximately 2.0 mm, and/or approximately 2.25 mm, for example. In certain embodiments, the staples can be formed to a height between approximately 2.25 mm and approximately 3.0 mm, for example. Further to the above, the height of the staple entrapment area of a staple can be determined by the formed height of the staple and the width, or diameter, of the wire comprising the staple. In various embodiments, the height of the staple entrapment area  10039  of a staple  10030  can comprise the formed height H of the staple less two diameter widths of the wire. In certain embodiments, the staple wire can comprise a diameter of approximately 0.0089″, for example. In various embodiments, the staple wire can comprise a diameter between approximately 0.0069″ and approximately 0.0119″, for example. In at least one exemplary embodiment, the formed height H of a staple  10030  can be approximately 0.189″ and the staple wire diameter can be approximately 0.0089″ resulting in a staple entrapment height of approximately 0.171″, for example. 
     In various embodiments, further to the above, the tissue thickness compensator can comprise an uncompressed, or pre-deployed, height and can be configured to deform to one of a plurality of compressed heights. In certain embodiments, the tissue thickness compensator can comprise an uncompressed height of approximately 0.125″, for example. In various embodiments, the tissue thickness compensator can comprise an uncompressed height of greater than or equal to approximately 0.080″, for example. In at least one embodiment, the tissue thickness compensator can comprise an uncompressed, or pre-deployed, height which is greater than the unfired height of the staples. In at least one embodiment, the uncompressed, or pre-deployed, height of the tissue thickness compensator can be approximately 10% taller, approximately 20% taller, approximately 30% taller, approximately 40% taller, approximately 50% taller, approximately 60% taller, approximately 70% taller, approximately 80% taller, approximately 90% taller, and/or approximately 100% taller than the unfired height of the staples, for example. In at least one embodiment, the uncompressed, or pre-deployed, height of the tissue thickness compensator can be up to approximately 100% taller than the unfired height of the staples, for example. In certain embodiments, the uncompressed, or pre-deployed, height of the tissue thickness compensator can be over 100% taller than the unfired height of the staples, for example. In at least one embodiment, the tissue thickness compensator can comprise an uncompressed height which is equal to the unfired height of the staples. In at least one embodiment, the tissue thickness compensator can comprise an uncompressed height which is less than the unfired height of the staples. In at least one embodiment, the uncompressed, or pre-deployed, height of the thickness compensator can be approximately 10% shorter, approximately 20% shorter, approximately 30% shorter, approximately 40% shorter, approximately 50% shorter, approximately 60% shorter, approximately 70% shorter, approximately 80% shorter, and/or approximately 90% shorter than the unfired height of the staples, for example. In various embodiments, the compressible second portion can comprise an uncompressed height which is taller than an uncompressed height of the tissue T being stapled. In certain embodiments, the tissue thickness compensator can comprise an uncompressed height which is equal to an uncompressed height of the tissue T being stapled. In various embodiments, the tissue thickness compensator can comprise an uncompressed height which is shorter than an uncompressed height of the tissue T being stapled. 
     As described above, a tissue thickness compensator can be compressed within a plurality of formed staples regardless of whether thick tissue or thin tissue is captured within the staples. In at least one exemplary embodiment, the staples within a staple line, or row, can be deformed such that the staple entrapment area of each staple comprises a height of approximately 2.0 mm, for example, wherein the tissue T and the tissue thickness compensator can be compressed within this height. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.75 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 0.25 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.50 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 0.50 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.25 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 0.75 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.0 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 1.0 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 0.75 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 1.25 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 1.50 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 0.50 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. In certain circumstances, the tissue T can comprise a compressed height of approximately 0.25 mm within the staple entrapment area while the tissue thickness compensator can comprise a compressed height of approximately 1.75 mm within the staple entrapment area, thereby totaling the approximately 2.0 mm staple entrapment area height, for example. 
     In various embodiments, further to the above, the tissue thickness compensator can comprise an uncompressed height which is less than the fired height of the staples. In certain embodiments, the tissue thickness compensator can comprise an uncompressed height which is equal to the fired height of the staples. In certain other embodiments, the tissue thickness compensator can comprise an uncompressed height which is taller than the fired height of the staples. In at least one such embodiment, the uncompressed height of a tissue thickness compensator can comprise a thickness which is approximately 110% of the formed staple height, approximately 120% of the formed staple height, approximately 130% of the formed staple height, approximately 140% of the formed staple height, approximately 150% of the formed staple height, approximately 160% of the formed staple height, approximately 170% of the formed staple height, approximately 180% of the formed staple height, approximately 190% of the formed staple height, and/or approximately 200% of the formed staple height, for example. In certain embodiments, the tissue thickness compensator can comprise an uncompressed height which is more than twice the fired height of the staples. In various embodiments, the tissue thickness compensator can comprise a compressed height which is from approximately 85% to approximately 150% of the formed staple height, for example. In various embodiments, as described above, the tissue thickness compensator can be compressed between an uncompressed thickness and a compressed thickness. In certain embodiments, the compressed thickness of a tissue thickness compensator can be approximately 10% of its uncompressed thickness, approximately 20% of its uncompressed thickness, approximately 30% of its uncompressed thickness, approximately 40% of its uncompressed thickness, approximately 50% of its uncompressed thickness, approximately 60% of its uncompressed thickness, approximately 70% of its uncompressed thickness, approximately 80% of its uncompressed thickness, and/or approximately 90% of its uncompressed thickness, for example. In various embodiments, the uncompressed thickness of the tissue thickness compensator can be approximately two times, approximately ten times, approximately fifty times, and/or approximately one hundred times thicker than its compressed thickness, for example. In at least one embodiment, the compressed thickness of the tissue thickness compensator can be between approximately 60% and approximately 99% of its uncompressed thickness. In at least one embodiment, the uncompressed thickness of the tissue thickness compensator can be at least 50% thicker than its compressed thickness. In at least one embodiment, the uncompressed thickness of the tissue thickness compensator can be up to one hundred times thicker than its compressed thickness. In various embodiments, the compressible second portion can be elastic, or at least partially elastic, and can bias the tissue T against the deformed legs of the staples. In at least one such embodiment, the compressible second portion can resiliently expand between the tissue T and the base of the staple in order to push the tissue T against the legs of the staple. In certain embodiments, discussed in further detail below, the tissue thickness compensator can be positioned intermediate the tissue T and the deformed staple legs. In various circumstances, as a result of the above, the tissue thickness compensator can be configured to consume any gaps within the staple entrapment area. 
     In various embodiments, the tissue thickness compensator may comprise materials characterized by one or more of the following properties: biocompatible, bioabsorable, bioresorbable, biodurable, biodegradable, compressible, fluid absorbable, swellable, self-expandable, bioactive, medicament, pharmaceutically active, anti-adhesion, haemostatic, antibiotic, anti-microbial, anti-viral, nutritional, adhesive, permeable, hydrophilic and/or hydrophobic, for example. In various embodiments, a surgical instrument comprising an anvil and a staple cartridge may comprise a tissue thickness compensator associated with the anvil and/or staple cartridge comprising at least one of a haemostatic agent, such as fibrin and thrombin, an antibiotic, such as doxycpl, and mendicant, such as matrix metalloproteinases (MMPs). 
     In various embodiments, the tissue thickness compensator may comprise synthetic and/or non-synthetic materials. The tissue thickness compensator may comprise a polymeric composition comprising one or more synthetic polymers and/or one or more non-synthetic polymers. The synthetic polymer may comprise a synthetic absorbable polymer and/or a synthetic non-absorbable polymer. In various embodiments, the polymeric composition may comprise a biocompatible foam, for example. The biocompatible foam may comprise a porous, open cell foam and/or a porous, closed cell foam, for example. The biocompatible foam may have a uniform pore morphology or may have a gradient pore morphology (i.e. small pores gradually increasing in size to large pores across the thickness of the foam in one direction). In various embodiments, the polymeric composition may comprise one or more of a porous scaffold, a porous matrix, a gel matrix, a hydrogel matrix, a solution matrix, a filamentous matrix, a tubular matrix, a composite matrix, a membranous matrix, a biostable polymer, and a biodegradable polymer, and combinations thereof. For example, the tissue thickness compensator may comprise a foam reinforced by a filamentous matrix or may comprise a foam having an additional hydrogel layer that expands in the presence of bodily fluids to further provide the compression on the tissue. In various embodiments, a tissue thickness compensator could also be comprised of a coating on a material and/or a second or third layer that expands in the presence of bodily fluids to further provide the compression on the tissue. Such a layer could be a hydrogel that could be a synthetic and/or naturally derived material and could be either biodurable and/or biodegradable, for example. In various embodiments, the tissue thickness compensator may comprise a microgel or a nanogel. The hydrogel may comprise carbohydrate-derived microgels and/or nanogels. In certain embodiments, a tissue thickness compensator may be reinforced with fibrous non-woven materials or fibrous mesh type elements, for example, that can provide additional flexibility, stiffness, and/or strength. In various embodiments, a tissue thickness compensator that has a porous morphology which exhibits a gradient structure such as, for example, small pores on one surface and larger pores on the other surface. Such morphology could be more optimal for tissue in-growth or haemostatic behavior. Further, the gradient could be also compositional with a varying bio-absorption profile. A short term absorption profile may be preferred to address hemostasis while a long term absorption profile may address better tissue healing without leakages. 
     Examples of non-synthetic materials include, but are not limited to, lyophilized polysaccharide, glycoprotein, bovine pericardium, collagen, gelatin, fibrin, fibrinogen, elastin, proteoglycan, keratin, albumin, hydroxyethyl cellulose, cellulose, oxidized cellulose, oxidized regenerated cellulose (ORC), hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethylcellulose, chitan, chitosan, casein, alginate, and combinations thereof. 
     Examples of synthetic absorbable materials include, but are not limited to, poly(lactic acid) (PLA), poly(L-lactic acid) (PLLA), polycaprolactone (PCL), polyglycolic acid (PGA), poly(trimethylene carbonate) (TMC), polyethylene terephthalate (PET), polyhydroxyalkanoate (PHA), a copolymer of glycolide and ε-caprolactone (PGCL), a copolymer of glycolide and -trimethylene carbonate, poly(glycerol sebacate) (PGS), poly(dioxanone) (PDS), polyesters, poly(orthoesters), polyoxaesters, polyetheresters, polycarbonates, polyamide esters, polyanhydrides, polysaccharides, poly(ester-amides), tyrosine-based polyarylates, polyamines, tyrosine-based polyiminocarbonates, tyrosine-based polycarbonates, poly(D,L-lactide-urethane), poly(hydroxybutyrate), poly(B-hydroxybutyrate), poly(ε-caprolactone), polyethyleneglycol (PEG), poly[bis(carboxylatophenoxy)phosphazene]poly(amino acids), pseudo-poly(amino acids), absorbable polyurethanes, poly(phosphazine), polyphosphazenes, polyalkyleneoxides, polyacrylamides, polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinyl alcohols, poly(caprolactone), polyacrylic acid, polyacetate, polypropylene, aliphatic polyesters, glycerols, copoly(ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyalkylene oxalates, and combinations thereof. In various embodiments, the polyester is may be selected from the group consisting of polylactides, polyglycolides, trimethylene carbonates, polydioxanones, polycaprolactones, polybutesters, and combinations thereof. 
     In various embodiments, the synthetic absorbable polymer may comprise one or more of 90/10 poly(glycolide-L-lactide) copolymer, commercially available from Ethicon, Inc. under the trade designation VICRYL (polyglactic 910), polyglycolide, commercially available from American Cyanamid Co. under the trade designation DEXON, polydioxanone, commercially available from Ethicon, Inc. under the trade designation PDS, poly(glycolide-trimethylene carbonate) random block copolymer, commercially available from American Cyanamid Co. under the trade designation MAXON, 75/25 poly(glycolide-ε-caprolactone-poliglecaprolactone 25) copolymer, commercially available from Ethicon under the trade designation MONOCRYL, for example. 
     Examples of synthetic non-absorbable materials include, but are not limited to, polyurethane, polypropylene (PP), polyethylene (PE), polycarbonate, polyamides, such as nylon, polyvinylchloride (PVC), polymethylmetacrylate (PMMA), polystyrene (PS), polyester, polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polytrifluorochloroethylene (PTFCE), polyvinylfluoride (PVF), fluorinated ethylene propylene (FEP), polyacetal, polysulfone, silicons, and combinations thereof. The synthetic non-absorbable polymers may include, but are not limited to, foamed elastomers and porous elastomers, such as, for example, silicone, polyisoprene, and rubber. In various embodiments, the synthetic polymers may comprise expanded polytetrafluoroethylene (ePTFE), commercially available from W. L. Gore &amp; Associates, Inc. under the trade designation GORE-TEX Soft Tissue Patch and co-polyetherester urethane foam commercially available from Polyganics under the trade designation NASOPORE. 
     In various embodiments, the polymeric composition may comprise from approximately 50% to approximately 90% by weight of the polymeric composition of PLLA and approximately 50% to approximately 10% by weight of the polymeric composition of PCL, for example. In at least one embodiment, the polymeric composition may comprise approximately 70% by weight of PLLA and approximately 30% by weight of PCL, for example. In various embodiments, the polymeric composition may comprise from approximately 55% to approximately 85% by weight of the polymeric composition of PGA and 15% to 45% by weight of the polymeric composition of PCL, for example. In at least one embodiment, the polymeric composition may comprise approximately 65% by weight of PGA and approximately 35% by weight of PCL, for example. In various embodiments, the polymeric composition may comprise from approximately 90% to approximately 95% by weight of the polymeric composition of PGA and approximately 5% to approximately 10% by weight of the polymeric composition of PLA, for example. 
     In various embodiments, the synthetic absorbable polymer may comprise a bioabsorbable, biocompatible elastomeric copolymer. Suitable bioabsorbable, biocompatible elastomeric copolymers include but are not limited to copolymers of ε-caprolactone and glycolide (preferably having a mole ratio of ε-caprolactone to glycolide of from about 30:70 to about 70:30, preferably 35:65 to about 65:35, and more preferably 45:55 to 35:65); elastomeric copolymers of ε-caprolactone and lactide, including L-lactide, D-lactide blends thereof or lactic acid copolymers (preferably having a mole ratio of ε-caprolactone to lactide of from about 35:65 to about 65:35 and more preferably 45:55 to 30:70) elastomeric copolymers of p-dioxanone (1,4-dioxan-2-one) and lactide including L-lactide, D-lactide and lactic acid (preferably having a mole ratio of p-dioxanone to lactide of from about 40:60 to about 60:40); elastomeric copolymers of ε-caprolactone and p-dioxanone (preferably having a mole ratio of ε-caprolactone to p-dioxanone of from about 30:70 to about 70:30); elastomeric copolymers of p-dioxanone and trimethylene carbonate (preferably having a mole ratio of p-dioxanone to trimethylene carbonate of from about 30:70 to about 70:30); elastomeric copolymers of trimethylene carbonate and glycolide (preferably having a mole ratio of trimethylene carbonate to glycolide of from about 30:70 to about 70:30); elastomeric copolymer of trimethylene carbonate and lactide including L-lactide, D-lactide, blends thereof or lactic acid copolymers (preferably having a mole ratio of trimethylene carbonate to lactide of from about 30:70 to about 70:30) and blends thereof. In one embodiment, the elastomeric copolymer is a copolymer of glycolide and ε-caprolactone. In another embodiment, the elastomeric copolymer is a copolymer of lactide and ε-caprolactone. 
     The disclosures of U.S. Pat. No. 5,468,253, entitled ELASTOMERIC MEDICAL DEVICE, which issued on Nov. 21, 1995, and U.S. Pat. No. 6,325,810, entitled FOAM BUTTRESS FOR STAPLING APPARATUS, which issued on Dec. 4, 2001, are hereby incorporated by reference in their respective entireties. 
     In various embodiments, the tissue thickness compensator may comprise an emulsifier. Examples of emulsifiers may include, but are not limited to, water-soluble polymers, such as, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), polypropylene glycol (PPG), PLURONICS, TWEENS, polysaccharides and combinations thereof. 
     In various embodiments, the tissue thickness compensator may comprise a surfactant. Examples of surfactants may include, but are not limited to, polyacrylic acid, methalose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, dialkylphenoxy poly(ethyleneoxy)ethanol, and polyoxamers. 
     In various embodiments, the polymeric composition may comprise a pharmaceutically active agent. The polymeric composition may release a therapeutically effective amount of the pharmaceutically active agent. In various embodiments, the pharmaceutically active agent may be released as the polymeric composition is desorbed/absorbed. In various embodiments, the pharmaceutically active agent may be released into fluid, such as, for example, blood, passing over or through the polymeric composition. Examples of pharmaceutically active agents may include, but are not limited to, haemostatic agents and drugs, such as, for example, fibrin, thrombin, and oxidized regenerated cellulose (ORC); anti-inflammatory drugs, such as, for example, diclofenac, aspirin, naproxen, sulindac, and hydrocortisone; antibiotic and antimicrobial drug or agents, such as, for example, triclosan, ionic silver, ampicillin, gentamicin, polymyxin B, chloramphenicol; and anticancer agents, such as, for example, cisplatin, mitomycin, adriamycin. 
     In various embodiments, the polymeric composition may comprise a haemostatic material. The tissue thickness compensator may comprise haemostatic materials comprising poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(caprolactone), poly(dioxanone), polyalkyleneoxides, copoly(ether-esters), collagen, gelatin, thrombin, fibrin, fibrinogen, fibronectin, elastin, albumin, hemoglobin, ovalbumin, polysaccharides, hyaluronic acid, chondroitin sulfate, hydroxyethyl starch, hydroxyethyl cellulose, cellulose, oxidized cellulose, hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, chitan, chitosan, agarose, maltose, maltodextrin, alginate, clotting factors, methacrylate, polyurethanes, cyanoacrylates, platelet agonists, vasoconstrictors, alum, calcium, RGD peptides, proteins, protamine sulfate, ε-amino caproic acid, ferric sulfate, ferric subsulfates, ferric chloride, zinc, zinc chloride, aluminum chloride, aluminum sulfates, aluminum acetates, permanganates, tannins, bone wax, polyethylene glycols, fucans and combinations thereof. The tissue thickness compensator may be characterized by haemostatic properties. 
     The polymeric composition of a tissue thickness compensator may be characterized by percent porosity, pore size, and/or hardness, for example. In various embodiments, the polymeric composition may have a percent porosity from approximately 30% by volume to approximately 99% by volume, for example. In certain embodiments, the polymeric composition may have a percent porosity from approximately 60% by volume to approximately 98% by volume, for example. In various embodiments, the polymeric composition may have a percent porosity from approximately 85% by volume to approximately 97% by volume, for example. In at least one embodiment, the polymeric composition may comprise approximately 70% by weight of PLLA and approximately 30% by weight of PCL, for example, and can comprise approximately 90% porosity by volume, for example. In at least one such embodiment, as a result, the polymeric composition would comprise approximately 10% copolymer by volume. In at least one embodiment, the polymeric composition may comprise approximately 65% by weight of PGA and approximately 35% by weight of PCL, for example, and can have a percent porosity from approximately 93% by volume to approximately 95% by volume, for example. In various embodiments, the polymeric composition may comprise greater than 85% porosity by volume. The polymeric composition may have a pore size from approximately 5 micrometers to approximately 2000 micrometers, for example. In various embodiments, the polymeric composition may have a pore size between approximately 10 micrometers to approximately 100 micrometers, for example. In at least one such embodiment, the polymeric composition can comprise a copolymer of PGA and PCL, for example. In certain embodiments, the polymeric composition may have a pore size between approximately 100 micrometers to approximately 1000 micrometers, for example. In at least one such embodiment, the polymeric composition can comprise a copolymer of PLLA and PCL, for example. 
