Patent Publication Number: US-9421013-B2

Title: Surgical Fastening Apparatus

Description:
This application is a continuation of U.S. application Ser. No. 12/899,651 filed Oct. 7, 2010, now U.S. Pat. No. 8,430,292, which claims priority from provisional application Ser. No. 61/326,292, filed Apr. 21, 2010 and priority from provisional application Ser. No. 60/255,529, filed Oct. 28, 2009. The entire contents of each of these applications are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a surgical fastening apparatus and, more particularly, to a surgical fastening apparatus having a fastener and retainer system. 
     2. Background of the Related Art 
     Various types of surgical stapling instruments for performing a circular anastomosis are well known, wherein an operator actuates the apparatus at a location which is relatively remote from the location at which the circular anastomosis takes place. Anastomosis is the surgical joining of separate hollow organ sections. Typically, an anastomosis procedure involves surgery in which a diseased or defective section of hollow tissue is removed. 
     A conventional surgical stapling instrument for performing a circular anastomosis in a hemorrhoidal or other surgical procedure generally includes a shell assembly having an annular array of staples and staple slots and an anvil assembly having a circular array of staple forming pockets in a proximal surface thereof. An example of surgical stapling instruments for performing circular anastomosis is described in U.S. Pat. Nos. 7,168,604, 7,303,106 and pending U.S. application Ser. No. 12/550,443, filed Aug. 31, 2009, all of which are incorporated herein in their entirety by reference. Typically, the anvil assembly is longitudinally movable from an open position to a closed position which places the anvil assembly adjacent to the shell assembly to clamp the body tissue therebetween. After bringing the anvil and shell assemblies to a closed position to clamp tissue, an annular pusher including a plurality of pushers which are configured to eject a corresponding staple from the staple slot through the tissue and against a receiving pocket of the anvil to form staples is actuated by the operator in a relatively remote region to perform a circular anastomosis. After stapling the tissues together, the tissue is severed by the annular blade and extracted. 
     Surgical fastening instruments applying two part surgical fasteners are known. In these instruments, a plurality of retainers are supported in an anvil assembly and a plurality of fasteners are supported in a fastener holding assembly. The fasteners are advanced through tissue and into engagement with openings in respective retainers. These two part fasteners are typically composed of resorbable material. The firing force of the fasteners in some of these instruments could shift the retainers out of position which may result in misalignment. In addition, the retainers may slip against the anvil and/or may come off the anvil before firing which may also result in misalignment. Accordingly, it would be advantageous to provide a configuration which enhances mating of the fasteners and the retainers and it may be useful to provide such configuration in a circular anastomosis instrument. 
     Additionally, the thickness of the clamped tissue can vary in different regions. Therefore, it would be advantageous to provide a fastener-retainer configuration which can accommodate such varying tissue thickness. 
     SUMMARY 
     In accordance with one aspect of the present disclosure, a surgical fastening apparatus is provided including a fastener receiving frame including a plurality of spaced apart openings formed therein and a fastener supporting member having a plurality of spaced apart surgical fasteners extending therefrom. The surgical fasteners are engagable with the plurality of openings to mate with the fastener receiving frame to fasten tissue therebetween, the fasteners engageable with the openings in a plurality of positions dependent on a tissue thickness between the fastener receiving frame and the fastener supporting member. 
     The fastener receiving frame is preferably detachably secured to a supporting structure of the surgical apparatus. Preferably, a pusher advances the fastener supporting member into engagement with the fastener receiving frame. 
     In a preferred embodiment, the pusher is an annular pusher and the fastener supporting member includes an annular supporting frame. Preferably, an annular blade advanceable by the annular pusher to sever tissue is provided. 
     In some embodiments, the fasteners each have a series of locking tabs spaced axially along the fasteners to mate with the respective opening in the fastener receiving frame at various positions to provide a variable depth of engagement. In some embodiments, the openings can have a series of locking surfaces to engage the respective fastener at various positions to provide a variable depth of engagement. In one embodiment, the locking tabs include a plurality of substantially semi-circular ribs. In one embodiment, the locking tabs include a plurality of projections angled to enable movement of the fastener in a first direction toward the opening in the fastener receiving frame and prevent movement of the fastener in a second opposite direction away from the opening. The fasteners can include a longitudinally extending slot formed therein. 