     According to certain aspects, the hardness of a polymeric composition may be expressed in terms of the Shore Hardness, which can defined as the resistance to permanent indentation of a material as determined with a durometer, such as a Shore Durometer. In order to assess the durometer value for a given material, a pressure is applied to the material with a durometer indenter foot in accordance with ASTM procedure D2240-00, entitled, “Standard Test Method for Rubber Property-Durometer Hardness”, the entirety of which is incorporated herein by reference. The durometer indenter foot may be applied to the material for a sufficient period of time, such as 15 seconds, for example, wherein a reading is then taken from the appropriate scale. Depending on the type of scale being used, a reading of 0 can be obtained when the indenter foot completely penetrates the material, and a reading of 100 can be obtained when no penetration into the material occurs. This reading is dimensionless. In various embodiments, the durometer may be determined in accordance with any suitable scale, such as Type A and/or Type OO scales, for example, in accordance with ASTM D2240-00. In various embodiments, the polymeric composition of a tissue thickness compensator may have a Shore A hardness value from approximately 4 A to approximately 16 A, for example, which is approximately 45 OO to approximately 65 OO on the Shore OO range. In at least one such embodiment, the polymeric composition can comprise a PLLA/PCL copolymer or a PGA/PCL copolymer, for example. In various embodiments, the polymeric composition of a tissue thickness compensator may have a Shore A Hardness value of less than 15 A. In various embodiments, the polymeric composition of a tissue thickness compensator may have a Shore A Hardness value of less than 10 A. In various embodiments, the polymeric composition of a tissue thickness compensator may have a Shore A Hardness value of less than 5 A. In certain embodiments, the polymeric material may have a Shore OO composition value from approximately 35 OO to approximately 75 OO, for example. 
     In various embodiments, the polymeric composition may have at least two of the above-identified properties. In various embodiments, the polymeric composition may have at least three of the above-identified properties. The polymeric composition may have a porosity from 85% to 97% by volume, a pore size from 5 micrometers to 2000 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example. In at least one embodiment, the polymeric composition may comprise 70% by weight of the polymeric composition of PLLA and 30% by weight of the polymeric composition of PCL having a porosity of 90% by volume, a pore size from 100 micrometers to 1000 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example. In at least one embodiment, the polymeric composition may comprise 65% by weight of the polymeric composition of PGA and 35% by weight of the polymeric composition of PCL having a porosity from 93% to 95% by volume, a pore size from 10 micrometers to 100 micrometers, and a Shore A hardness value from 4 A to 16 A and Shore OO hardness value from 45 OO to 65 OO, for example. 
     In various embodiments, the tissue thickness compensator may comprise a material that expands. As discussed above, the tissue thickness compensator may comprise a compressed material that expands when uncompressed or deployed, for example. In various embodiments, the tissue thickness compensator may comprise a self-expanding material formed in situ. In various embodiments, the tissue thickness compensator may comprise at least one precursor selected to spontaneously crosslink when contacted with at least one of other precursor(s), water, and/or bodily fluids. In various embodiments, a first precursor may contact one or more other precursors to form an expandable and/or swellable tissue thickness compensator. In various embodiments, the tissue thickness compensator may comprise a fluid-swellable composition, such as a water-swellable composition, for example. In various embodiments, the tissue thickness compensator may comprise a gel comprising water. 
     In various embodiments, the tissue thickness compensator may comprise a biodegradable foam having an encapsulation comprising dry hydrogel particles or granules embedded therein. Without wishing to be bound to any particular theory, the encapsulations in the foam may be formed by contacting an aqueous solution of a hydrogel precursor and an organic solution of biocompatible materials to form the foam. In various embodiments, the aqueous solution and organic solution may form micelles. The aqueous solution and organic solution may be dried to encapsulate dry hydrogel particles or granules within the foam. For example, a hydrogel precursor, such as a hydrophilic polymer, may be dissolved in water to form a dispersion of micelles. The aqueous solution may contact an organic solution of dioxane comprising poly(glycolic acid) and polycaprolactone. The aqueous and organic solutions may be lyophilized to form a biodegradable foam having dry hydrogel particles or granules dispersed therein. Without wishing to be bound to any particular theory, it is believed that the micelles form the encapsulation having the dry hydrogel particles or granules dispersed within the foam structure. In certain embodiments, the encapsulation may be ruptured, and the dry hydrogel particles or granules may contact a fluid, such as a bodily fluid, and expand. 
     In various embodiments, as described above, the tissue thickness compensator may comprise an initial thickness and an expanded thickness. In certain embodiments, the initial thickness of a tissue thickness compensator can be approximately 0.001% of its expanded thickness, approximately 0.01% of its expanded thickness, approximately 0.1% of its expanded thickness, approximately 1% of its expanded thickness, approximately 10% of its expanded thickness, approximately 20% of its expanded thickness, approximately 30% of its expanded thickness, approximately 40% of its expanded thickness, approximately 50% of its expanded thickness, approximately 60% of its expanded thickness, approximately 70% of its expanded thickness, approximately 80% of its expanded thickness, and/or approximately 90% of its expanded thickness, for example. In various embodiments, the expanded thickness of the tissue thickness compensator can be approximately two times, approximately five times, approximately ten times, approximately fifty times, approximately one hundred times, approximately two hundred times, approximately three hundred times, approximately four hundred times, approximately five hundred times, approximately six hundred times, approximately seven hundred times, approximately eight hundred times, approximately nine hundred times, and/or approximately one thousand times thicker than its initial thickness, for example. In various embodiments, the initial thickness of the tissue thickness compensator can be up to 1% its expanded thickness, up to 5% its expanded thickness, up to 10% its expanded thickness, and up to 50% its expanded thickness. In various embodiments, the expanded thickness of the tissue thickness compensator can be at least 50% thicker than its initial thickness, at least 100% thicker than its initial thickness, at least 300% thicker than its initial thickness, and at least 500% thicker than its initial thickness. As described above, in various circumstances, as a result of the above, the tissue thickness compensator can be configured to consume any gaps within the staple entrapment area. 
     As discussed above, in various embodiments, the tissue thickness compensator may comprise a hydrogel. In various embodiments, the hydrogel may comprise homopolymer hydrogels, copolymer hydrogels, multipolymer hydrogels, interpenetrating polymer hydrogels, and combinations thereof. In various embodiments, the hydrogel may comprise microgels, nanogels, and combinations thereof. The hydrogel may generally comprise a hydrophilic polymer network capable of absorbing and/or retaining fluids. In various embodiments, the hydrogel may comprise a non-crosslinked hydrogel, a crosslinked hydrogel, and combinations thereof. The hydrogel may comprise chemical crosslinks, physical crosslinks, hydrophobic segments and/or water insoluble segments. The hydrogel may be chemically crosslinked by polymerization, small-molecule crosslinking, and/or polymer-polymer crosslinking. The hydrogel may be physically crosslinked by ionic interactions, hydrophobic interactions, hydrogen bonding interactions, sterocomplexation, and/or supramolecular chemistry. The hydrogel may be substantially insoluble due to the crosslinks, hydrophobic segments and/or water insoluble segments, but be expandable and/or swellable due to absorbing and/or retaining fluids. In certain embodiments, the precursor may crosslink with endogenous materials and/or tissues. 
     In various embodiments, the hydrogel may comprise an environmentally sensitive hydrogel (ESH). The ESH may comprise materials having fluid-swelling properties that relate to environmental conditions. The environmental conditions may include, but are not limited to, the physical conditions, biological conditions, and/or chemical conditions at the surgical site. In various embodiments, the hydrogel may swell or shrink in response to temperature, pH, electric fields, ionic strength, enzymatic and/or chemical reactions, electrical and/or magnetic stimuli, and other physiological and environmental variables, for example. In various embodiments, the ESH may comprise multifunctional acrylates, hydroxyethylmethacrylate (HEMA), elastomeric acrylates, and related monomers. 
     In various embodiments, the tissue thickness compensator comprising a hydrogel may comprise at least one of the non-synthetic materials and synthetic materials described above. The hydrogel may comprise a synthetic hydrogel and/or a non-synthetic hydrogel. In various embodiments, the tissue thickness compensator may comprise a plurality of layers. The plurality of the layers may comprise porous layers and/or non-porous layers. For example, the tissue thickness compensator may comprise a non-porous layer and a porous layer. In another example, the tissue thickness compensator may comprise a porous layer intermediate a first non-porous layer and a second non-porous layer. In another example, the tissue thickness compensator may comprise a non-porous layer intermediate a first porous layer and a second porous layer. The non-porous layers and porous layers may be positioned in any order relative to the surfaces of the staple cartridge and/or anvil. 
     Examples of the non-synthetic material may include, but are not limited to, albumin, alginate, carbohydrate, casein, cellulose, chitin, chitosan, collagen, blood, dextran, elastin, fibrin, fibrinogen, gelatin, heparin, hyaluronic acid, keratin, protein, serum, and starch. The cellulose may comprise hydroxyethyl cellulose, oxidized cellulose, oxidized regenerated cellulose (ORC), hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethylcellulose, and combinations thereof. The collagen may comprise bovine pericardium. The carbohydrate may comprise a polysaccharide, such as lyophilized polysaccharide. The protein may comprise glycoprotein, proteoglycan, and combinations thereof. 
     Examples of the synthetic material may include, but are not limited to, poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(phosphazine), polyesters, polyethylene glycols, polyethylene oxide, polyethylene oxide-co-polypropylene oxide, co-polyethylene oxide, polyalkyleneoxides, polyacrylamides, polyhydroxyethylmethylacrylate, poly(vinylpyrrolidone), polyvinyl alcohols, poly(caprolactone), poly(dioxanone), polyacrylic acid, polyacetate, polypropylene, aliphatic polyesters, glycerols, poly(amino acids), copoly(ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyoxaesters, polyorthoesters, polyphosphazenes and combinations thereof. In certain embodiments, the above non-synthetic materials may be synthetically prepared, e.g., synthetic hyaluronic acid, utilizing conventional methods. 
     In various embodiments, the hydrogel may be made from one or more hydrogel precursors. The precursor may comprise a monomer and/or a macromer. The hydrogel precursor may comprise an electrophile functional group and/or a nucleophile electrophile functional group. In general, electrophiles may react with nucleophiles to form a bond. The term “functional group” as used herein refers to electrophilic or nucleophilic groups capable of reacting with each other to form a bond. Examples of electrophilic functional groups may include, but are not limited to, N-hydroxysuccinimides (“NHS”), sulfosuccinimides, carbonyldiimidazole, sulfonyl chloride, aryl halides, sulfosuccinimidyl esters, N-hydroxysuccinimidyl esters, succinimidyl esters such as succinimidyl succinates and/or succinimidyl propionates, isocyanates, thiocyanates, carbodiimides, benzotriazole carbonates, epoxides, aldehydes, maleimides, imidoesters, combinations thereof, and the like. In at least one embodiment, the electrophilic functional group may comprise a succinimidyl ester. Examples of nucleophile functional groups may include, but are not limited to, —NH 2 , —SH, —OH, —PH 2 , and —CO—NH—NH 2 . 
     In various embodiments, the hydrogel may be formed from a single precursor or multiple precursors. In certain embodiments, the hydrogel may be formed from a first precursor and a second precursor. The first hydrogel precursor and second hydrogel precursor may form a hydrogel in situ and/or in vivo upon contact. The hydrogel precursor may generally refer to a polymer, functional group, macromolecule, small molecule, and/or crosslinker that can take part in a reaction to form a hydrogel. The precursor may comprise a homogeneous solution, heterogeneous, or phase separated solution in a suitable solvent, such as water or a buffer, for example. The buffer may have a pH from about 8 to about 12, such as, about 8.2 to about 9, for example. Examples of buffers may include, but are not limited to borate buffers. In certain embodiments, the precursor(s) may be in an emulsion. In various embodiments, a first precursor may react with a second precursor to form a hydrogel. In various embodiments, the first precursor may spontaneously crosslink when contacted with the second precursor. In various embodiments, a first set of electrophilic functional groups on a first precursor may react with a second set of nucleophilic functional groups on a second precursor. When the precursors are mixed in an environment that permits reaction (e.g., as relating to pH, temperature, and/or solvent), the functional groups may react with each other to form covalent bonds. The precursors may become crosslinked when at least some of the precursors react with more than one other precursor. 
     In various embodiments, the tissue thickness compensator may comprise at least one monomer selected from the group consisting of 3-sulfopropyl acrylate potassium salt (“KSPA”), sodium acrylate (“NaA”), N-(tris(hydroxylmethyl)methyl)acrylamide (“tris acryl”), and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS). The tissue thickness compensator may comprise a copolymer comprising two or more monomers selected from the group consisting of KSPA, NaA, tris acryl, AMPS. The tissue thickness compensator may comprise homopolymers derived from KSPA, NaA, trisacryl and AMPS. The tissue thickness compensator may comprise hydrophilicity modifying monomers copolymerizable therewith. The hydrophilicity modifying monomers may comprise methylmethacrylate, butylacrylate, cyclohexylacrylate, styrene, styrene sulphonic acid. 
     In various embodiments, the tissue thickness compensator may comprise a crosslinker. The crosslinker may comprise a low molecular weight di- or polyvinylic crosslinking agent, such as ethylenglycol diacrylate or dimethacrylate, di-, tri- or tetraethylen-glycol diacrylate or dimethacrylate, allyl(meth)acrylate, a C 2 -C 8 -alkylene diacrylate or dimethacrylate, divinyl ether, divinyl sulfone, di- and trivinylbenzene, trimethylolpropane triacrylate or trimethacrylate, pentaerythritol tetraacrylate or tetramethacrylate, bisphenol A diacrylate or dimethacrylate, methylene bisacrylamide or bismethacrylamide, ethylene bisacrylamide or ethylene bismethacrylamide, triallyl phthalate or diallyl phthalate. In at least one embodiment, the crosslinker may comprise N,N′-methylenebisacrylamide (“MBAA”). 
     In various embodiments, the tissue thickness compensator may comprise at least one of acrylate and/or methacrylate functional hydrogels, biocompatible photoinitiator, alkyl-cyanoacrylates, isocyanate functional macromers, optionally comprising amine functional macromers, succinimidyl ester functional macromers, optionally comprising amine and/or sulfhydryl functional macromers, epoxy functional macromers, optionally comprising amine functional macromers, mixtures of proteins and/or polypeptides and aldehyde crosslinkers, Genipin, and water-soluble carbodiimides, anionic polysaccharides and polyvalent cations. 
     In various embodiments, the tissue thickness compensator may comprise unsaturated organic acid monomers, acrylic substituted alcohols, and/or acrylamides. In various embodiments, the tissue thickness compensator may comprise methacrylic acids, acrylic acids, glycerolacrylate, glycerolmethacryulate, 2-hydroxyethylmethacrylate, 2-hydroxyethylacrylate, 2-(dimethylaminoethyl)methacrylate, N-vinyl pyrrolidone, methacrylamide, and/or N,N-dimethylacrylamide poly(methacrylic acid). 
     In various embodiments, the tissue thickness compensator may comprise a reinforcement material. In various embodiments, the reinforcement material may comprise at least one of the non-synthetic materials and synthetic materials described above. In various embodiments, the reinforcement material may comprise collagen, gelatin, fibrin, fibrinogen, elastin, keratin, albumin, hydroxyethyl cellulose, cellulose, oxidized cellulose, hydroxypropyl cellulose, carboxyethyl cellulose, carboxymethylcellulose, chitan, chitosan, alginate, poly(lactic acid), poly(glycolic acid), poly(hydroxybutyrate), poly(phosphazine), polyesters, polyethylene glycols, polyalkyleneoxides, polyacrylamides, polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinyl alcohols, poly(caprolactone), poly(dioxanone), polyacrylic acid, polyacetate, polycaprolactone, polypropylene, aliphatic polyesters, glycerols, poly(amino acids), copoly(ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyalkylene oxalates, polyoxaesters, polyorthoesters, polyphosphazenes and combinations thereof. 
     In various embodiments, the tissue thickness compensator may comprise a layer comprising the reinforcement material. In certain embodiments, a porous layer and/or a non-porous layer of a tissue thickness compensator may comprise the reinforcement material. For example, the porous layer may comprise the reinforcement material and the non-porous layer may not comprise the reinforcement material. In various embodiments, the reinforcement layer may comprise an inner layer intermediate a first non-porous layer and a second non-porous layer. In certain embodiments, the reinforcement layer may comprise an outer layer of the tissue thickness compensator. In certain embodiments, the reinforcement layer may comprise an exterior surface of the tissue thickness compensator. 
     In various embodiments, the reinforcement material may comprise meshes, monofilaments, multifilament braids, fibers, mats, felts, particles, and/or powders. In certain embodiments, the reinforcement material may be incorporated into a layer of the tissue thickness compensator. The reinforcement material may be incorporated into at least one of a non-porous layer and a porous layer. A mesh comprising the reinforcement material may be formed using conventional techniques, such as, for example, knitting, weaving, tatting, and/or knipling. In various embodiments, a plurality of reinforcement materials may be oriented in a random direction and/or a common direction. In certain embodiments, the common direction may be one of parallel to the staple line and perpendicular to the staple line, for example. For example, the monofilaments and/or multifilament braids may be oriented in a random direction and/or a common direction. The monofilaments and multifilament braids may be associated with the non-porous layer and/or the porous layer. In various embodiments, the tissue thickness compensator may comprise a plurality of reinforcement fibers oriented in a random direction within a non-porous layer. In various embodiments, the tissue thickness compensator may comprise a plurality of reinforcement fibers oriented in a common direction within a non-porous layer. 
     The fibers may form a non-woven material, such as, for example, a mat and a felt. The fibers may have any suitable length, such as, for example from 0.1 mm to 100 mm and 0.4 mm to 50 mm. The reinforcement material may be ground to a powder. The powder may have a particle size from 10 micrometers to 1 cm, for example. The powder may be incorporated into the tissue thickness compensator. 
     In various embodiments, the tissue thickness compensator may be formed in situ. In various embodiments, the hydrogel may be formed in situ. The tissue thickness compensator may be formed in situ by covalent, ionic, and/or hydrophobic bonds. Physical (non-covalent) crosslinks may result from complexation, hydrogen bonding, desolvation, Van der Waals interactions, ionic bonding, and combinations thereof. Chemical (covalent) crosslinking may be accomplished by any of a number of mechanisms, including: free radical polymerization, condensation polymerization, anionic or cationic polymerization, step growth polymerization, electrophile-nucleophile reactions, and combinations thereof. 
     In various embodiments, in situ formation of the tissue thickness compensator may comprise reacting two or more precursors that are physically separated until contacted in situ and/or react to an environmental condition to react with each other to form the hydrogel. In situ polymerizable polymers may be prepared from precursor(s) that can be reacted to form a polymer at the surgical site. The tissue thickness compensator may be formed by crosslinking reactions of the precursor(s) in situ. In certain embodiments, the precursor may comprise an initiator capable of initiating a polymerization reaction for the formation of the in situ tissue thickness compensator. The tissue thickness compensator may comprise a precursor that can be activated at the time of application to create, in various embodiments, a crosslinked hydrogel. In situ formation of the tissue thickness compensator may comprise activating at least one precursor to form bonds to form the tissue thickness compensator. In various embodiments, activation may be achieved by changes in the physical conditions, biological conditions, and/or chemical conditions at the surgical site, including, but not limited to temperature, pH, electric fields, ionic strength, enzymatic and/or chemical reactions, electrical and/or magnetic stimuli, and other physiological and environmental variables. In various embodiments, the precursors may be contacted outside the body and introduced to the surgical site. 
     In various embodiments, the tissue thickness compensator may comprise one or more encapsulations, or cells, which can be configured to store at least one component therein. In certain embodiments, the encapsulation may be configured to store a hydrogel precursor therein. In certain embodiments, the encapsulation may be configured to store two components therein, for example. In certain embodiments, the encapsulation may be configured to store a first hydrogel precursor and a second hydrogel precursor therein. In certain embodiments, a first encapsulation may be configured to store a first hydrogel precursor therein and a second encapsulation may be configured to store a second hydrogel precursor therein. As described above, the encapsulations can be aligned, or at least substantially aligned, with the staple legs to puncture and/or otherwise rupture the encapsulations when the staple legs contact the encapsulation. In certain embodiments, the encapsulations may be compressed, crushed, collapsed, and/or otherwise ruptured when the staples are deployed. After the encapsulations have been ruptured, the component(s) stored therein can flow out of the encapsulation. The component stored therein may contact other components, layers of the tissue thickness compensator, and/or the tissue. In various embodiments, the other components may be flowing from the same or different encapsulations, provided in the layers of the tissue thickness compensator, and/or provided to the surgical site by the clinician. As a result of the above, the component(s) stored within the encapsulations can provide expansion and/or swelling of the tissue thickness compensator. 
     In various embodiments, the tissue thickness compensator may comprise a layer comprising the encapsulations. In various embodiments, the encapsulation may comprise a void, a pocket, a dome, a tube, and combinations thereof associated with the layer. In certain embodiments, the encapsulations may comprise voids in the layer. In at least one embodiment, the layer can comprise two layers that can be attached to one another wherein the encapsulations can be defined between the two layers. In certain embodiments, the encapsulations may comprise domes on the surface of the layer. For example, at least a portion of the encapsulations can be positioned within domes extending upwardly from the layer. In certain embodiments, the encapsulations may comprise pockets formed within the layer. In certain embodiments, a first portion of the encapsulations may comprise a dome and a second portion of the encapsulations may comprise a pocket. In certain embodiments, the encapsulations may comprise a tube embedded within the layer. In certain embodiments, the tube may comprise the non-synthetic materials and/or synthetic materials described herein, such as PLA. In at least one embodiment, the tissue thickness compensator may comprise a bioabsorable foam, such as ORC, comprising PLA tubes embedded therein, and the tube may encapsulate a hydrogel, for example. In certain embodiments, the encapsulations may comprise discrete cells that are unconnected to each other. In certain embodiments, one or more of the encapsulations can be in fluid communication with each other via one or more passageways, conduits, and/or channels, for example, extending through the layer. 
     The rate of release of a component from the encapsulation may be controlled by the thickness of the tissue thickness compensator, the composition of tissue thickness compensator, the size of the component, the hydrophilicity of the component, and/or the physical and/or chemical interactions among the component, the composition of the tissue thickness compensator, and/or the surgical instrument, for example. In various embodiments, the layer can comprise one or more thin sections or weakened portions, such as partial perforations, for example, which can facilitate the incision of the layer and the rupture of the encapsulations. In various embodiments, the partial perforations may not completely extend through a layer while, in certain embodiments, perforations may completely extend through the layer. 
     In various embodiments, an anvil may comprise a tissue thickness compensator comprising an encapsulated component comprising at least one microsphere particle. In certain embodiments, the tissue thickness compensator may comprise an encapsulation comprising a first encapsulated component and a second encapsulated component. In certain embodiments, the tissue thickness compensator may comprise an encapsulation comprising a first microsphere particle and a second microsphere particle. 
     In various embodiments, the tissue thickness compensator may be suitable for use with a surgical instrument. As described above the tissue thickness compensator may be associated with the staple cartridge and/or the anvil. The tissue thickness compensator may be configured into any shape, size and/or dimension suitable to fit the staple cartridge and/or anvil. As described herein, the tissue thickness compensator may be releasably attached to the staple cartridge and/or anvil. The tissue thickness compensator may be attached to the staple cartridge and/or anvil in any mechanical and/or chemical manner capable of retaining the tissue thickness compensator in contact with the staple cartridge and/or anvil prior to and during the stapling process. The tissue thickness compensator may be removed or released from the staple cartridge and/or anvil after the staple penetrates the tissue thickness compensator. The tissue thickness compensator may be removed or released from the staple cartridge and/or anvil as the staple cartridge and/or anvil is moved away from the tissue thickness compensator. 
     In various embodiments, referring now to  FIG. 14 , a staple cartridge, such as staple cartridge  10000 , for example, can comprise a support portion  10010  and a compressible tissue thickness compensator  10020 . Referring now to  FIGS. 16-18 , the support portion  10010  can comprise a deck surface  10011  and a plurality of staple cavities  10012  defined within the support portion  10010 . Each staple cavity  10012  can be sized and configured to removably store a staple, such as a staple  10030 , for example, therein. The staple cartridge  10000  can further comprise a plurality of staple drivers  10040  which can each be configured to support one or more staples  10030  within the staple cavities  10012  when the staples  10030  and the staple drivers  10040  are in their unfired positions. In at least one such embodiment, referring primarily to  FIGS. 22 and 23 , each staple driver  10040  can comprise one or more cradles, or troughs,  10041 , for example, which can be configured to support the staples and limit relative movement between the staples  10030  and the staple drivers  10040 . In various embodiments, referring again to  FIG. 16 , the staple cartridge  10000  can further comprise a staple-firing sled  10050  which can be moved from a proximal end  10001  to a distal end  10002  of the staple cartridge in order to sequentially lift the staple drivers  10040  and the staples  10030  from their unfired positions toward an anvil positioned opposite the staple cartridge  10000 . In certain embodiments, referring primarily to  FIGS. 16 and 18 , each staple  10030  can comprise a base  10031  and one or more legs  10032  extending from the base  10031  wherein each staple can be at least one of substantially U-shaped and substantially V-shaped, for example. In at least one embodiment, the staples  10030  can be configured such that the tips of the staple legs  10032  are recessed with respect to the deck surface  10011  of the support portion  10010  when the staples  10030  are in their unfired positions. In at least one embodiment, the staples  10030  can be configured such that the tips of the staple legs  10032  are flush with respect to the deck surface  10011  of the support portion  10010  when the staples  10030  are in their unfired positions. In at least one embodiment, the staples  10030  can be configured such that the tips of the staple legs  10032 , or at least some portion of the staple legs  10032 , extend above the deck surface  10011  of the support portion  10010  when the staples  10030  are in their unfired positions. In such embodiments, the staple legs  10032  can extend into and can be embedded within the tissue thickness compensator  10020  when the staples  10030  are in their unfired positions. In at least one such embodiment, the staple legs  10032  can extend above the deck surface  10011  by approximately 0.075″, for example. In various embodiments, the staple legs  10032  can extend above the deck surface  10011  by a distance between approximately 0.025″ and approximately 0.125″, for example. In certain embodiments, further to the above, the tissue thickness compensator  10020  can comprise an uncompressed thickness between approximately 0.08″ and approximately 0.125″, for example. 
     In use, further to the above and referring primarily to  FIG. 31 , an anvil, such as anvil,  10060 , for example, can be moved into a closed position opposite the staple cartridge  10000 . As described in greater detail below, the anvil  10060  can position tissue against the tissue thickness compensator  10020  and, in various embodiments, compress the tissue thickness compensator  10020  against the deck surface  10011  of the support portion  10010 , for example. Once the anvil  10060  has been suitably positioned, the staples  10030  can be deployed, as also illustrated in  FIG. 31 . In various embodiments, as mentioned above, the staple-firing sled  10050  can be moved from the proximal end  10001  of the staple cartridge  10000  toward the distal end  10002 , as illustrated in  FIG. 32 . As the sled  10050  is advanced, the sled  10050  can contact the staple drivers  10040  and lift the staple drivers  10040  upwardly within the staple cavities  10012 . In at least one embodiment, the sled  10050  and the staple drivers  10040  can each comprise one or more ramps, or inclined surfaces, which can co-operate to move the staple drivers  10040  upwardly from their unfired positions. In at least one such embodiment, referring to  FIGS. 19-23 , each staple driver  10040  can comprise at least one inclined surface  10042  and the sled  10050  can comprise one or more inclined surfaces  10052  which can be configured such that the inclined surfaces  10052  can slide under the inclined surface  10042  as the sled  10050  is advanced distally within the staple cartridge. As the staple drivers  10040  are lifted upwardly within their respective staple cavities  10012 , the staple drivers  10040  can lift the staples  10030  upwardly such that the staples  10030  can emerge from their staple cavities  10012  through openings in the staple deck  10011 . During an exemplary firing sequence, referring primarily to  FIGS. 25-27 , the sled  10050  can first contact staple  10030   a  and begin to lift the staple  10030   a  upwardly. As the sled  10050  is advanced further distally, the sled  10050  can begin to lift staples  10030   b ,  10030   c ,  10030   d ,  10030   e , and  10030   f , and any other subsequent staples, in a sequential order. As illustrated in  FIG. 27 , the sled  10050  can drive the staples  10030  upwardly such that the legs  10032  of the staples contact the opposing anvil, are deformed to a desired shape, and ejected therefrom the support portion  10010 . In various circumstances, the sled  10030  can move several staples upwardly at the same time as part of a firing sequence. With regard to the firing sequence illustrated in  FIG. 27 , the staples  10030   a  and  10030   b  have been moved into their fully fired positions and ejected from the support portion  10010 , the staples  10030   c  and  10030   d  are in the process of being fired and are at least partially contained within the support portion  10010 , and the staples  10030   e  and  10030   f  are still in their unfired positions. 
     As discussed above, and referring to  FIG. 33 , the staple legs  10032  of the staples  10030  can extend above the deck surface  10011  of the support portion  10010  when the staples  10030  are in their unfired positions. With further regard to this firing sequence illustrated in  FIG. 27 , the staples  10030   e  and  10030   f  are illustrated in their unfired position and their staple legs  10032  extend above the deck surface  10011  and into the tissue thickness compensator  10020 . In various embodiments, the tips of the staple legs  10032 , or any other portion of the staple legs  10032 , may not protrude through a top tissue-contacting surface  10021  of the tissue thickness compensator  10020  when the staples  10030  are in their unfired positions. As the staples  10030  are moved from their unfired positions to their fired positions, as illustrated in  FIG. 27 , the tips of the staple legs can protrude through the tissue-contacting surface  10032 . In various embodiments, the tips of the staple legs  10032  can comprise sharp tips which can incise and penetrate the tissue thickness compensator  10020 . In certain embodiments, the tissue thickness compensator  10020  can comprise a plurality of apertures which can be configured to receive the staple legs  10032  and allow the staple legs  10032  to slide relative to the tissue thickness compensator  10020 . In certain embodiments, the support portion  10010  can further comprise a plurality of guides  10013  extending from the deck surface  10011 . The guides  10013  can be positioned adjacent to the staple cavity openings in the deck surface  10011  such that the staple legs  10032  can be at least partially supported by the guides  10013 . In certain embodiments, a guide  10013  can be positioned at a proximal end and/or a distal end of a staple cavity opening. In various embodiments, a first guide  10013  can be positioned at a first end of each staple cavity opening and a second guide  10013  can be positioned at a second end of each staple cavity opening such that each first guide  10013  can support a first staple leg  10032  of a staple  10030  and each second guide  10013  can support a second staple leg  10032  of the staple. In at least one embodiment, referring to  FIG. 33 , each guide  10013  can comprise a groove or slot, such as groove  10016 , for example, within which a staple leg  10032  can be slidably received. In various embodiments, each guide  10013  can comprise a cleat, protrusion, and/or spike that can extend from the deck surface  10011  and can extend into the tissue thickness compensator  10020 . In at least one embodiment, as discussed in greater detail below, the cleats, protrusions, and/or spikes can reduce relative movement between the tissue thickness compensator  10020  and the support portion  10010 . In certain embodiments, the tips of the staple legs  10032  may be positioned within the guides  10013  and may not extend above the top surfaces of the guides  10013  when the staples  10030  are in their unfired position. In at least such embodiment, the guides  10013  can define a guide height and the staples  10030  may not extend above this guide height when they are in their unfired position. 
     In various embodiments, a tissue thickness compensator, such as tissue thickness compensator  10020 , for example, can be comprised of a single sheet of material. In at least one embodiment, a tissue thickness compensator can comprise a continuous sheet of material which can cover the entire top deck surface  10011  of the support portion  10010  or, alternatively, cover less than the entire deck surface  10011 . In certain embodiments, the sheet of material can cover the staple cavity openings in the support portion  10010  while, in other embodiments, the sheet of material can comprise openings which can be aligned, or at least partially aligned, with the staple cavity openings. In various embodiments, a tissue thickness compensator can be comprised of multiple layers of material. In some embodiments, referring now to  FIG. 15 , a tissue thickness compensator can comprise a compressible core and a wrap surrounding the compressible core. In certain embodiments, a wrap  10022  can be configured to releasably hold the compressible core to the support portion  10010 . In at least one such embodiment, the support portion  10010  can comprise one or more projections, such as projections  10014  ( FIG. 18 ), for example, extending therefrom which can be received within one or more apertures and/or slots, such as apertures  10024 , for example, defined in the wrap  10022 . The projections  10014  and the apertures  10024  can be configured such that the projections  10014  can retain the wrap  10022  to the support portion  10010 . In at least one embodiment, the ends of the projections  10014  can be deformed, such as by a heat-stake process, for example, in order to enlarge the ends of the projections  10014  and, as a result, limit the relative movement between the wrap  10022  and the support portion  10010 . In at least one embodiment, the wrap  10022  can comprise one or more perforations  10025  which can facilitate the release of the wrap  10022  from the support portion  10010 , as illustrated in  FIG. 15 . Referring now to  FIG. 24 , a tissue thickness compensator can comprise a wrap  10222  including a plurality of apertures  10223 , wherein the apertures  10223  can be aligned, or at least partially aligned, with the staple cavity openings in the support portion  10010 . In certain embodiments, the core of the tissue thickness compensator can also comprise apertures which are aligned, or at least partially aligned, with the apertures  10223  in the wrap  10222 . In other embodiments, the core of the tissue thickness compensator can comprise a continuous body and can extend underneath the apertures  10223  such that the continuous body covers the staple cavity openings in the deck surface  10011 . 
     In various embodiments, as described above, a tissue thickness compensator can comprise a wrap for releasably holding a compressible core to the support portion  10010 . In at least one such embodiment, referring to  FIG. 16 , a staple cartridge can further comprise retainer clips  10026  which can be configured to inhibit the wrap, and the compressible core, from prematurely detaching from the support portion  10010 . In various embodiments, each retainer clip  10026  can comprise apertures  10028  which can be configured to receive the projections  10014  extending from the support portion  10010  such that the retainer clips  10026  can be retained to the support portion  10010 . In certain embodiments, the retainer clips  10026  can each comprise at least one pan portion  10027  which can extend underneath the support portion  10010  and can support and retain the staple drivers  10040  within the support portion  10010 . In certain embodiments, as described above, a tissue thickness compensator can be removably attached to the support portion  10010  by the staples  10030 . More particularly, as also described above, the legs of the staples  10030  can extend into the tissue thickness compensator  10020  when the staples  10030  are in their unfired position and, as a result, releasably hold the tissue thickness compensator  10020  to the support portion  10010 . In at least one embodiment, the legs of the staples  10030  can be in contact with the sidewalls of their respective staple cavities  10012  wherein, owing to friction between the staple legs  10032  and the sidewalls, the staples  10030  and the tissue thickness compensator  10020  can be retained in position until the staples  10030  are deployed from the staple cartridge  10000 . When the staples  10030  are deployed, the tissue thickness compensator  10020  can be captured within the staples  10030  and held against the stapled tissue T. When the anvil is thereafter moved into an open position to release the tissue T, the support portion  10010  can be moved away from the tissue thickness compensator  10020  which has been fastened to the tissue. In certain embodiments, an adhesive can be utilized to removably hold the tissue thickness compensator  10020  to the support portion  10010 . In at least one embodiment, a two-part adhesive can be utilized wherein, in at least one embodiment, a first part of the adhesive can be placed on the deck surface  10011  and a second part of the adhesive can be placed on the tissue thickness compensator  10020  such that, when the tissue thickness compensator  10020  is placed against the deck surface  10011 , the first part can contact the second part to active the adhesive and detachably bond the tissue thickness compensator  10020  to the support portion  10010 . In various embodiments, any other suitable means could be used to detachably retain the tissue thickness compensator to the support portion of a staple cartridge. 
     In various embodiments, further to the above, the sled  10050  can be advanced from the proximal end  10001  to the distal end  10002  to fully deploy all of the staples  10030  contained within the staple cartridge  10000 . In at least one embodiment, referring now to  FIGS. 56-60 , the sled  10050  can be advanced distally within a longitudinal cavity  10016  within the support portion  10010  by a firing member, or knife bar,  10052  of a surgical stapler. In use, the staple cartridge  10000  can be inserted into a staple cartridge channel in a jaw of the surgical stapler, such as staple cartridge channel  10070 , for example, and the firing member  10052  can be advanced into contact with the sled  10050 , as illustrated in  FIG. 56 . As the sled  10050  is advanced distally by the firing member  10052 , the sled  10050  can contact the proximal-most staple driver, or drivers,  10040  and fire, or eject, the staples  10030  from the cartridge body  10010 , as described above. As illustrated in  FIG. 56 , the firing member  10052  can further comprise a cutting edge  10053  which can be advanced distally through a knife slot in the support portion  10010  as the staples  10030  are being fired. In various embodiments, a corresponding knife slot can extend through the anvil positioned opposite the staple cartridge  10000  such that, in at least one embodiment, the cutting edge  10053  can extend between the anvil and the support portion  10010  and incise the tissue and the tissue thickness compensator positioned therebetween. In various circumstances, the sled  10050  can be advanced distally by the firing member  10052  until the sled  10050  reaches the distal end  10002  of the staple cartridge  10000 , as illustrated in  FIG. 58 . At such point, the firing member  10052  can be retracted proximally. In some embodiments, the sled  10050  can be retracted proximally with the firing member  10052  but, in various embodiments, referring now to  FIG. 59 , the sled  10050  can be left behind in the distal end  10002  of the staple cartridge  10000  when the firing member  10052  is retracted. Once the firing member  10052  has been sufficiently retracted, the anvil can be re-opened, the tissue thickness compensator  10020  can be detached from the support portion  10010 , and the remaining non-implanted portion of the expended staple cartridge  10000 , including the support portion  10010 , can be removed from the staple cartridge channel  10070 . 
     After the expended staple cartridge  10000  has been removed from the staple cartridge channel, further to the above, a new staple cartridge  10000 , or any other suitable staple cartridge, can be inserted into the staple cartridge channel  10070 . In various embodiments, further to the above, the staple cartridge channel  10070 , the firing member  10052 , and/or the staple cartridge  10000  can comprise co-operating features which can prevent the firing member  10052  from being advanced distally a second, or subsequent, time without a new, or unfired, staple cartridge  10000  positioned in the staple cartridge channel  10070 . More particularly, referring again to  FIG. 56 , as the firing member  10052  is advanced into contact with the sled  10050  and, when the sled  10050  is in its proximal unfired position, a support nose  10055  of the firing member  10052  can be positioned on and/or over a support ledge  10056  on the sled  10050  such that the firing member  10052  is held in a sufficient upward position to prevent a lock, or beam,  10054  extending from the firing member  10052  from dropping into a lock recess defined within the staple cartridge channel. As the lock  10054  will not drop into the lock recess, in such circumstances, the lock  10054  may not abut a distal sidewall  10057  of the lock recess as the firing member  10052  is advanced. As the firing member  10052  pushes the sled  10050  distally, the firing member  10052  can be supported in its upward firing position owing to the support nose  10055  resting on the support ledge  10056 . When the firing member  10052  is retracted relative to the sled  10050 , as discussed above and illustrated in  FIG. 59 , the firing member  10052  can drop downwardly from its upward position as the support nose  10055  is no longer resting on the support ledge  10056  of the sled  10050 . In at least one such embodiment, the surgical staple can comprise a spring  10058 , and/or any other suitable biasing element, which can be configured to bias the firing member  10052  into its downward position. Once the firing member  10052  has been completely retracted, as illustrated in  FIG. 60 , the firing member  10052  cannot be advanced distally through the spent staple cartridge  10000  once again. More particularly, the firing member  10052  can&#39;t be held in its upper position by the sled  10050  as the sled  10050 , at this point in the operating sequence, has been left behind at the distal end  10002  of the staple cartridge  10000 . Thus, as mentioned above, in the event that the firing member  10052  is advanced once again without replacing the staple cartridge, the lock beam  10054  will contact the sidewall  10057  of the lock recess which will prevent the firing member  10052  from being advanced distally into the staple cartridge  10000  once again. Stated another way, once the spent staple cartridge  10000  has been replaced with a new staple cartridge, the new staple cartridge will have a proximally-positioned sled  10050  which can hold the firing member  10052  in its upper position and allow the firing member  10052  to be advanced distally once again. 