     The fastener can include a reservoir to receive a drug. 
     In some embodiments, the opening in the fastener receiving frame has a first depth and the respective fastener has a first length, wherein the first length is less than the first depth. 
     In another aspect, the present disclosure provides a surgical fastening apparatus comprising a fastener receiving frame including a plurality of spaced apart openings formed therein and a fastener supporting member containing a plurality of spaced apart surgical fasteners extending therefrom. The surgical fasteners are engagable with the plurality of openings to mate with the fastener receiving frame to fasten tissue therebetween. The fasteners and openings are configured to allow locking engagement of the fasteners in the openings at two or more depths of the fastener, the depth of the fastener preselected prior to advancement of the fasteners into the openings. 
     Preferably, the fastener receiving frame is detachably secured to a supporting structure of the surgical apparatus and a substantially annular pusher advances the fastener supporting member into engagement with the fastener receiving frame. In preferred embodiments, the fastener supporting member and fastener receiving frame are substantially annular. The fasteners can include a series of locking tabs spaced axially along a length of the fastener. 
     In one embodiment, the surgical fastening apparatus includes a sensor positioned at a distal portion to determine a tissue parameter to send a signal to determine the extent of advancement of the fastener supporting member. In another embodiment, the surgical fastening apparatus includes a sensor positioned at the distal portion to determine an apparatus parameter to send a signal to determine the extent of advancement of the fastener supporting member. 
     The fastener receiving frame, fastener supporting member and/or plurality of fasteners can be made of biodegradable polymer. The fastener receiving frame and/or fastener supporting member can be elastic to provide flexibility. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects and features of the present disclosure will become apparent from the following description of embodiments given in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a surgical fastening apparatus in accordance with an embodiment of the present disclosure; 
         FIG. 2  is a perspective view of the end effector of  FIG. 1 ; 
         FIG. 3  is an enlarged perspective view of detail area “ 3 ” of  FIG. 2 ; 
         FIG. 4  is an enlarged perspective view of detail area “ 4 ” of  FIG. 2 ; 
         FIG. 5  is a perspective view of the retainer and fastener assembly of  FIG. 1 ; 
         FIG. 6  is an exploded view of the end effector of  FIG. 2 ; 
         FIG. 7  is a perspective view of a fastener in accordance with one embodiment of the present disclosure; 
         FIG. 8  is a perspective view of the retainer assembly and knife of the apparatus of  FIG. 1 ; 
         FIGS. 9-11  illustrate the movement of the fastener of  FIG. 7  into locking engagement with a retainer of the present disclosure; 
         FIG. 12  is a longitudinal cross-sectional view of the end effector of  FIG. 1 ; 
         FIG. 13  is an enlarged view of detail area “ 13 ” of  FIG. 12 ; 
         FIG. 14  is a front view illustrating the severing of the fastener retaining frame; 
         FIG. 15  is a perspective view of a fastener receiving frame and fastener supporting member of an alternate embodiment of the present disclosure; 
         FIG. 16  is a close up cross-sectional view of a portion of the fastener receiving frame and fastener supporting member showing their locking engagement; and 
         FIG. 17  is a perspective view of an alternate embodiment of the surgical fastening apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Various embodiments of the presently disclosed end effector will now be described in detail with reference to the drawings, wherein like references numerals identify similar or identical elements. In the drawings and in the description which follows, the term “proximal” will refer to the end of the component that is closer to the operator during use, while the term “distal” will refer to the end of the component that is further from the operator, as is traditional and conventional in the art. 