     As described above, the sled  10050  can be configured to move the staple drivers  10040  between a first, unfired position and a second, fired position in order to eject staples  10030  from the support portion  10010 . In various embodiments, the staple drivers  10040  can be contained within the staple cavities  10012  after the staples  10030  have been ejected from the support portion  10010 . In certain embodiments, the support portion  10010  can comprise one or more retention features which can be configured to block the staple drivers  10040  from being ejected from, or falling out of, the staple cavities  10012 . In various other embodiments, the sled  10050  can be configured to eject the staple drivers  10040  from the support portion  10010  with the staples  10030 . In at least one such embodiment, the staple drivers  10040  can be comprised of a bioabsorbable and/or biocompatible material, such as Ultem, for example. In certain embodiments, the staple drivers can be attached to the staples  10030 . In at least one such embodiment, a staple driver can be molded over and/or around the base of each staple  10030  such that the driver is integrally formed with the staple. U.S. patent application Ser. No. 11/541,123, entitled SURGICAL STAPLES HAVING COMPRESSIBLE OR CRUSHABLE MEMBERS FOR SECURING TISSUE THEREIN AND STAPLING INSTRUMENTS FOR DEPLOYING THE SAME, filed on Sep. 29, 2006, now U.S. Pat. No. 7,794,475, which issued on Sep. 14, 2010, is hereby incorporated by reference in its entirety. 
     As described above, a surgical stapling instrument can comprise a staple cartridge channel configured to receive a staple cartridge, an anvil rotatably coupled to the staple cartridge channel, and a firing member comprising a knife edge which is movable relative to the anvil and the staple cartridge channel. In use, a staple cartridge can be positioned within the staple cartridge channel and, after the staple cartridge has been at least partially expended, the staple cartridge can be removed from the staple cartridge channel and replaced with a new staple cartridge. In some such embodiments, the staple cartridge channel, the anvil, and/or the firing member of the surgical stapling instrument may be re-used with the replacement staple cartridge. In certain other embodiments, a staple cartridge may comprise a part of a disposable loading unit assembly which can include a staple cartridge channel, an anvil, and/or a firing member, for example, which can be replaced along with the staple cartridge as part of replacing the disposable loading unit assembly. Certain disposable loading unit assemblies are disclosed in U.S. patent application Ser. No. 12/031,817, entitled END EFFECTOR COUPLING ARRANGEMENTS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT, which was filed on Feb. 15, 2008, the entire disclosure of which is incorporated by reference herein. 
     In various embodiments, the tissue thickness compensator may comprise an extrudable, a castable, and/or moldable composition comprising at least one of the synthetic and/or non-synthetic materials described herein. In various embodiments, the tissue thickness compensator may comprise a film or sheet comprising two or more layers. The tissue thickness compensator may be obtained using conventional methods, such as, for example, mixing, blending, compounding, spraying, wicking, solvent evaporating, dipping, brushing, vapor deposition, extruding, calendaring, casting, molding and the like. In extrusion, an opening may be in the form of a die comprising at least one opening to impart a shape to the emerging extrudate. In calendering, an opening may comprise a nip between two rolls. Conventional molding methods may include, but are not limited to, blow molding, injection molding, foam injection, compression molding, thermoforming, extrusion, foam extrusion, film blowing, calendaring, spinning, solvent welding, coating methods, such as dip coating and spin coating, solution casting and film casting, plastisol processing (including knife coating, roller coating and casting), and combinations thereof. In injection molding, an opening may comprise a nozzle and/or channels/runners and/or mold cavities and features. In compression molding, the composition may be positioned in a mold cavity, heated to a suitable temperature, and shaped by exposure to compression under relatively high pressure. In casting, the composition may comprise a liquid or slurry that may be poured or otherwise provided into, onto and/or around a mold or object to replicate features of the mold or object. After casting, the composition may be dried, cooled, and/or cured to form a solid. 
     In various embodiments, a method of manufacturing a tissue thickness compensator comprising at least one medicament stored and/or absorbed therein may generally comprise providing a tissue thickness compensator and contacting the tissue thickness compensator and the medicament to retain the medicament in the tissue thickness compensator. In at least one embodiment, a method of manufacturing a tissue thickness compensator comprising an antibacterial material may comprise providing a hydrogel, drying the hydrogel, swelling the hydrogel in an aqueous solution of silver nitrate, contacting the hydrogel and a solution of sodium chloride to form the tissue thickness compensator having antibacterial properties. The tissue thickness compensator may comprise silver dispersed therein. 
     In various embodiments, referring now to  FIG. 71 , a tissue thickness compensator  21020  can comprise a compensator body  21022  and a plurality of capsules, or tubes,  21024  positioned therein. In at least one embodiment, each of the tubes  21024  can include a cavity  21026  defined therein which can include one or more medicaments therein. As described in greater detail below, the tissue thickness compensator  21020  can be manufactured by placing the tubes  21024  in a mold, for example, and forming the compensator body  21022  around the tubes  21024 . In certain embodiments, the one or medicaments can be placed in the tubes  21024  before the tubes  21024  are placed in the mold such that, after the compensator body  21022  has solidified, lyophilized, and/or cured, for example, the tubes  21024  can be encapsulated in the compensator body  21022 . In other embodiments, referring now to  FIG. 72 , a tissue thickness compensator  21120  can comprise a plurality of capsules, or tubes,  21124  positioned within a compensator body  21122  wherein one or more medicaments can be loaded into the tubes  21124  after the compensator body  21122  has been formed around the tubes  21124 . In at least one such embodiment, the tissue thickness compensator  21120  can comprise a port  21123  which can be in fluid communication with the tubes  21124  and can be configured to permit the one or medicaments to be injected into the tubes  21124  utilizing a syringe  21125 , for example. In some circumstances, a surgeon, or other clinician, can load the one or more medicaments into the tubes  21124  just before the tissue thickness compensator  21120  is inserted into the patient. Such embodiments may be especially useful when the tissue thickness compensator  21120  may be expected to, or required to, have a long storage duration, or shelf-life. 
     In various embodiments, referring now to  FIG. 73 , the compensator body  21022  of the tissue thickness compensator  21020  can be comprised of a bioabsorbable material, for example. In at least one embodiment, the compensator body  21022  can be comprised of any suitable material, such as PGA and/or PCL, for example. In certain embodiments, the tubes  21024  can be comprised of any suitable of a bioabsorbable material, for example. In at least one embodiment, the tubes  21024  can be comprised of any suitable material, such as hyaluronic acid, gelatin, PDS, and/or oxidized regenerated cellulose (ORC), for example. In at least one embodiment, the one or medicaments  21025  contained within the cavity  21026  can comprise a fluid, such as, doxycycline, for example. In at least one such embodiment, each of the tubes  21024  can be sealed such that the medicaments  21025  can be stored within the tubes  21024  until at least a portion of the tubes  21024  have been dissolved and/or bioabsorbed, for example. In use, referring now to  FIG. 74 , the tubes  21024  can be exposed to a bodily fluid, such as blood, for example, which can come into contact with and dissolve the tubes  21024 . In at least one embodiment, referring to  FIG. 75 , the bodily fluid can be expressed from tissue T when the tissue T and the tissue thickness compensator  21020  are compressed by an anvil  21060  and/or a plurality of staples  21030 , for example. In various embodiments, a bioabsorbable wrap can be utilized to enclose, or at least partially enclose, the compensator body  21022 . In at least one such embodiment, the wrap can be comprised of hyaluronic acid and/or ORC, for example. 
     In various embodiments, referring now to  FIG. 77 , a capsule, or tube,  21224  can comprise a plurality of layers  21224   a - 21224   d , for example. In at least one embodiment, each tube  21224  can comprise an outer, or first, layer  21224   a , a second layer  21224   b , a third layer  21224   c , and an inner layer  21224   d , for example. In various embodiments, the outer layer  21224   a  can be comprised of a haemostatic material, such as thrombin, for example. The second layer  21224   b  can be comprised of an anti-microbial and/or anti-biotic material, such as doxycycline and/or gentamicin, for example. The third layer  21224   c  can be comprised of an anti-inflammatory material, such as diclofenac and/or NSAIDSs, for example. The inner layer  21224   d  can be comprised of a healing influencing material, such as a powdered collageno synthetic material, for example. Referring again to  FIG. 77 , the tube  21224  can be structured and arranged such that the outer layer  21224   a  is dissolved, or at least substantially dissolved, before the second layer  21224   b  is dissolved, or at least partially dissolved. In various embodiments, referring to  FIG. 76 , the outer layer  21224   a  can begin dissolve as soon as it is exposed to a bodily fluid. This moment in time is indicated as time to. In certain embodiments, the outer layer  21224   a  can be completely dissolved over the course of minutes, hours, and/or days wherein the material comprising the outer layer  21224   a  can reach a maximum efficacy or concentration at a moment in time indicated as time t 1 . At some later moment in time, the outer layer  21224   a  can be completely, or at least substantially, dissolved by a moment in time indicated by time t 2 . 
     As the outer layer  21224   a  is being dissolved, the bodily fluid can reach the second layer  21224   b  and begin to at least partially dissolve the second layer  21224   b . Similar to the above, the second layer  21224   b  can be completely dissolved over the course of minutes, hours, and/or days wherein the material comprising the second layer  21224   b  can reach a maximum efficacy or concentration at a moment in time indicated as time t 3 . In various circumstances, a bodily fluid can pass through the outer layer  21224   a  to reach the second layer  21224   b  such that the outer layer  21224   a  and the second layer  21224   b  can begin to dissolve at the same, or at least substantially the same, time. In any event, the reader will note that the time t 1  in which the material comprising the outer layer  21224   a  reaches its maximum efficacy or concentration can occur before time t 3 . At some later moment in time, the second layer  21224   b  can be completely, or at least substantially, dissolved by a moment in time indicated by time t 5 . As the reader will also note, the time t 5  can occur after time t 2 . As the second layer  21224   b  is being dissolved, the bodily fluid can reach the third layer  21224   c  and begin to at least partially dissolve the third layer  21224   c . Similar to the above, the third layer  21224   c  can be completely dissolved over the course of minutes, hours, and/or days wherein the material comprising the third layer  21224   c  can reach a maximum efficacy or concentration at a moment in time indicated as time t 6 . In various circumstances, a bodily fluid can pass through the outer layer  21224   a  and the second layer  21224   b  to reach the third layer  21224   c  such that the outer layer  21224   a , the second layer  21224   b , and/or the third layer  21224   c  can begin to dissolve at the same, or at least substantially the same, time. In any event, the reader will note that the time t 3  in which the material comprising the second layer  21224   b  reaches its maximum efficacy or concentration can occur before time t 6 . At some later moment in time, the third layer  21224   c  can be completely, or at least substantially, dissolved by a moment in time indicated by time t 8 . As the reader will also note, the time t 8  can occur after time t 5 . 
     As the third layer  21224   c  is being dissolved, the bodily fluid can reach the fourth layer  21224   d  and begin to at least partially dissolve the fourth layer  21224   d  at a moment in time indicated by time t 4 . Similar to the above, the fourth layer  21224   b  can be completely dissolved over the course of minutes, hours, and/or days wherein the material comprising the fourth layer  21224   d  can reach a maximum efficacy or concentration at a moment in time indicated as time t 7 . In various circumstances, a bodily fluid can pass through the outer layer  21224   a , the second layer  21224   b , and the third layer  21224   c  to reach the fourth layer  21224   d  such that the outer layer  21224   a , the second layer  21224   b , the third layer  21224   c , and/or the fourth layer  21224   d  can begin to dissolve at the same, or at least substantially the same, time. In any event, the reader will note that the time t 6  in which the material comprising the third layer  21224   c  reaches its maximum efficacy or concentration can occur before time t 7 . At some later moment in time, the fourth layer  21224   d  can be completely, or at least substantially, dissolved by a moment in time indicated by time t 9 . As the reader will also note, the time t 9  can occur after time t 8 . In various embodiments, as a result of the above, a staged release of medicaments can occur. 
     In various embodiments, referring now to  FIGS. 81 and 83 , a staple cartridge  21300  can comprise a cartridge body  21310  including a plurality of staple cavities  21312  and a plurality of staples  21330  positioned therein. The staple cartridge  21300  can further comprise a tissue thickness compensator  21320  which can include a compensator body  21322  positionable against the cartridge body  21310  and, in addition, a plurality of discrete capsules  21324  positioned within the compensator body  21322 . In at least one embodiment, the capsules  21324  can be vertically oriented and, when the staples  21330  are in their unfired configuration, as illustrated in  FIG. 83 , each capsule  21324  can be positioned between the staple legs  21322  of a staple  21330 . In at least one such embodiment, the staple legs  21322  may at least partially extend into the tissue thickness compensator  21320  when the staples  21330  are in their unfired position without rupturing the capsules  21324 . When the staples  21330  are moved from their unfired position to their fired position, referring now to  FIG. 84 , the staples  21330  can rupture the capsules  21324  and thereby release the at least one medicament stored therein. More particularly, in at least one embodiment, the staples  21330  can be deformed by the forming pockets  21062  defined in the anvil  21060  when the staples  21330  are lifted upwardly such that the staple legs  21332  can be curled, or deformed, downwardly and inwardly toward the capsules  21324  positioned therebetween. In at least one embodiment, the staples  21330  can be lifted upwardly by a firing system comprising drivers  21340  and sled  21345  wherein the sled  21345  can be configured to longitudinally traverse the staple cartridge  21000  and sequentially lift and fire the staple drivers  21340  and the staples  21330  positioned thereon. In any event, the staple legs  21332  can pierce and/or crush the capsules  21324  such that the internal cavities  21326  defined in the capsules  21324  can be breached and the one or more medicaments contained in the internal cavities  21326  can escape therefrom. In various embodiments, the one or more medicaments can include one or more powders and/or fluids contained therein, for example. In various embodiments, the staple cartridge  21300  can further comprise a cutting member  21380  which can be advanced distally with the sled  21345  in order to transect the tissue T positioned between the staple cartridge  21300  and the anvil  21060 , for example. In at least one embodiment, the cutting member  21380  can be configured to pass through a knife slot  21314  defined in the cartridge body  21310  wherein, in at least one such embodiment, one or more capsules, such as capsules  21324 , for example, can be positioned within and/or above the knife slot  21314  such that the cutting member  21380  can transect such capsules  21324 . In any event, in various embodiments, the tissue thickness compensator  21320  can further comprise a layer  21321  positioned on the top, and/or bottom, of the cartridge body  21322  which, in at least one embodiment, can be comprised of hyaluronic acid, for example, and can stabilize the cartridge body  21322  and/or the staples  21330 . In at least one such embodiment, the cutting member  21380  can be configured to transect the layer  21321  when the cutting member  21380  is advanced through the staple cartridge  21300  as described above. 
     In various embodiments, referring now to  FIG. 85 , a tissue thickness compensator  21420  can comprise a compensator body  21422  and a plurality of capsules  21444  positioned therein. In at least one embodiment, similar to the above, each capsule  21444  can comprise a sealed cavity  21446  which can be configured to releasably store one or medicaments therein. In certain embodiments, each of the capsules  21444  can comprise a conical and/or tapered end  21447 , for example. In at least one such embodiment, the tapered ends  21447  can be utilized to hold the capsules  21444  in position while the cartridge body  21422  is being formed around it. In various embodiments, a mold can include a plurality of apertures and/or indentations which can be configured to receive and secure the tapered ends  21447  such that, when the compensator material is poured around the capsules  21444 , the mold can hold the capsules  21444  in position. In certain embodiments, further to the above, the capsules  21444  can be positioned and arranged such that they may not be ruptured or burst until staples are fired into and/or through the tissue thickness compensator  21420  during use, for example. 
     In certain other embodiments, referring now to  FIG. 86 , a tissue thickness compensator  21520  can comprise a plurality of capsules  21524  positioned within a compensator body  21522 . In at least one embodiment, the capsules  21524  can each comprise one or more apertures  21528  defined in the outer wall thereof wherein the apertures  21528  can be configured to permit one or medicaments  21525  to escape from the cavities  21526  defined in the capsules  21524 . In various embodiments, the apertures  21528  can be sized and configured to control the rate in which the medicaments  21525  escape from the cavities  21526 . For instance, larger apertures  21528  can permit a faster release of the medicaments  21525  while smaller apertures  21528  can permit a slower release of the medicaments  21525 , for example. In at least one embodiment, the outer wall of each capsule  21524  can be comprised of a tube having ends  21527  which are closed and/or sealed. In various embodiments, the outer walls of the capsules  21524  can be comprised of one or more bioabsorbable polymers, for example, and, in at least one embodiment, the ends  21527  can be closed and/or sealed utilizing a heat-staking process, a thermal-welding process, and/or a laser welding process, for example. In certain embodiments, the outer walls, or shells, of the capsules  21524  can be manufactured utilizing an injection molding process wherein, after the shells have been formed, one or medicaments can be positioned into the shells through one or more open ends thereof. Thereafter, in at least one embodiment, the open end, or ends, in the shell can be capped utilizing a polymer solution, for example. In embodiments in which the walls of the capsules  21524  are comprised of a bioabsorbable material, the apertures  21528  defined therein can grow over time. In at least one such embodiment, the rate in which the medicaments  21525  are released from the cavities  21526  can increase over time. 
     In various embodiments, the compensator body  21522  can be comprised of gelatin, for example, and can be manufactured into a foam material utilizing a lypholization process, for example. In at least one embodiment, the capsules  21524  can be inserted into the compensator body  21522  wherein, in at least one such embodiment, the compensator body  21522  can be formed with apertures configured to receive the capsules  21524 . In at least one such embodiment, a layer, or film, could then be placed over the compensator body  21522  to cap or enclose the capsules  21524  therein. In certain other embodiments, the capsules  21524  can be positioned within a mold and a compensator material can be formed at least partially around the capsules  21524  to form the compensator body  21522 . In any event, the compensator body  21552  can comprise one or more keying, or indexing, features which can be configured to align and orient the tissue thickness compensator  21520  with a cartridge body of staple cartridge such that the capsules  21524  are positioned in a desired position. 
     In various embodiments, referring now to  FIG. 87 , a surgical stapling system can include a staple cartridge  21600  and an anvil  21060 , wherein the staple cartridge  21600  and the anvil  21060  can be positioned on opposite sides of tissue T. Similar to other staple cartridges disclosed herein, the staple cartridge  21600  can comprise a cartridge body  21310  including a plurality of staple cavities  21312  and a plurality of staples  21330  positioned therein. In use, referring to  FIG. 91 , the staples  21330  can be lifted upwardly by drivers  21340  from an unfired position to a fired position such that they are deformed against the anvil  21060  or, more particularly, deformed within the forming pockets  21062 . As the staples  21330  are being fired, the staples  21330  can pierce the tissue T and a tissue thickness compensator  21620  attached to the anvil  21060  before the staples  21330  are deformed between their unfired configuration ( FIG. 88 ) and their fired configuration ( FIG. 89 ). In various embodiments, the staples  21330  can be comprised of any suitable material such as stainless steel and/or titanium, for example, and can be configured to apply a compression or clamping force against the tissue thickness compensator  21620  and the tissue T. In at least one embodiment, as illustrated in  FIG. 87 , the staples  21330  can be arranged in a plurality of rows wherein one staple  21330  can be positioned in each staple cavity  21312 . In various embodiments, the staple cartridge  21300  can further comprise piercing members  21635  ( FIG. 90 ) which can be configured to engage and pierce the tissue T, the tissue thickness compensator  21620 , and/or one or medicament capsules positioned within the tissue thickness compensator  21620 , for example. In at least one such embodiment, the piercing members  21635  can be positioned within the staple cavities  21312  wherein the piercing members  21635  can be fired, or ejected, from the staple cavities  21312  by the drivers  21340 . In certain embodiments, further to the above, some staple cavities  21312  of the staple cartridge  21600  can include staples  21330  positioned therein while other staple cavities  21312  can include piercing members  21635  positioned therein. In various embodiments, the staple cartridge  21600  can include some rows of staple cavities  21312  having only staples  21330  positioned therein, some rows having only piercing members  21635  positioned therein, and/or some rows having both staples  21330  and piercing members  21635  positioned therein. In at least the illustrated embodiment, referring to  FIG. 91 , the inner four rows of staple cavities  21312  may only comprise staples  21330  therein while the outer rows of staple cavities  21312  may comprise both staples  21330  and piercing members  21635  therein. In various embodiments, the staples  21330  and the piercing members  21635  within the outer rows of staple cavities  21312  may be arranged in an alternating arrangement, for example. Referring now to  FIG. 92 , in at least one embodiment, the staples  21330  and the piercing members  21635  may be arranged in a pattern which comprises two staples  21330 , followed by a piercing member  21635 , followed by two more staples  21330 , followed by a piercing member  21635 , and so forth, for example. 
     In various embodiments, referring primarily to  FIG. 90 , each piercing member  21635  can comprise a base  21638  and legs  21637  extending upwardly from opposite sides of the base  21638 . Referring now to  FIG. 91 , the drivers  21340  can each comprise a trough  21348  which can be configured to receive and support the base  21638  of a piercing member  21635 . When the drivers  21340  are pushed upwardly by the sled  21345 , referring now to  FIG. 92 , the sled  21345  can sequentially fire the staples  21330  and the piercing members  21635 . In various embodiments, referring now to  FIG. 91 , the staples  21330  may be deformed against the anvil  21060  while the piercing members  21635  may not touch the anvil  21060 . In at least one embodiment, referring primarily to  FIG. 90 , one or both of the legs  21636  of each piercing member  21635  can include a sharp tip  21639  which can be configured to pierce the tissue T and/or the tissue thickness compensator  21620  and at least one barb  21637  which can be configured to retain the legs  21636  in the tissue T and/or the tissue thickness compensator  21620 , for example. In some embodiments, a tissue thickness compensator may not be used at all. In certain embodiments, the legs  21636  of the piercing members  21635  may not be long enough to pass all the way through the tissue T, let alone touch the anvil  21060 . In certain other embodiments, the legs  21636  may be long enough such that they can contact the anvil  21060  and can be deformed into a different configuration. 
     In various embodiments, the piercing members  21635  can be comprised of a material that is different than the material comprising the staples  21330 . In at least one embodiment, the piercing members  21635  can be comprised of at least one bioabsorbable polymer, such as PGA, for example. In certain embodiments, the piercing members  21635  can each comprise at least one medicament, such as an anti-bacterial agent, an anti-inflammatory agent, pain medication, and/or a MMP inhibitor, for example. As the piercing members  21635  can be located within the staple lines, for example, the piercing members  21635  can supply one or more medicaments to the tissue T within and/or adjacent to the staple line as the piercing members  21635  are being dissolved and/or bioabsorbed. In various embodiments, the piercing members  21635  can be coated with one or more medicaments. In some embodiments, the piercing members  21635  can comprise one or more medicaments embedded within a structural substrate comprising the piercing members  21635 . In at least one embodiment, some piercing members  21635  can be comprised of a first structural substrate and/or a first medicament while other piercing members  21635  can be comprised of a second, or different, structural substrate and/or a second, or different, medicament, for example. In various embodiments, the piercing members  21635  can be manufactured utilizing an injection molding process, for example. 
     In various embodiments, referring now to  FIGS. 93 and 94 , a staple cartridge  21700  can include a cartridge body  21710  and a tissue thickness compensator  21720  positioned on or adjacent to a deck surface  21711  of the cartridge body  21710 . In at least one embodiment, similar to the above, the cartridge body  21710  can comprise a plurality of staples cavities  21312  and a plurality of staples positioned therein. The cartridge body  21710  can also include a slot  21714  which can be configured to receive a cutting member, such as cutting member  21380  ( FIG. 95 ), for example, therein. In use, as illustrated in  FIG. 95 , the cutting member  21380  can be configured to transect the tissue T positioned between the anvil  21060  and the staple cartridge  21700 . In various embodiments, referring again to  FIGS. 93 and 94 , the tissue thickness compensator  21720  can comprise a compensator body  21722  and a plurality of medicament packets, or capsules,  21724  positioned within the compensator body  21722 . In at least one embodiment, the capsules  21724  can be positioned and arranged in the compensator body  21722  such that the capsules  21724  overlie the slot  21714  defined in the cartridge body  21710 . In use, referring primarily to  FIG. 96 , the cutting member  21380  can be configured to incise the capsules  21724  as the cutting member  21380  is advanced through the staple cartridge  21700 . In at least one such embodiment, the capsules  21724  can be sealed prior to being incised by the cutting member  21380  and, after the capsules  21724  have been incised, the one or more medicaments contained therein can be released. Owing to the position of the capsules  21724  over the slot  21714 , in various embodiments, the one or more medicaments can be released onto the portion of the tissue T which has been transected by the cutting member  21380 . In at least one embodiment, the one or more medicaments contained within the capsules  21724  can comprise a biologic agent in the form of a powder, for example. In various embodiments, the one or more medicaments in the capsules  21724  can comprise oxidized regenerated cellulose, alginate, and/or calcium, for example. 
     In various embodiments, referring again to  FIGS. 93 and 94 , the capsules  21724  can comprise the same medicaments therein. In various other embodiments, one or more of the capsules  21724  can comprise one or more different medicaments therein. In at least one embodiment, a first plurality of capsules  21724  can comprise a first medicament therein and a second plurality of capsules  21724  can comprise a second medicament therein. In at least one such embodiment, the capsules  21724  can be arranged in an alternating arrangement along the longitudinal path of the cutting member  21380 , for example, such that a capsule  21724  including the first medicament can be followed by a capsule  21724  including the second medicament which can be followed by a capsule  21724  including the first medicament, and so forth, for example. In various embodiments, the cutting member  21380  can be configured to mix the first medicament and the second medicament together as the cutting member  21380  is advanced through the staple cartridge  21300 . In certain embodiments, referring again to  FIGS. 93 and 94 , the tissue thickness compensator  21720  can further comprise one or more channels  21726  extending outwardly from each capsule  21724 . In various embodiments, the channels  21726  can be configured to allow the medicaments within the capsules  21724  to migrate within the tissue thickness compensator  21720 , and the tissue T positioned thereagainst, after the capsules  21724  have been severed. In various embodiments, the capsules  21724  can be configured such that they do not burst when a compressive load is applied thereto by the anvil  21060 . In at least one embodiment, referring primarily to  FIGS. 93 and 96 , the cartridge body  21710  can comprise a plurality of recesses  21715  which can each be configured to receive at least a portion of a capsule  21724  therein. In at least one such embodiment, the recesses  21715  can be configured to permit the capsules  21724  to slide downwardly within the recesses  21715  when a compressive load is applied thereto such that the capsules  21724  may not burst. In various other embodiments, one or more of the capsules  21724  could be configured to burst only when a certain compressive force applied thereto is met or exceeded. In at least one such embodiment, the capsules  21724  can be configured to withstand the clamping pressure applied by the anvil  21060  but may burst when the compressive pressure applied thereto increases as a result of the cutting member  21380  being advanced through the staple cartridge  21700 , for example. In at least one embodiment, the capsules  21724  can include a lubricant therein which can facilitate the movement of the cutting member  21380  as it is advanced and/or retracted within the staple cartridge  21700 . 
     In various embodiments, referring now to  FIG. 97 , a tissue thickness compensator  21820  can comprise a compensator body  21822  and a longitudinal tube  21824  extending therethrough. In at least one embodiment, similar to the above, the tube  21824  can comprise a longitudinal cavity  21826  defined therein and one or more medicaments  21825  positioned within the cavity  21826 . In various embodiments, the longitudinal tube  21824  can further include one or more support legs  21827  extending outwardly therefrom which can be configured to support the tube  21824 . In at least one such embodiment, referring now to  FIG. 98 , the support legs  21827  can support the tube  21824  within a mold  21890  while the compensator body  21822  is formed around the tube  21824 . In various embodiments, referring now to  FIGS. 99 and 100 , the material comprising the compensator body  21822 , such as PGA and/or PCL, for example, can be poured around the tube  21824  and then lyophilized, foamed, and/or solidified, for example. In at least one embodiment, referring again to  FIG. 98 , the material comprising the compensator body  21822  can be poured into a cavity  21891  surrounding the tube  21824  wherein the cavity  21891  can then be closed by a cover  21892 . In various embodiments, referring to  FIG. 97 , the ends of the support legs  21827  may not be covered by the poured material and may be flush with the bottom surface  21821  of the compensator body  21822 . In at least one embodiment, the support legs  21827  and/or the tube  21824  can be comprised of a dissolvable and/or bioabsorbable material, such as gelatin, hyaluronic acid, PDS, and/or ORC, for example. In certain embodiments, the legs  21827  can be rapidly dissolved by bodily fluids and/or a saline solution, for example, wherein channels or passages can be left behind that extend between the outer perimeter and the interior of the tissue thickness compensator  21820 . In at least one embodiment, such passages can be created to permit the one or more medicaments  21825  positioned within the tube  21824  to be rapidly dissolved and/or absorbed. An alternative embodiment of a tissue thickness compensator, such as tissue thickness compensator  21920 , for example, can comprise a compensator body  21922  and a tube  21924  including a plurality of support legs  21927 , as illustrated in  FIG. 101 . In at least one embodiment, referring to  FIG. 102 , the support legs  21927  can be part of a larger support network or structural lattice  21928  that can extend through the compensator body  21922 . 
     In various embodiments, referring again to  FIG. 97 , the legs  21827  extending from the tube  21824  can also include one or more medicaments therein. When the legs  21827  are dissolved and/or absorbed, as described above, the one or more medicaments in the legs  21827  can provide a first medicated response to stapled and/or incised tissue while the one or more medicaments  21825  in the tube  21824  can provide a second, or subsequent, medicated response, in at least one embodiment. In certain embodiments, referring now to  FIGS. 103 and 105 , a tissue thickness compensator  22020  can comprise a compensator body  22022  and a longitudinal medicament tube  22024  extending through the compensator body  22022 . Similar to the above, the tube  22024  can define a longitudinal cavity  22026   a  including one or more medicaments  22025   a  positioned therein. Also similar to the above, the tube  22024  can include a plurality of longitudinal leg supports  22027  that can extend along the length of the tube  22024 . In various embodiments, each of the leg supports  22027  can define a longitudinal cavity, such as cavities  22026   b  and  22026   c , for example, therein which can each include one or more medicaments, such as medicaments  22025   b  and  22025   c , for example, therein. In various embodiments, the leg supports  22027  can be comprised of a material which can be quickly dissolved and/or absorbed such that the medicaments  22025   b  and  22025   c  can be quickly released. Thereafter, in at least one embodiment, the support legs  22027  and the tube  22024  can be further dissolved and/or absorbed such that the medicament  22025   a  can be subsequently released. In various embodiments, the medicaments  22025   a ,  22025   b , and/or  22025   c  can be comprised of the same material. In other embodiments, the medicaments  22025   a ,  22025   b , and/or  22025   c  can be comprised of different materials. In at least one embodiment, the medicaments  22025   b  and  22025   c  can be comprised of the same material, or materials, which can be different than the material, or materials, comprising medicament  22025   a.    
     In various embodiments, further to the above, the tube  22024 , the legs  22027 , and/or the cavities  22026   a - 22026   c  defined therein can be manufactured utilizing an injection molding process. In certain embodiments, the tube  22024 , the legs  22027 , and/or the cavities  22026   a - 22026   c  can be manufactured utilizing an extrusion process, for example, wherein, as a result, such features can comprise a continuous cross-section along the length thereof. As a result of such processes, in various embodiments, the tubes  22024  and the legs  22027  can be integrally formed. Thereafter, in at least one embodiment, the medicaments  22025   a - 22025   c  can be positioned within the cavities  22026   a - 22026   c , respectively. In various embodiments, the medicaments  22025   a - 22025   c  can each be comprised of one or more powders and/or one or more fluids, for example. In certain embodiments, referring now to  FIG. 106 , the ends  22029  of the cavities  22026   a - 22026   c  can be sealed in order to contain the medicaments  22025   a - 22025   c  therein. In any event, the tube  22024  can then be positioned within a mold, such as the mold  21890  described above, for example, wherein the material comprising the compensator body  22022  can be poured around the tube  22024 , as illustrated in  FIG. 104 , to form the tissue thickness compensator  22020 . Various alternative embodiments are illustrated in  FIGS. 107 and 108 . Referring to  FIG. 107 , a tissue thickness compensator  22120  can comprise a compensator body  22122  and a plurality of longitudinal tubes  22124  which are connected together. In at least one embodiment, each of the tubes  22124  can define a longitudinal cavity  22126  therein which can each include one or more medicaments  22125  therein. In various embodiments, the longitudinal cavities  22126  may not be in fluid communication with each other while, in some embodiments, one or more of the longitudinal cavities  22126  can be in fluid communication with each other. Similar to the above, the compensator  22120  can further comprise legs  22127  that extend downwardly from the tubes  22124  and can each include a longitudinal cavity  22126  and at least one medicament  22125  therein. In various embodiments, the tubes  22124  and/or the support legs  22127  can be comprised of materials which can be configured to dissolve and/or biabsorb at different rates. In at least one such embodiment, the support legs  22127  can be comprised of a material which can be dissolved and/or bioabsorbed at a faster rate than the material comprising the tubes  22124 , for example. Referring now to  FIG. 108 , a tissue thickness compensator  22220  can comprise a compensator body  22222  and a longitudinal tube  22224  wherein the tube  22224  can include a plurality of support legs  22227  extending therefrom. In at least one embodiment, a single longitudinal cavity  22226  can be defined within the tube  22224  and can extend into the support legs  22227 . Similar to the above, the cavity  22226  can include one or more medicaments  22225  positioned therein. 
     In various embodiments, referring again to  FIG. 97 , the support legs  21827  can be comprised of one or materials which can be configured to adsorb a fluid, such as blood and/or a saline solution, for example. In at least one embodiment, the support legs  21827  can be configured to wick the fluid toward the tube  21824  and the one or more medicaments  21825  contained therein. In certain embodiments, such wicking can allow the medicaments  21825  to dissolve and/or bioabsorb earlier in the healing process. In at least one embodiment, the ends of the support legs  21827  may not be covered by the compensator body  21822  and may be exposed to the fluid. In various embodiments, this wicking process can occur by capillary action and can occur regardless of the orientation of the tissue thickness compensator  21820 , for example. 
     In various embodiments, referring now to  FIG. 112 , a tissue thickness compensator  22320  can comprise a compensator body  22322  and a plurality of tubes  22324  positioned therein. In certain embodiments, the compensator body  23222  can be comprised of a regenerative tissue scaffold foam, such as an acellular omentum biomatrix, Omentum Scaffold Material, and/or ACell, for example. In at least one embodiment, the Omentum Scaffold Material can comprise a hydrophilic foam produced from skeletonized omentum and, in certain embodiments, can be compressible. When exposed to a fluid, the Omentum Scaffold Material can expand and apply pressure to the tissue positioned thereagainst. In at least one embodiment, ACell is a regenerative product that provides an extracellular matrix or scaffolding network to encourage cellular proliferation and migration. In at least one embodiment, the tissue scaffold comprising the compensator body  22322  can be loaded with stem cells, PRP, or growth factors, for example. In at least one embodiment, the tissue scaffold comprising the compensator body  22322  can be coated in a collagen matrix, for example. In various embodiments, the tissue scaffold matrix of the compensator body  22322  can be comprised of a fiber matrix and, in at least one embodiment, the fiber matrix can be comprised of randomly-oriented fibers. In some circumstances, a fiber matrix comprised of randomly-oriented fibers may not be able to provide a desired elasticity or resiliency within the compensator body  22322 . To account for this, in various embodiments, the randomly-oriented fibers can be comprised of a hydrophilic material and/or can be coated with a hydrophilic material which, after being exposed to a liquid, can be configured to expand and provide a desired resiliency to the fiber matrix and/or a desired compression force to the tissue. In various circumstances, the fiber matrix may not be exposed to a liquid until after it has been captured against tissue by a plurality of staples, as described above. In at least one such embodiment, the compensator body  22322  can comprise a liquid-impermeable wrap which can be broken, punctured, incised, and/or torn, for example, in use to allow the liquid to enter into the compensator body  22322  and access the hydrophilic fibers. In any event, when the liquid is absorbed by the scaffold matrix captured within the staples, the scaffold matrix can expand to apply a compressive pressure to the tissue also captured within the staples and, over time, accommodate tissue ingrowth into the scaffold matrix. 
     In various embodiments, further to the above, the tubes  22324  of the tissue thickness compensator  22320  can be comprised of a degradable material which can be configured to dissolve and/or bioabsorb. Similar to the above, each tube  22324  can include a sealed inner cavity having one or medicaments contained therein and, in addition, one or more support legs  22327  which can be configured to degrade and provide a channel or flow path for liquids to reach the medicament stored within the tube  22324 . Such degradation of the support legs  22327  may take time and, as a result, the medicament contained within the tubes  22324  may not be immediately released. In a sense, a period of time may be required for a fluid to degrade the legs  22327  wherein, as a result, the legs  22327  can serve as a fuse designed to delay the release of the medicament within the tubes  22324 . Thus, in various circumstances, legs  22327  having longer lengths and/or thicker cross-sections may provide a longer delay while legs  22327  having shorter lengths and/or thinner cross-sections may provide a shorter delay. In certain embodiments, the tubes  22324  can be comprised of a material which dissolves quickly and/or slowly; however, in either event, the degradation of the tubes  22324  can occur over a period of time which can delay the release of the one or more medicaments contained within the tubes  22324 . In various embodiments, a first tube  22324  can be comprised of a first material which degrades at a first rate and a second tube  22324  can be comprised of a second material which degrades at a second, or different, rate. In such embodiments, a first medicament contained within the first tube  22324  can be released before a second medicament contained within the second tube  22324 , for example. In certain embodiments, a first tube  22324  can have a thinner outer wall than a second tube  22324  which can allow the first tube  22324  to degrade faster than the second tube  22324  and allow a medicament contained within the first tube  22334  to be released before a medicament in the second tube  22324 , for example. As a result of the above, in various embodiments, a first tube  22324  can be configured to release a first medicament at a first point in time, a second tube  22324  can be configured to release a second medicament at a second, or later, point in time, and a third tube  22324  can be configured to release a third medicament at a third, or even later, point in time, for example. 
     In various embodiments, referring now to  FIGS. 113 and 114 , a tissue thickness compensator  22420  can comprise a compensator body  22422  and a sealed vessel  22424  positioned within the compensator body  22422 . In at least one embodiment, similar to the above, the vessel  22424  can define a longitudinal cavity  22426  and one or more medicaments  22425  positioned within the longitudinal cavity  22426 . In certain embodiments, the vessel  22424  can be resilient such that, when the tissue thickness compensator  22420  is compressed, or flattened, as illustrated in  FIG. 114 , the vessel  22424  can seek to spring back or retain its original, undeformed shape. In at least one such embodiment, the vessel  22424  can comprise an elastic spring member positioned within the compensator body  22422 . In at least one embodiment, the vessel  22424  can be configured to change shape without rupturing. In at least one such embodiment, the vessel  22424  can degrade when exposed to a liquid, for example, as described herein. 
     In various embodiments, referring now to  FIG. 115 , a tissue thickness compensator  22520  can comprise a compensator body  22522  and a plurality of sealed vessels  22524   a - 22524   c . In at least one embodiment, each of the vessels  22524   a - 22524   c  can define an outer perimeter which is configured to increase, maximize, and/or optimize the surface area of the vessel that comes into contact with a liquid, such as blood and/or a saline solution, for example. In various circumstances, vessels having a larger surface area may be exposed to a larger quantity of liquid and, as a result, can be dissolved and/or bioabsorbed at a faster rate. Correspondingly, vessels having a smaller surface area may be exposed to a smaller quantity of liquid and, as a result, can be dissolved and/or bioabsorbed at a slower rate. In various embodiments, the vessels  22524   a - 22524   c  can be comprised of gelatin, hyaluronic acid, PDS, and/or ORC, for example. Similar to the above, in certain embodiments, the vessels  22524   a - 22524   c  can be resilient and can provide a spring-back or elastic biasing force. In various embodiments, referring now to  FIG. 116 , a tissue thickness compensator  22620  can comprise a compensator body  22622  and a plurality of resilient laminate members  22624  positioned within the compensator body  22622 . In at least one embodiment, each of the laminate members  22624  can comprise a sealed inner channel including one or more medicaments positioned therein. 
     In various embodiments, referring now to  FIG. 117 , an end effector of a surgical stapling instrument can comprise an anvil  21060  and a staple cartridge  22700 . In at least one embodiment, the anvil  21060  can comprise a tissue thickness compensator  22770  attached thereto and the staple cartridge  22700  can comprise a cartridge body  22710  and a tissue thickness compensator  22720 . In certain embodiments, referring now to  FIG. 118 , the tissue thickness compensator  22770  can comprise a plurality of layers wherein, in at least one embodiment, the tissue thickness compensator  22720  can comprise a first layer  22771  and a second layer  22772 , although other embodiments are envisioned in which a tissue thickness compensator can comprise more than two layers. In various embodiments, one or more of the layers of the tissue thickness compensator can comprise a woven material. In at least one embodiment, the first layer  22771  can be comprised of a plurality of first threads  22773  comprised of a first material and a plurality of second threads  22774  comprised of a second, or different, material. Similarly, the second layer  22772  can be comprised of a plurality of first threads  22773  and a plurality of second threads  22774 . In certain embodiments, the concentrations of the first threads  22773  and the second threads  22774  in the first layer  22771  can be the same as the concentrations of the first threads  22773  and the second threads  22774  in the second layer  22772 . In certain other embodiments, the concentrations of the first threads  22773  and the second threads  22774  in the first layer  22771  can be different than the concentrations of the first threads  22773  and the second threads  22774  in the second layer  22772 , as discussed in greater detail below. 
     In various embodiments, further to the above, the first threads  22773  can be comprised of bioabsorbable polymer, such as PGA, PDS, PCL, and/or PLA, for example, and the second threads  22774  can be comprised of oxidized regenerated cellulose (ORC), for example. In certain embodiments, the first layer  22771  can comprise an outer layer of the tissue thickness compensator  22770  and can include a tissue contacting surface. In at least one embodiment, the first layer  22771  can comprise more first threads  22773  than second threads  22774 . In at least one such embodiment, the first layer  22771  can comprise a ratio of approximately 80% first threads  22773  to approximately 20% second threads  22774 , for example. In various embodiments, the first layer  22771  can comprise a ratio of approximately 60% first threads  22773  to approximately 40% second threads  22774 , a ratio of approximately 67% first threads  22773  to approximately 33% second threads  22774 , a ratio of approximately 70% first threads  22773  to approximately 30% second threads  22774 , a ratio of approximately 75% first threads  22773  to approximately 25% second threads  22774 , and/or a ratio of approximately 90% first threads  22773  to approximately 10% second threads  22774 , for example. 
     In various embodiments, further to the above, the first threads  22773  can be comprised of a material which dissolves, bioabsorbs, and/or changes state at a slower rate than the material comprising the second threads  22774 . In at least one such embodiment, the second threads  22774  can be comprised of ORC threads which can change from a solid to a gel when they are exposed to a liquid, for example, and, in at least one embodiment, the ORC threads can react and change from a solid to a gel when they are exposed to platelets, for example. In such embodiments, however, the first layer  22773  can be mostly comprised of bioabsorbable polymer threads which can react to liquids much slower than the ORC threads and, thus, in at least one embodiment, the first layer  22773  can come into contact with tissue or bodily fluids on multiple occasions without losing its overall shape and structure. That said, the ORC fibers in the first layer  22773  can react when they first come into contact with a liquid and/or tissue; however, the ORC gel can be at least partially or mostly retained within the first layer  22773 . 
     In various embodiments, the second layer  22772  can comprise an inner layer of the tissue thickness compensator  22770  and may not include a direct tissue contacting surface. In at least one embodiment, the second layer  22772  can comprise less first threads  22773  than second threads  22774 . In at least one such embodiment, the second layer  22772  can comprise a ratio of approximately 20% first threads  22773  to approximately 80% second threads  22774 , for example. In various embodiments, the second layer  22772  can comprise a ratio of approximately 40% first threads  22773  to approximately 60% second threads  22774 , a ratio of approximately 33% first threads  22773  to approximately 67% second threads  22774 , a ratio of approximately 30% first threads  22773  to approximately 70% second threads  22774 , a ratio of approximately 25% first threads  22773  to approximately 75% second threads  22774 , and/or a ratio of approximately 10% first threads  22773  to approximately 90% second threads  22774 , for example. 
     In various embodiments, further to the above, the second layer  22772  can comprise more ORC threads than bioabsorbable polymer threads, for example. In certain embodiments, the second layer  22772  can comprise more ORC threads than the first layer  22771 . As the second layer  22772  is not an outer layer, in various embodiments, liquids may not immediately contact the second layer  22772  as they would have to first pass through the first layer  22771  before contacting the second layer  22772 . In such embodiments, the second layer  22772  can comprise a higher density of ORC threads as the ORC threads in the second, protected, layer  22772  would not immediately turn into a gel. Even if the ORC threads in the second layer  22772  were to come into contact with a liquid and turn into a gel, the ORC gel could be contained in the tissue thickness compensator  22770  by the first layer  22771  which, as described above, can maintain its general shape, at least initially, and provide a support mesh to the second layer  22772 . While ORC fibers and bioabsorbale fibers can be utilized in various embodiments, other suitable materials could be utilized. 
     Further to the above, referring now to  FIGS. 121-123 , the tissue thickness compensator  22770  can be positioned intermediate an anvil  21060  and tissue T, wherein the tissue thickness compensator  22770  can be compressed against the tissue T before staples  21330  are fired from the staple cartridge  22700 . After the staples  21330  have been fired to capture the tissue T and the tissue thickness compensators  22720  and  22770  therein, the anvil  21060  and the cartridge body  22710  of the staple cartridge  22700  can be moved away from the compensators  22720 ,  22770  and the tissue T and removed from the surgical site. In various embodiments, referring now to  FIG. 119 , a layer  22871  of a tissue thickness compensator can comprise woven threads  22873  which can include an elongate, or flattened, cross-section, for example. In certain embodiments, referring now to  FIG. 120 , a layer  22971  of a tissue thickness compensator can comprise woven threads  22973  which can include a round cross-section, for example. 
     Various alternative embodiments are illustrated in  FIGS. 124-127 . Referring now to  FIG. 125 , an end effector of a surgical stapling instrument can include an anvil  21060  and a tissue thickness compensator  22770 ′ positioned thereon. In various embodiments, referring to  FIG. 124 , the tissue thickness compensator  22270 ′ can comprise a layer  22771 ′ which can include a plurality of first fibers  22773 ′ woven with a plurality of second fibers  22774 ′. In at least one such embodiment, the first fibers  22773 ′ can be configured to dissolve and/or bioabsorb at a faster rate than the second fibers  22774 ′. In certain embodiments, gaps, openings, and/or pockets can be defined between the first fibers  22773 ′ and the second fibers  22773 ″ which can permit liquids to flow through the layer  22771 ′. Referring now to  FIG. 127 , an end effector of a surgical stapling instrument can include a tissue thickness compensator  22770 ″ attached to an anvil  21060 . In various embodiments, referring to  FIG. 126 , the tissue thickness compensator  22770 ″ can comprise a woven layer of threads  22771 ″ which can be embedded and/or encased within a substrate  22772 ″. In at least one embodiment, the threads  22771 ″ can be exposed while, in other embodiments, at least a portion of the substrate  22772 ″ may have to be dissolved and/or bioabsorbed before the threads  22771 ″ are exposed. In at least one such embodiment, the material comprising the substrate  22772 ″ may fill within any gaps, openings, or pockets defined between the threads  22771 ″. 
     In various embodiments, referring now to  FIG. 132 , a staple cartridge  23000  can include a tissue thickness compensator  23020 . As discussed herein, a tissue thickness compensator can be manufactured utilizing a lypholization process, for example. In at least one embodiment, a solution comprising PGA and/or PCL, for example, can be poured into a mold wherein the solution can be permitted to grow into an open cell foam in the presence of a vacuum atmosphere and/or reduced temperature, for example. In at least one such embodiment, the PGA material can be present in the solution according to an approximately 64/36 ratio by weight with respect to the PLA material, for example. In various embodiments, referring to  FIG. 128 , fibers and/or filaments  23021 , for example, can be mixed into the solution. In at least one embodiment, PGA fibers, for example, can be dispersed within the solution before it is poured into the mold such that the PGA fibers can be evenly, or at least substantially evenly, distributed throughout the tissue thickness compensator  23020 , for example. In other circumstances, the PGA fibers can be placed in the solution, and/or directly into the mold, for example, such that the PGA fibers can precipitate or settle toward the bottom of the mold, for example. In other circumstances, the PGA fibers could be configured to float to the top of the solution. In any event, in certain embodiments, a solvent, such as dioxane solvent, for example, can be present in the solution which can assist in the lypholization process. In various embodiments, the dioxane solvent may not react, or at least substantially react, with the PGA fibers within the solution. 
     In various embodiments, further to the above, the fibers  23021  can be coated with one or more medicaments before they are mixed into and/or with the solution. In certain embodiments, referring to  FIG. 130 , each fiber  23021  can comprise a substrate  23022  which can be at least partially coated with a coating  23023  utilizing any suitable manufacturing process. Referring to  FIG. 129  the fibers  23021  can be manufactured utilizing an extruding process in which at least one drug coating is placed on a PGA substrate, for example. Such embodiments may be particularly useful for drugs that can withstand the elevated temperature of an extruding process. Referring to  FIG. 131 , the fibers  23021  can be coated and/or impregnated with a drug utilizing a carrier fluid, such as supercritical carbon dioxide, for example. In any event, in various embodiments, the drug-coated fibers  23021  can be mixed with the solution such that the fibers  23021  become embedded within the tissue thickness compensator  23020 . In various circumstances, as a result, the coatings of the fibers  23021  may begin to dissolve and elude the one or more medicaments contained therein. In certain embodiments, the fibers  23021  positioned closer to the perimeter of the tissue thickness compensator  23020  may begin to dissolve before the fibers  23021  positioned closer to the interior of the tissue thickness compensator  23020 . In such embodiments, the dissolved fibers  23021  may leave behind a plurality, or network, of cavities within the tissue thickness compensator  23020  wherein, in at least one embodiment, such cavities can permit cellular or tissue ingrowth within the tissue thickness compensator  23020 . In certain embodiments, a tissue thickness compensator can comprise a plurality of first fibers which can dissolve at a faster than a plurality of second fibers. In at least one such embodiment, the first fibers can comprise PGA fibers, for example, which have been gamma irradiated. In various embodiments, gamma irradiated PGA fibers can dissolve faster than non-gamma irradiated PGA fibers, for example. 
     In various embodiments, one or more colorants can be added to the solution described above such that the tissue thickness compensator produced from the solution can have a suitable color. In at least one embodiment, it may be desirable for the tissue thickness compensator to have a color which contrasts with its surrounding environment. In at least one such embodiment, the tissue thickness compensator can be green and/or blue, for example. 
     In various embodiments, referring now to  FIGS. 133 and 135 , a tissue thickness compensator  23120  can comprise a compensator body  23122  and a plurality of medicament particles  23121  distributed throughout the compensator body  23122 . In at least one embodiment, the compensator body  23122  can be comprised of a hydrophobic material. In at least one such embodiment, the compensator body  23122  can be comprised of a material including PCL/PGA, for example, wherein the PCL and PGA can be present in the material according to a 65/35 ratio by weight. In certain embodiments, referring now to  FIG. 134 , the medicament particles  23121  can comprise one or more drugs  23123 , such as doxycycline, percarbonate, and/or ascorbic acid phosphate, for example, which can be encapsulated by and/or incorporated within a casing or shell  23124  comprised of a hydrophilic material, for example. In at least one embodiment, the shell  23124  can be comprised of low molecular weight gelatin, hyaluronic acid, and/or CMC, for example. In various embodiments, the medicament  23121  can be manufactured as microparticles which can be distributed within a solution and poured into a mold where the solution can be subsequently lyophilized, for example, as described above. Once the tissue thickness compensator  23120  has been exposed to a liquid, in use, a fluid  23129  ( FIG. 136 ) can enter into the compensator body  23122  and dissolve and/or absorb the hydrophilic shell  23124  of the medicament particles  23121 , for example. In various embodiments, referring now to  FIG. 139 , a tissue thickness compensator  23220  can comprise a first layer  23222  and a second, or outer, layer  23224  which, in at least one embodiment, can comprise a plurality of coated drug particles  23221  dispersed therein. Similar to the above, the particles  23221  can be dissolved and/or absorbed from the second layer  23224  and can leave behind openings or capillary paths  23225 , for example, within the second layer  23224 , for example. In certain embodiments, referring now to  FIG. 140 , a tissue thickness compensator  23320  can comprise a compensator body  23322  comprising a plurality of medicament particles  23121  and a plurality of fibers  23021  distributed therein, for example. 
     In various embodiments, referring now to  FIGS. 141 and 142 , a staple cartridge  23400  can include a cartridge body  23410  and a tissue thickness compensator  23420  positioned thereon, for example. In at least one embodiment, the tissue thickness compensator  23420  can comprise a plurality of capsules  23421  positioned within the compensator body  23422 . In certain embodiments, the capsules  23421  can be manufactured utilizing an emoulism, or spin disk, process, for example, and, in at least one embodiment, the capsules  23421  can comprise microspheres of solid and/or liquid biometrics, for example. In various embodiments, the capsules  23421  can include one or more adhesives which, when released from the capsules  23421 , can help secure tissue sealing. Certain embodiments are envisioned in which the capsules  23421  can include haemostatic agents, for example. In any event, in various embodiments, the capsules  23421  can be distributed within the compensator body  23422  in any suitable manner. In at least one embodiment, referring now to  FIG. 143 , the capsules  23421  can be placed in a mold cavity  21891  defined in a mold  21890 , for example, wherein the capsules  23421  can settle to the bottom  21893  of the mold  21890 . In certain embodiments, referring to  FIG. 144 , the mold  21890  can be vibrated such that the capsules  23421  can form an even, or an at least substantially even, layer on the bottom  21893 . In various embodiments, referring now to  FIG. 145 , the material comprising the compensator body  23422  can be poured into the mold cavity  21891  with the capsules  23421 . In certain embodiments, the capsules  23421  can be denser than the compensator body material and, as a result, the capsules  23421  may remain at the bottom  21893  of the mold  21890  as illustrated in  FIG. 146 . In at least one such embodiment, referring to  FIG. 148 , the bottom  21893  of the mold  21890  can include a plurality of recesses, depressions, and/or dimples  21899  which can be configured to receive the capsules  23421 . In certain other embodiments, referring to  FIG. 147 , the capsules  23421  can be less dense than the compensator body material and may float to the top of the mold  21890 . In various embodiments, as described in greater detail further below, the density of the capsules  23421  can be selected such that the capsules  23421  can float throughout the compensator body material. 
     After the mixture comprising the capsules  23421  and the compensator body material has been suitably poured into the mold  21890 , the mixture can undergo a lypholization process, for example, to form the tissue thickness compensator  23420 . In at least one such embodiment, the capsules  23421  can be secured or freeze-dried into position within the compensator body  23422 . Thereafter, referring again to  FIG. 141 , the tissue thickness compensator  23420  can be removed from the mold  21890  and then assembled to the cartridge body  23410  of the staple cartridge  23400 . As illustrated in  FIG. 141 , the tissue thickness compensator  23420  can be positioned and arranged such that capsules  23421  can define, or are positioned adjacent to, a tissue-contacting surface, or skin,  23425  of the tissue thickness compensator  23420 . In certain embodiments, the capsules  23421  can be at least partially comprised of a hydrophilic material, for example, which can be quickly dissolved and/or bioabsorbed after the tissue thickness compensator  23420  has been positioned against tissue, for example. In at least one embodiment, each of the capsules  23421  can be comprised of multiple layers of materials which can be dissolved and/or bioabsorbed over time. In at least one such embodiment, an outer layer of a capsule  23421  can comprise a first medicament which can be dissolved and/or bioabsorbed to expose a second, or inner, layer comprising a second medicament which can then be dissolved and/or bioabsorbed, for example. In at least one embodiment, some of the capsules  23421  can be positioned such that they are incised by a cutting member, described elsewhere herein, as the cutting member is progressed distally to incise the tissue and/or the tissue thickness compensator  23420 . In at least one embodiment, the capsules  23421  can decrease the density of the tissue thickness compensator  23420  which can reduce the force or energy needed to advance the cutting member through the tissue thickness compensator  23420 , for example. 
     As discussed above, various embodiments of a tissue thickness compensator  23420  can comprise capsules  23421  positioned on one or more sides, or skins, on the compensator body  23422 . As also discussed above, certain embodiments of a tissue thickness compensator  23420  can comprise capsules  23421  dispersed throughout the compensator body  23422 . In at least one such embodiment, the capsules  23421  can have the same density of the compensator body material such that the capsules  23421  can float within the compensator body material. In certain embodiments, the capsules  23421  can be dispersed, or homogenized, throughout the compensator body material wherein the mixture can then be cooled before the capsules  23421  settle, or at least substantially settle, to the bottom of the mold. 
     In various embodiments, referring now to  FIG. 149 , a tissue thickness compensator  23520  can comprise a shell  23522  and a plurality of movable elements  23524  positioned within the shell  23522 . In at least one embodiment, the shell  23322  can define an enclosed and/or sealed space, such as cavity  23523 , for example, within which the movable elements  23524  can move. In certain embodiments, the movable elements  23254  can be spherical in shape, for example, and can be configured to slide and/or roll, for example, relative to each other. In various embodiments, the tissue thickness compensator  23520  can be positioned over a cartridge body  21310  of a staple cartridge wherein staples  21330  can be fired from the staple cartridge and through the tissue thickness compensator  23520 , as illustrated in  FIG. 150 . In various circumstances, the movable elements  23524  can be configured to move to the sides of the staples  21330  being fired through the tissue thickness compensator  23520  such that the elements  23524  may not be ruptured during the firing process. In at least one such embodiment, the shell  23522  can be comprised of a resilient material which can be configured to flex and/or shift in order to accommodate the movement of the movable elements  23524  and dynamically redistribute the forces generated within. In certain embodiments, the shell  23522  can enclose a medium. In at least one such embodiment, the medium can comprise one or more powders, liquids, gasses, fluids, and/or gels, for example, within which the movable elements  23524  can move. In various embodiments, the movable elements  23524  can be comprised of a dissolvable and/or bioabsorbable material, for example, and one or more medicaments contained therein. In at least one such embodiment, such an arrangement can be configured to provide a delayed and/or sustained release of the one or more medicaments. In certain alternative embodiments, although not illustrated, the tissue thickness compensator  23520  can be positioned between the tissue T and an anvil  21060 , for example. In any event, in various embodiments, the tissue thickness compensator  23520  can comprise an enclosed “bean bag” arrangement. In certain embodiments, the shell  23522  can be configured such that it does not rupture, or at least substantially rupture, until a cutting member, such as cutting member  21380 , for example, is passed therethrough. At such point, in various embodiments, one or more of the movable elements  23524  could escape from the shell  23522 . 
     In various embodiments, referring now to  FIG. 153 , a tissue thickness compensator  23620  can comprise a compensator body  23622  and a plurality of capsules  23624  at least partially contained therein. In certain embodiments, referring now to  FIG. 151 , a mold  23690  can be utilized to manufacture the tissue thickness compensator  23620 . In at least one such embodiment, a plurality of spherical capsules  23624  can be positioned within a cavity  23691  defined in the mold  23690  wherein the lateral movement of the capsules  23624  within the mold  23690  can be arrested or stopped by lateral sidewalls  23694  of the mold  23690  and lateral stops  23693  extending between the lateral sidewalls  23694 , for example. In various embodiments, the lateral sidewalls  23694  and the lateral stops  23693  can define a plurality of pockets within which the capsules  23624  can be positioned and contained. In certain embodiments, the capsules  23624  can be configured to rest on the bottom surface  23699  of the mold  23690 . In other embodiments, referring to  FIGS. 151 and 152 , the mold  23690  can further comprise one or more longitudinal supports  23692  which can be configured to suspend the capsules  23624  such that they are not in contact with the bottom surface  23699  of the mold  23690 . In at least one such embodiment, the longitudinal supports  23692  can be positioned on the bottom surface  23699  while, in other embodiments, referring to  FIG. 152 , the longitudinal supports  23692  can be positioned on the lateral supports  23693 . 
     In various embodiments, referring again to  FIGS. 151 and 152 , a material comprising the compensator body  23622  can be poured into the cavity  23691  of the mold  23690  such that the capsules  23624  are at least substantially surrounded by the material. In at least one embodiment, referring primarily to  FIG. 153 , portions of the capsules  23624  can protrude from the compensator body  23622  of a tissue thickness compensator  23620 . In certain embodiments, the lateral supports  23693  and/or the longitudinal supports  23692  can be withdrawn from the mold  23691  during and/or after the compensator body  23622  has undergone a lypholization process, for example. At such point, the capsules  23624  can be suspended within the compensator body  23622  without structural supports. In various other embodiments, the lateral supports  23693  and/or the longitudinal supports  23692  can remain in the compensator body  23622 . In at least one such embodiment, the lateral supports  23693  and/or the longitudinal supports  23692  can be comprised of a bioabsorbable material, for example. In certain embodiments, the supports  23692  and/or the supports  23693  can comprise elastic members positioned within the compensator body  23622  which can increase the resiliency of the compensator body  23622 , for example. 
     In various embodiments, referring now to  FIG. 157 , a tissue thickness compensator  23720  can comprise a compensator body having first and second portions,  23722   a  and  23722   b , and at least one capsule  23724  positioned therebetween. In at least one embodiment, the tissue thickness compensator  23720  can be manufactured utilizing mold  21890 , for example. Referring now to  FIG. 154 , a first material can be poured into the mold  21890  to form the first portion  23722   a  of the compensator body. Thereafter, referring to  FIG. 155 , the capsule  23724  can be positioned on the first portion  23722   a . In some embodiments, the capsule  23724  can be positioned on the first portion  23722   a  after a period of time and/or after the first material has undergone a lypholization process, for example. Referring now to  FIG. 156 , a second material can be poured into the mold  21890  to form the second portion  23722   b  of the compensator body. After a period of time and/or after the second material has undergone a lypholization process, for example, the tissue thickness compensator  23720  can be removed from the mold  21890  and used in connection with a staple cartridge  23700  as illustrated in  FIG. 158 , for example. In certain embodiments, the second material can be different than the first material while, in other embodiments, the second material can be the same as the first material. In either event, in various embodiments, the first material and/or the second material can be comprised of a bioabsorbable material and the capsule  23724  can be comprised of at least one medicament, for example. 
     In various embodiments, referring now to  FIG. 162 , a staple cartridge  23800  can comprise a tissue thickness compensator  23820  which can include a compensator body  23822  and a longitudinal capsule  23824  positioned therein. In at least one embodiment, referring now to  FIGS. 159 and 160 , a longitudinal aperture  23821  can be formed in the compensator body  23822  by any suitable process such as by a mechanical drilling process and/or a laser drilling process, for example. Once the longitudinal aperture  23821  has been formed, a longitudinal capsule  23824  can be positioned within the longitudinal aperture  23821 , as illustrated in  FIG. 161 . In various embodiments, referring now to  FIG. 166 , a staple cartridge  23900  can comprise a tissue thickness compensator  23920  which can include a compensator body  23922  and a plurality of transverse capsules  23924  positioned therein. In at least one embodiment, referring now to  FIGS. 163 and 164 , transverse apertures  23921  can be formed in the compensator body  23922  by any suitable process such as by a mechanical drilling process and/or a laser drilling process, for example. Once the transverse apertures  23921  have been formed, a plurality of transverse capsules  239824  can be positioned within the transverse apertures  23921 , as illustrated in  FIG. 165 . 
       FIGS. 167-171  illustrate an alternative method for manufacturing the tissue thickness compensator  23820  utilizing a vertical mold  24090 . Referring primarily to  FIG. 167 , the mold  24090  can include a cavity  24091  defined by sidewalls  24092  and a bottom end wall  24093 . In at least one embodiment, referring to  FIG. 168 , the end wall  24093  can comprise an aperture  24094  which can be configured to receive an end of the longitudinal capsule  23824  and hold the capsule  23824  in an upright position, as illustrated in  FIG. 169 . Thereafter, referring now to  FIG. 170 , the open side of the cavity  24091  can be closed and/or sealed by a cover  24095  such that the material comprising the compensator body  23822  can be poured into the cavity  24091  through an open end of the mold  24090 . After the material comprising the compensator body has solidified, cured, and/or lyophilized, for example, the tissue thickness compensator  23820  can be removed from the mold  24090 . 
     In various embodiments, referring now to  FIG. 172 , a staple cartridge  24100  can comprise a cartridge body  24110 , a tissue thickness compensator mat  24170  positioned against a deck surface  24111  of the cartridge body  24110 , and a tissue thickness compensator  24120  positioned on top of the tissue thickness compensator mat  24170 . In at least one embodiment, the tissue thickness compensator  24120  and the tissue thickness compensator mat  24170 , together or independently, can compensate for variations in the thickness of the tissue captured within staples, such as staples  21330  ( FIG. 175 ), for example, fired from the staple cartridge  24100 . In various embodiments, referring primarily to  FIGS. 172 and 173 , the compensator mat  24170  can comprise a bottom surface  24171  configured to abut the deck surface  24111  and, in addition, an attachment flange or rail  24174  extending from the bottom surface  24171  which can be configured to be securely received within a knife slot  24114  defined in the cartridge body  24110 . The compensator mat  24170  can further comprise a plurality of packets  24172  which can extend transversely across the compensator mat  24170 . In at least one such embodiment, each of the packets  24172  can be defined along a transverse axis which is transverse to and/or perpendicular to a longitudinal axis defined by the knife slot  24114 , as illustrated in  FIG. 176 . In various embodiments, the compensator mat  24170  can comprise a plurality of layers between which the packets  24172  can be defined. In at least one such embodiment, the layers can be comprised of PDS and/or collagen, for example. In at least one embodiment, each packet  24172  can be configured to store one or more medicaments therein such as doxycycline, a coagulant, and/or an anti-microbial material, for example. 
     Referring again to  FIG. 175 , the tissue thickness compensator mat  24170  can be positioned relative to the cartridge body  24110  such that the packets  24172  overlie the staple cavities  21312  defined in the cartridge body  24110 . More particularly, in at least one embodiment, each packet  24172  can be positioned and arranged such that it extends between the staples legs  21332  of a staple  21330 . In various embodiments, the compensator mat  24170  can comprise a plurality of apertures and/or throughholes which can be configured to receive the ends of the staples  21330 , for example. These throughholes can be positioned adjacent to the packets  24172 , for example. As the staples  21330  are moved from an unfired position to a fired position, as illustrated in  FIG. 175 , the staples  21330  can be configured to capture the packets  24172  therein. In at least one such embodiment, the staples  21330  and the packets  24172  can be configured and arranged such that the packets  24172  are not punctured or ruptured while the staples  21330  are being fired. In such embodiments, the packets  24172  can provide a resilient or compressive pressure to the tissue T captured within the staples  21330  and can consume gaps between the tissue T and the staples  21330 , for example. In various embodiments, referring again to  FIG. 176 , the packets  24172  can be incised by the cutting member  21380  as the cutting member  21380  is advanced through the knife slot  24114  defined in the cartridge body  24110 , the tissue T, and/or the compensator mat  24170 . The reader will note that the tissue thickness compensator  24120  is not depicted in  FIGS. 175 and 176 . Various embodiments are envisioned in which the staple cartridge  24100  includes the tissue thickness compensator mat  24170  and not the tissue thickness compensator  24120  while, in other embodiments, referring now to  FIG. 177 , the staple cartridge  24100  can include both the tissue thickness compensator mat  24170  and the tissue thickness compensator  24120 , for example. 
     An alternative embodiment of a staple cartridge is illustrated in  FIG. 178 . In various embodiments, a circular staple cartridge  24200  can comprise a circular cartridge body  24210  including a plurality of staple cavities  21312  arranged in concentric circles, for example. In at least one such embodiment, the staple cartridge  24200  can further comprise a circular tissue thickness compensator mat  24270  positioned on the cartridge body  24210  wherein the compensator mat  24270  can comprise packets  24272  which extend radially outwardly, for example. In certain embodiments, similar to the above, the packets  24272  can extend in directions which overlie the staple cavities  21312  such that the packets  24272  can extend between the legs of staples  21330  positioned within the staple cavities  21312 . Also similar to the above, the staples  21330  can be configured to capture the packets  24272  therein when the staples  21330  are fired from the staple cartridge  24200 . 
     In various embodiments, referring now to  FIG. 189 , a staple cartridge  24300  can include a cartridge body  24310  and a tissue thickness compensator  24320  including a compensator body  24322  and a plurality of tubular members  24324  positioned within the compensator body  24322 . In at least one such embodiment, the staple cartridge  24300  can further comprise a tissue thickness compensator layer, or sheet,  24370 , for example, positioned intermediate the tissue thickness compensator  24320  and the cartridge body  24310 . In certain embodiments, referring now to  FIG. 179 , a plurality of staple cartridges  24300  can be manufactured simultaneously utilizing a mold  24390 . The mold  24390  can include a plurality of cavities  24391  which can each be configured to receive a cartridge body  24310  therein, as illustrated in  FIG. 180 . Thereafter, one or more large sheets of material comprising the tissue thickness compensator layer  24370  can be placed over the cartridge bodies  24310 . In at least one embodiment, the mold  24390  can include a plurality of upwardly-extending support pins or posts  24392  wherein the sheets  24370  can be positioned against the posts  24392  and then pushed downwardly such that the posts  24392  can puncture the sheets  24370  as illustrated in  FIGS. 181 and 183 . In various embodiments, referring now to  FIGS. 182 and 184 , an elongate tube, or tubes,  24324  can be wound around and between the posts  24392  such that the tube  24324  passes over each cartridge body  24310  at least once. In at least one embodiment, the tube  24324  can be wound around and between the posts  24392  such that the tube  24324  passes over each cartridge body  24310  six times, for example. In certain embodiments, the tube  24324  can be permitted to rest on the sheets  24370  while, in certain other embodiments, the tube  24324  can be wound tightly around and between the posts  24392  such that the tube  24324  is taut and can be suspended above the sheets  24370 . Once the tube  24324  has been suitably positioned, referring primarily to  FIG. 185 , a material comprising the compensator body  24322  can be poured into the mold  24390  on top of the sheets  24370 . In at least one embodiment, the sheets  24370  can be configured to protect, or mask, the cartridge bodies  24310  and can prevent the compensator body material  24322  from entering into the staple cavities  21312  defined in the cartridge bodies  24310 , for example. In various embodiments, a sufficient amount of compensator body material  24322  can be poured into the mold such that the compensator body material  24322  covers the elongate tube  24322 . 
     In various embodiments, further to the above, the compensator body material  24322  can then be cured, solidified, and/or lyophilized, for example, to form the tissue thickness compensators  24320  on top of the cartridge bodies  24310 . Thereafter, in at least one embodiment, referring now to  FIG. 186 , a cutting die  24395  can be utilized to cut the compensator body material  24322 , the tissue thickness compensator sheets  24370 , and the elongate tube  24322 . In various embodiments, referring now to  FIG. 187 , the cutting die  24395  can comprise a plurality of cutting blades  24396  which can be configured to singulate and detach the tissue thickness compensators  24320  and the tissue thickness compensator sheets  24370  from one another. In certain embodiments, the cutting die  24395  can include a plurality of wells  24397  which can be configured to remove any excess material between the singulated tissue thickness compensators  24320  and the tissue thickness compensator sheets  24370 , as illustrated in  FIG. 188 . In various embodiments, the cutting die  24935 , and/or any other suitable die, can comprise one or more heating elements, for example, which can be configured to seal the ends and/or edges of the tissue thickness compensators  24320 . In at least one embodiment, the tube  24324  can be filled with one or more fluids. In such embodiments, the cutting blades  24396  can be configured to incise the tube  24324  and, at the same time, seal the ends of the tube portions contained within the tissue thickness compensator  24320 . Thereafter, the plurality of staple cartridges  24300  can be removed from the mold. 
     In various embodiments, referring now to  FIGS. 190 and 191 , a staple cartridge  24400  can comprise a cartridge body  24410  which can be configured to removably store a plurality of staples therein. In addition, the staple cartridge  24400  can further comprise a tissue thickness compensator  24420 . In at least one embodiment, the tissue thickness compensator  24420  can include a compensator body comprised of a plurality of layers  24422  wherein, in various embodiments, the layers  24422  can be comprised of cellulose film, for example. As illustrated in  FIG. 192 , in various embodiments, a material  24424  can be positioned between two or more adjacent layers  24422  wherein the material  24424  can space the adjacent layers  24422  apart from each other. In at least one embodiment, the material  24424  can comprise a polyblend biomedics extrusion and, in various embodiments, the material  24424  can comprise a haemostatic material, an anti-inflammatory material, and/or an anti-biotic material, for example. In certain embodiments, referring now to  FIG. 192 , the material  24424  can be applied to a layer  24422  by a dispenser  24490  in a wave pattern, for example, wherein the wave pattern can be configured such that the material  24424  can be positioned over one or more staple cavities defined in the cartridge body  24410 . In such embodiments, the material  24424  can be captured within staples ejected from the staple cavities and provide a resilient biasing force to tissue also captured within the staples. In any event, one or more of the layers  24422  can be vacuum formed and/or heat sealed, for example, over the material  24424  to create the tissue thickness compensator  24420 . In certain embodiments, the tissue thickness compensator  22420  can then be cut to length. Various embodiments are envisioned in which a tissue thickness compensator  22420  is positioned against the deck surface of a staple cartridge and another tissue thickness compensator  22420  is positioned against the anvil. 
     In certain embodiments, referring now to  FIG. 195 , a staple cartridge  24600  can comprise one or more tissue thickness compensators  24620  positioned over a cartridge body  24610 . Referring primarily to  FIG. 194 , each tissue thickness compensator  24620  can comprise a plurality of layers  24622  and a compressible, or collapsible, member  24624  positioned between the layers  24622 . In various embodiments, the collapsible member  24624  can comprise a corrugated member which includes a plurality of pockets defined therein wherein, in at least one embodiment, one or more medicaments can be stored within the pockets. In at least one such embodiment, a first medicament can be placed within the pockets on a first side of the corrugated member and a second medicament can be placed within the pockets on a second side of the corrugated member, for example. In certain embodiments, the tissue thickness compensator  24620  can be formed when the layers  24622  and the compressible member  24624  are compressed together by rollers  24590 , for example. With reference now to an embodiment depicted in  FIG. 193 , a tissue thickness compensator  24520  can be formed from a tube of material that is rolled into a partially flattened shape by rollers  24590 , for example. In various embodiments, referring now to  FIGS. 196 and 197 , staples  21330  positioned within the cartridge body  24610  can be ejected therefrom such that the staples  21330  can capture at least a portion of a tissue thickness compensator  24620  therein. In such embodiments, the compressible member  24624  can be configured to apply a resilient biasing force against the tissue T which has also been captured within the staples  21330 . In various embodiments, the layers  24622  of the tissue thickness compensator  24620  can also be configured to apply a resilient biasing force against the tissue T. In certain embodiments, the staples  21330  can puncture the pockets of the corrugated member  24624  and release the one or more medicaments contained therein. 
     The tissue thickness compensators described above may include substances therein. The substances may include coagulants, medications, and/or anti-inflammatories, for example. The substances may be liquids, but also may take other forms, such as solids and/or gels, for example. For surgical devices that include such tissue thickness compensators, it may be advantageous for the surgical device to include features that direct the substance out of the tissue thickness compensators. For example, the substance may be directed from the tissue thickness compensators toward incised and stapled tissue. In another example, a first tissue thickness compensator may include a first substance and a second thickness compensator may include a second substance, wherein the first and second substances may be mixed by the surgical device. As another example, the substances may be directed away from each other, toward a staple cartridge, and/or toward an anvil of the surgical device, for example. 
       FIGS. 61 and 62  illustrate a surgical stapling system that includes a cutting blade  19000  comprising a cutting edge  19016 , a staple cartridge  19002 , an anvil  19008 , a first tissue thickness compensator  19004  positioned on the staple cartridge  19002 , and a second tissue thickness compensator  19006  positioned on the anvil  19008 . In use, the cutting blade  19000  is moved distally in the direction of arrow D to cut patient tissue T and the first and second tissue thickness compensators  19004  and  19006 . In various embodiments, the first tissue thickness compensator  19004  comprises a substance S contained therein and the second tissue thickness compensator  19006  comprises a substance S′ contained therein. In various embodiments, the first tissue thickness compensator  19004  includes an encasement that includes the substance S therein. The encasement may include a film of material that is opened by the cutting blade  19000  cutting the film, wherein the substance S is released when the film is opened. The second tissue thickness compensator  19006  may include a similar encasement, and the second substance S′ may be released when the encasement of the second tissue thickness compensator  19006  is cut open by the cutting blade  19000 . As the blade  19000  moves distally, guides  19030  and  19022  may direct or displace substances S and S′ from the first and second tissue thickness compensators  19004  and  19006 , respectively. For example, substances S and S′ may be directed toward the incised tissue T. The blade  19000  may be coupled to a shaft  19012 , which, in turn, may be connected to an actuating mechanism that moves the blade  19000  in the distal direction D and in a proximal direction indicated by arrow P. 
     A guide  19030  may direct the substance S from the first tissue thickness compensator  19004  towards the incised tissue T. A mirror-image of the guide  19030  may be positioned on an opposing face of the blade  19000 . Guide  19030  may include two raised ridges  19032  and  19034  that define a channel C therebetween. A distal end  19035  of the channel C can be positioned proximate to the first tissue thickness compensator  19004  and a proximal end  19037  of the channel C can be positioned proximate to the tissue T when the surgical stapler is positioned against the tissue T. In use, as the cutting blade  19000  moves in the distal direction D, the substance S from the first tissue thickness compensator  19004  enters the channel C at distal end  19035 , flows through the channel C, and exits the channel C at proximal end  19037  proximate to the tissue T. 
     A guide  19022  may direct substance S′ from the second tissue thickness compensator  19006  toward the incised tissue T. Guide  19022  includes a protrusion  19025  with an inclined surface  19023 . As shown in  FIG. 61 , the protrusion  19025  may pierce or cut the second tissue thickness compensator  19006  to release the substance S′. As the blade  19000  moves distally D, the inclined surface  19025  can direct the substance S′ towards the tissue T. 
     Substances S and S′ may mix as they are directed towards the tissue T. The substances S and S′ may be different and may react when mixed. For example, substances S and S′ may react chemically when mixed to form a new substance S″. The new substance S″ may be, for example, a medication, an antibiotic, a coagulant, and/or any other suitable type of substance. After the blade  19000  has been suitably advanced in the distal direction D, the blade  19000  may return by moving proximally P wherein the proximal movement of the blade  19000  may further mix substances S and S′. 
     Alternatively, the guides  19022  and  19030  may be configured to direct substances S and S′ away from tissue T. For example, guide  19030  may be configured to direct substance S toward the staple cartridge  19002 , and guide  19022  may be configured to direct substance S′ toward the anvil  19008 . Such an arrangement may be advantageous, for example, if the first tissue thickness compensator  19004  is held to the staple cartridge  19002  by an adhesive at a junction  19005 , for example, and if the second tissue thickness compensator  19906  is held to the anvil  19008  by an adhesive at a junction  19007 , for example. The substances S and S′ may dissolve or neutralize the adhesives, thereby at least partially releasing the first and second tissue thickness compensators  19004  and  19006  from the staple cartridge  19002  and the anvil  19008 , respectively. 
       FIG. 63  shows an alternative guide  19030 ′ in which a channel C′ is defined by a depression or groove in the surface of the blade  19014 . The channel C′ may comprise a single channel or may comprise multiple channels. 
       FIGS. 64-67  illustrate another surgical stapling system that includes a cutting blade  19060  and a cutting edge  19056 , a first tissue thickness compensator  19004 , and a second tissue thickness compensator  19006 . The blade  19060  may include a first protrusion  19062  on a first side of the blade  19060 , wherein the first protrusion  19062  defines an orifice  19064  passing from the first side of the blade  19060  to a second side of the blade  19060 . In various embodiments, the first protrusion  19062  and first orifice  19064  may be aligned with the first tissue thickness compensator  19004 . In use, as the blade  19060  moves distally, at least a portion of the substance S in the first tissue thickness compensator  19004  can pass through the first orifice  19064 . In various embodiments, contours of the first protrusion  19062  can direct the substance S to a second side of the blade  19060  and/or toward the tissue T. 
     The blade  19060  may also include a second protrusion  19066  on the second side of the blade  19060 , wherein the second protrusion defines an orifice  19068  passing from the second side of the blade  19060  to the first side of the blade  19060 . In various embodiments, the second protrusion  19066  and the second orifice may be aligned with the second tissue thickness compensator  19006 . In use, as the blade  19060  moves distally, at least a portion of the substance S′ in the tissue thickness compensator  19006  can pass through the second orifice  19068 . In various embodiments, contours of the second protrusion  19066  can direct the substance S′ to the first side of the blade  19060  and/or toward the tissue T. 
     Referring primarily to  FIGS. 64 and 65 , the shaft  19059  may include surface features, such as, for example, dimples  19070  that can increase turbulence and/or displacement of the substances S and S′. This increased turbulence and/or displacement can cause a greater portion of the substances S and S′ to come into contact with each other, for example. In at least one embodiment, the dimples  19070  can be positioned proximally with respect to the orifices  19064  and  19068 . When the blade  19000  is being advanced distally, the dimples  19070  can be downstream of the orifices  19064  and  19068 ; however, when the blade  19000  is refracted proximally, the dimples  19070  can be upstream of the orifices  19064  and  19068 . 
       FIGS. 68-70  illustrate another surgical stapler that includes a blade  19100  and a cutting edge  19108 , a first tissue thickness compensator  19120 , and a second tissue thickness compensator  19122 . In various embodiments, the first tissue thickness compensator  19120  can comprise a first substance S and a second substance S′. For example, the first substance S can be contained in a first encasement, described above. The second substance S′ can be carried in a second encasement that can be proximate to and/or surrounding the first encasement. In various embodiments, the second tissue thickness compensator  19122  can comprise a third substance S″. In various embodiments, the second tissue thickness compensator  1922  can comprise a fourth substance S′″. The third substance S″ and the fourth substance S′″ may be carried in encasements, like the encasements described above. The blade  19100  may include a textured surface  19110  on a first side  19102  of the blade  19100  on which substances S, S′, S″, and S′″ can spread across. Another textured surface may be located on an opposing second side (not shown) of the blade  19100 . The textured surface  19110  may comprise a series of disrupting features, such as, for example, grooves that are cut, scored, etched, and/or otherwise formed in the first surface  19102 . The disrupting features also may comprise a series of raised features, such as raised ridges, on the first surface  19102 , for example. As shown in  FIGS. 68-70 , the disrupting features of the textured surface  19110  may include a regularly repeating pattern of disrupting features. The disrupting features may also be placed in a non-repeating pattern or randomly placed. 
     The blade  19100  may also include a second surface  19104  that is positioned proximally relative to the first surface  19102 . In various embodiments, the second surface  19104  can be raised relative to the first surface  19102 . A junction between the first surface  19102  and the second surface  19104  can define a third surface  19106 , wherein the third surface  19106  may be positioned at an angle relative to a longitudinal axis of the blade  19100 . In various embodiments, the motion of the blade  19100  in the distal direction D can result in a first end  19107  of the third surface  19106  leading ahead of a second end  19109  of the third surface  19106 . As a result, as shown in  FIG. 70 , the third surface  19106  can cause the substances S and S′ from the first tissue thickness compensator  19120  to be directed toward the incised tissue T. A surface  19105 , similar to the second surface  19104 , may be located on the opposing second side of the blade  19100 . 
     The blade  19100  shown in  FIGS. 68-70  may be used in a surgical device that includes the first and second tissue thickness compensators  19004  and  19006  shown in  FIGS. 61-67 . As described above, the textured surface  19110  may distribute the substances S and S′ from respective tissue thickness compensators  19004  and  19006  on the first surface  19102  of the blade such that they may mix and can be positioned near the tissue T. 
     The blade  19100  shown in  FIGS. 68-70  also may be used in a surgical device that includes the first tissue thickness compensator  19120  and the second tissue thickness compensator  19122  shown in  FIGS. 68-70 . The first tissue thickness compensator  19120  may include an interior portion  19121  that includes a first substance S. When the first tissue thickness compensator  19120  is cut by the cutting edge  19108  of the blade  19100 , the substance S can be released from the interior portion  19121 . As the blade  19100  moves relative to the tissue thickness compensator  19120 , the substance S may be spread on the textured surface  19110  and the third surface  19106  can direct the substance S toward the tissue T. As described above, in various embodiments, the first tissue thickness compensator  19120  may include a second substance S′ outside of the interior portion  19121 . When the first tissue thickness compensator  19120  is cut by the cutting edge  19108  of the blade  19100 , both the first substance S and the second substance S′ may be distributed on the textured surface  19110 . The distribution on the textured surface  19110  may cause the first substance S and the second substance S′ to mix. When mixed, the first substance S and the second substance S′ may react, such as, for example, chemically reacting to form a new substance. The third surface  19106  may direct the first substance S and the second substance S′ towards the tissue. As described above, in various embodiments, the second tissue thickness compensator  19122  may include a third substance S″. When the second tissue thickness compensator  19122  is cut by the cutting edge  19108  of the blade  19100 , the third substance S″ may be distributed on the textured surface  19110  where it may mix with the first substance S and/or the second substance S′ and be directed towards the tissue T. As described above, in various embodiments, the second tissue thickness compensator  19122  may include a fourth substance S′″. When the second tissue thickness compensator  19122  is cut by the cutting edge  19108  of the blade  19100 , the third substance S″ and the fourth substance S′″ may be distributed on the textured surface  19110  where they may mix with the first substance S, the second substance S′ and/or each other and can be directed towards the tissue T. 
     In various embodiments, further to the above, a tissue thickness compensator can be comprised of a biocompatible material. The biocompatible material, such as, a foam, may comprise tackifiers, surfactants, fillers, cross-linkers, pigments, dyes, antioxidants and other stabilizers and/or combinations thereof to provide desired properties to the material. In certain embodiments, a biocompatible foam may comprise a surfactant. The surfactant may be applied to the surface of the material and/or dispersed within the material. Without wishing to be bound to any particular theory, the surfactant applied to the biocompatible material may reduce the surface tension of the fluids contacting the material. For example, the surfactant may reduce the surface tension of water contacting the material to accelerate the penetration of water into the material. In various embodiments, the water may act as a catalyst. The surfactant may increase the hydrophilicity of the material. 
     In various embodiments, the surfactant may comprise an anionic surfactant, a cationic surfactant, and/or a non-ionic surfactant. Examples surfactants include, but are not limited to polyacrylic acid, methalose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxy ethyl cellulose, carboxy methyl cellulose, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether, dialkylphenoxy poly(ethyleneoxy) ethanol, and polyoxamers, and combinations thereof. In at least one embodiment, the surfactant may comprise a copolymer of polyethylene glycol and polypropylene glycol. In at least one embodiment, the surfactant may comprise a phospholipid surfactant. The phospholipid surfactant may provide antibacterial stabilizing properties and/or disperse other materials in the biocompatible material. 
     In various embodiments, the tissue thickness compensator may comprise at least one medicament. The tissue thickness compensator may comprise one or more of the natural materials, non-synthetic materials, and/or synthetic materials described herein. In certain embodiments, the tissue thickness compensator may comprise a biocompatible foam comprising gelatin, collagen, hyaluronic acid, oxidized regenerated cellulose, polyglycolic acid, polycaprolactone, polyactic acid, polydioxanone, polyhydroxyalkanoate, poliglecaprone, and combinations thereof. In certain embodiments, the tissue thickness compensator may comprise a film comprising the at least one medicament. In certain embodiments, the tissue thickness compensator may comprise a biodegradable film comprising the at least one medicament. In certain embodiments, the medicament may comprise a liquid, gel, and/or powder. In various embodiments, the medicaments may comprise anticancer agents, such as, for example, cisplatin, mitomycin, and/or adriamycin. 
     In various embodiments, the tissue thickness compensator may comprise a biodegradable material to provide controlled elution of the at least one medicament as the biodegradable material degrades. In various embodiments, the biodegradable material may degrade may decompose, or loses structural integrity, when the biodegradable material contacts an activator, such as, for example an activator fluid. In various embodiments, the activator fluid may comprise saline or any other electrolyte solution, for example. The biodegradable material may contact the activator fluid by conventional techniques, including, but not limited to spraying, dipping, and/or brushing. In use, for example, a surgeon may dip an end effector and/or a staple cartridge comprising the tissue thickness compensator comprising the at least one medicament into an activator fluid comprising a salt solution, such as sodium chloride, calcium chloride, and/or potassium chloride. The tissue thickness compensator may release the medicament as the tissue thickness compensator degrades. In certain embodiments, the elution of the medicament from the tissue thickness compensator may be characterized by a rapid initial elution rate and a slower sustained elution rate. 
     In various embodiments, a tissue thickness compensator, for example, can be comprised of a biocompatible material which may comprise an oxidizing agent. In various embodiments, the oxidizing agent may an organic peroxide and/or an inorganic peroxide. Examples of oxidizing agents may include, but are not limited to, hydrogen peroxide, urea peroxide, calcium peroxide, and magnesium peroxide, and sodium percarbonate. In various embodiments, the oxidizing agent may comprise peroxygen-based oxidizing agents and hypohalite-based oxidizing agents, such as, for example, hydrogen peroxide, hypochlorous acid, hypochlorites, hypocodites, and percarbonates. In various embodiments, the oxidizing agent may comprise alkali metal chlorites, hypochlorites and perborates, such as, for example, sodium chlorite, sodium hypochlorite and sodium perborate. In certain embodiments, the oxidizing agent may comprise vanadate. In certain embodiments, the oxidizing agent may comprise ascorbic acid. In certain embodiments, the oxidizing agent may comprise an active oxygen generator. In various embodiments, a tissue scaffold may comprise the biocompatible material comprising an oxidizing agent. 
     In various embodiments, the biocompatible material may comprise a liquid, gel, and/or powder. In certain embodiments, the oxidizing agent may comprise microparticles and/or nanoparticles, for example. For example, the oxidizing agent may be milled into microparticles and/or nanoparticles. In certain embodiments, the oxidizing agent may be incorporated into the biocompatible material by suspending the oxidizing agent in a polymer solution. In certain embodiments, the oxidizing agent may be incorporated into the biocompatible material during the lyophylization process. After lyophylization, the oxidizing agent may be attached to the cell walls of the biocompatible material to interact with the tissue upon contact. In various embodiments, the oxidizing agent may not be chemically bonded to the biocompatible material. In at least one embodiment, a percarbonate dry power may be embedded within a biocompatible foam to provide a prolonged biological effect by the slow release of oxygen. In at least one embodiment, a percarbonate dry power may be embedded within a polymeric fiber in a non-woven structure to provide a prolonged biological effect by the slow release of oxygen. In various embodiments, the biocompatible material may comprise an oxidizing agent and a medicament, such as, for example, doxycycline and ascorbic acid. 
     In various embodiments, the biocompatible material may comprise a rapid release oxidizing agent and/or a slower sustained release oxidizing agent. In certain embodiments, the elution of the oxidizing agent from the biocompatible material may be characterized by a rapid initial elution rate and a slower sustained elution rate. In various embodiments, the oxidizing agent may generate oxygen when the oxidizing agent contacts bodily fluid, such as, for example, water. Examples of bodily fluids may include, but are not limited to, blood, plasma, peritoneal fluid, cerebral spinal fluid, urine, lymph fluid, synovial fluid, vitreous fluid, saliva, gastrointestinal luminal contents, and/or bile. Without wishing to be bound to any particular theory, the oxidizing agent may reduce cell death, enhance tissue viability and/or maintain the mechanical strength of the tissue to tissue that may be damaged during cutting and/or stapling. In various embodiments, the biocompatible material may comprise at least one microparticle and/or nanoparticle. The biocompatible material may comprise one or more of the natural materials, non-synthetic materials, and synthetic materials described herein. In various embodiments, the biocompatible material may comprise particles having a mean diameter of about 10 nm to about 100 nm and/or about 10 μm to about 100 μm, such as, for example, 45-50 nm and/or 45-50 μm. In various embodiments, the biocompatible material may comprise biocompatible foam comprising at least one microparticle and/or nanoparticle embedded therein. The microparticle and/or nanoparticle may not be chemically bonded to the biocompatible material. The microparticle and/or nanoparticle may provide controlled release of the medicament. In certain embodiments, the microparticle and/or nanoparticle may comprise at least one medicament. In certain embodiments, the microparticle and/or nanoparticle may comprise a hemostatic agent, an anti-microbial agent, and/or an oxidizing agent, for example. In certain embodiments, the tissue thickness compensator may comprise a biocompatible foam comprising an hemostatic agent comprising oxidized regenerated cellulose, an anti-microbial agent comprising doxycline and/or Gentamicin, and/or an oxidizing agent comprising a percarbant. In various embodiments, the microparticle and/or nanoparticle may provide controlled release of the medicament up to three days, for example. 
     In various embodiments, the microparticle and/or nanoparticle may be embedded in the biocompatible material during a manufacturing process. For example, a biocompatible polymer, such as, for example, a PGA/PCL, may contact a solvent, such as, for example, dioxane to form a mixture. The biocompatible polymer may be ground to form particles. Dry particles, with or without ORC particles, may be contacted with the mixture to form a suspension. The suspension may be lyophilized to form a biocompatible foam comprising PGA/PCL having dry particles and/or ORC particles embedded therein. 
     In various embodiments, the tissue thickness compensators or layers disclosed herein can be comprised of an absorbable polymer, for example. In certain embodiments, a tissue thickness compensator can be comprised of foam, film, fibrous woven, fibrous non-woven PGA, PGA/PCL (Poly(glycolic acid-co-caprolactone)), PLA/PCL (Poly(lactic acid-co-polycaprolactone)), PLLA/PCL, PGA/TMC (Poly(glycolic acid-co-trimethylene carbonate)), PDS, PEPBO or other absorbable polyurethane, polyester, polycarbonate, Polyorthoesters, Polyanhydrides, Polyesteramides, and/or Polyoxaesters, for example. In various embodiments, a tissue thickness compensator can be comprised of PGA/PLA (Poly(glycolic acid-co-lactic acid)) and/or PDS/PLA (Poly(p-dioxanone-co-lactic acid)), for example. In various embodiments, a tissue thickness compensator can be comprised of an organic material, for example. In certain embodiments, a tissue thickness compensator can be comprised of Carboxymethyl Cellulose, Sodium Alginate, Cross-linked Hyaluronic Acid, and/or Oxidized regenerated cellulose, for example. In various embodiments, a tissue thickness compensator can comprise a durometer in the 3-7 Shore A (30-50 Shore OO) ranges with a maximum stiffness of 15 Shore A (65 Shore 00), for example. In certain embodiments, a tissue thickness compensator can undergo 40% compression under 3 lbf load, 60% compression under 6 lbf load, and/or 80% compression under 20 lbf load, for example. In certain embodiments, one or more gasses, such as air, nitrogen, carbon dioxide, and/or oxygen, for example, can be bubbled through and/or contained within the tissue thickness compensator. In at least one embodiment, a tissue thickness compensator can comprise beads therein which comprise between approximately 50% and approximately 75% of the material stiffness comprising the tissue thickness compensator. 
     In various embodiments, a tissue thickness compensator can comprise hyaluronic acid, nutrients, fibrin, thrombin, platelet rich plasma, Sulfasalazine (Azulfidine®−5ASA+Sulfapyridine diazo bond))−prodrug−colonic bacterial (Azoreductase), Mesalamine (5ASA with different prodrug configurations for delayed release), Asacol® (5ASA+Eudragit-S coated−pH&gt;7 (coating dissolution)), Pentasa® (5ASA+ethylcellulose coated−time/pH dependent slow release), Mesasal® (5ASA+Eudragit-L coated−pH&gt;6), Olsalazine (5ASA+5ASA−colonic bacterial (Azoreductase)), Balsalazide (5ASA+4-Aminobenzoyl-B-alanine)-colonic bacterial (Azoreductase)), Granulated mesalamine, Lialda (delay and SR formulation of mesalamine), HMPL-004 (herbal mixture that may inhibit TNF-alpha, interleukin-1 beta, and nuclear-kappa B activation), CCX282-B (oral chemokine receptor antagonist that interferes with trafficking of T lymphocytes into the intestinal mucosa), Rifaximin (nonabsorbable broad-spectrum antibiotic), Infliximab, murine chymieric (monoclonal antibody directed against TNF-alpha-approved for reducing signs/symptoms and maintaining clinical remission in adult/pediatric patients with moderate/severe luminal and fistulizing Crohn&#39;s disease who have had inadequate response to conventional therapy), Adalimumab, Total Human IgG1 (anti-TNF-alpha monoclonal antibody—approved for reducing signs/symptoms of Crohn&#39;s disease, and for the induction and maintenance of clinical remission in adult patients with moderate/severe active Crohn&#39;s disease with inadequate response to conventional therapies, or who become intolerant to Infliximab), Certolizumab pegoll, humanized anti-TNF FAB′ (monoclonal antibody fragment linked to polyethylene glycol—approved for reducing signs/symptoms of Crohn&#39;s disease and for the induction and maintenance of response in adult patients w/moderate/severe disease with inadequate response to conventional therapies), Natalizumab, First non-TNF-alpha inhibitor (biologic compound approved for Crohn&#39;s disease), Humanized monoclonal IgG4 antibody (directed against alpha-4 integrin—FDA approved for inducing and maintaining clinical response and remission in patients with moderate/severe disease with evidence of inflammation and who have had inadequate response to or are unable to tolerate conventional Crohn&#39;s therapies and inhibitors of TNF-alpha), concomitant Immunomodulators potentially given with Infliximab, Azathioprine 6-Mercaptopurine (purine synthesis inhibitor—prodrug), Methotrexate (binds dihydrofolate reductase (DHFR) enzyme that participates in tetrahydrofolate synthesis, inhibits all purine synthesis), Allopurinol and Thioprine therapy, PP1, H2 for acid suppression to protect the healing line, C-Diff-Flagyl, Vancomycin (fecal translocation treatment; probiotics; repopulation of normal endoluminal flora), and/or Rifaximin (treatment of bacterial overgrowth (notably hepatic encephalopathy); not absorbed in GI tract with action on intraluminal bacteria), for example. 
     As described herein, a tissue thickness compensator can compensate for variations in the thickness of tissue that is captured within the staples ejected from a staple cartridge and/or contained within a staple line, for example. Stated another way, certain staples within a staple line can capture thick portions of the tissue while other staples within the staple line can capture thin portions of the tissue. In such circumstances, the tissue thickness compensator can assume different heights or thicknesses within the staples and apply a compressive force to the tissue captured within the staples regardless of whether the captured tissue is thick or thin. In various embodiments, a tissue thickness compensator can compensate for variations in the hardness of the tissue. For instance, certain staples within a staple line can capture highly compressible portions of the tissue while other staples within the staple line can capture portions of the tissue which are less compressible. In such circumstances, the tissue thickness compensator can be configured to assume a smaller height within the staples that have captured tissue having a lower compressibility, or higher hardness, and, correspondingly, a larger height within the staples that have captured tissue having a higher compressibility, or lower hardness, for example. In any event, a tissue thickness compensator, regardless of whether it compensates for variations in tissue thickness and/or variations in tissue hardness, for example, can be referred to as a ‘tissue compensator’ and/or as a ‘compensator’, for example. 
     The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. 
     Preferably, the invention described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility. 
     Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. 
     While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.