     With reference to  FIG. 1 , a surgical fastening apparatus  100  is illustrated. A suitable example of a surgical fastening apparatus  100  is disclosed in U.S. Pat. Nos. 7,168,604, 7,303,106 and pending U.S. application Ser. No. 12/550,443, filed Aug. 31, 2009, the entire contents of each are incorporated by reference herein. The surgical fastening apparatus  1000  includes a handle assembly  200 , an elongate shaft  300  extending distally therefrom, and an end effector  100  coupled to the distal end of the elongate shaft  300 . The length and the curvature of elongate shaft  300  may be tailored to meet the specific needs of surgical procedure being performed. Elongate shaft  300  alternatively may be flexible to facilitate maneuvering of surgical fastening apparatus  100 , more specifically, end effector  100 , to the targeted area in the body containing tissues to be joined. 
     The handle assembly  200  generally includes a stationary handle  240 , a pivotable trigger  210  and a rotatable knob  220 . When rotatable knob  220  is manually rotated, anvil assembly  20  will longitudinally translate in relation to shell assembly  10  between an open position and a closed position in a manner described below. Actuation of trigger  210  towards stationary handle  240  advances annular pusher  40  ( FIG. 6 ) distally within shell assembly  10  to eject fasteners from shell assembly  10  in a manner described below. Actuation of trigger  210  also longitudinally translates a knife  51  ( FIG. 6 ) that severs tissue as well as separates the formed fasteners from a retaining frame in a manner described below. 
     Referring now to  FIGS. 2 and 6 , an embodiment of the present disclosure is shown generally as staple end effector  100 . Staple end effector  100  includes an anvil assembly  20  and a shell assembly  10 . 
     Anvil assembly  20  includes an anvil  22 , fastener retaining frame  24 , and a flange member  16 . Flange member  16  is preferably composed of plastic material such as HDPE. As will be discussed in further detail below, fastener retaining frame  24  includes a plurality of perforations  26  and a plurality of retainers  28  ( FIGS. 2 and 8 ) and is detachably secured to flange member  16  which is fixedly attached to anvil  22 . Anvil shaft  25  extends from anvil  22  and can include a plurality of openings  29  for receipt of purse string suture such as described in detail in patent application Ser. No. 12/550,443, previously incorporated by reference herein in its entirety. 
     Shell assembly  10  accommodates therein a fastener guide member  30  which includes a plurality of axially extending and circumferentially arranged fastener slots  34  ( FIG. 6 ) for receiving therein a plurality of axially extending surgical fasteners  32  having distally directed tissue piercing prongs for mating with the plurality of retainers  28  on fastener retaining frame  24  to fasten tissue therebetween. Shell assembly  10  further accommodates therein an annular pusher  40  including a plurality of pusher fingers  42  operably associated with the plurality of surgical fasteners  32 . Each pusher  42  is configured for ejecting an associated surgical fastener  32  towards a corresponding retainer  28  on fastener retaining frame  24 . A distal end of a drive shaft is operably connected with annular pusher  40  and a proximal end of the drive shaft is operably connected with trigger  210 , whereby actuation of trigger  210  distally advances the drive shaft which advances annular pusher  40  within housing  45  of shell assembly  10  to eject surgical fasteners  32  from fastener guide member  30  in a manner described below. A circular knife  51  with an annular cutting blade is advanced by the pusher  40  to sever tissue in the manner described below. 
     With particular reference to  FIGS. 3 and 5 , fastener retaining frame  24  will be described in detail. Fastener retaining frame  24  includes a first annular portion  24   a  having a plurality of retainers  28  circumferentially disposed thereon and a second annular portion  24   b  having a plurality of circumferentially arranged perforations  26 . The two annular portions  24   a  and  24   b  are concentrically arranged, with the second annular portion  24   b  concentrically arranged within (radially inwardly) of the first annular portion  24   a . The plurality of retainers  28  are either monolithically formed or are individually formed and connected by suitable structures, e.g., links  23 , thereby forming a single body. Moreover, first annular portion  24   a  may be monolithically formed with second annular portion  24   b . The first annular portion  24   a  and the second annular portion  24   b  may be made of different materials, but in some embodiments they are made of biodegradable polymers (e.g. L4). For clarity, only a few of the retainers, perforations, etc. are labeled. 
     With reference still to  FIGS. 3 and 5 , each retainer  28  includes a bridge or backspan  27  and a pair of posts  29  each forming a cavity or opening  29   a  therein. Each retainer  28  is mated with an associated surgical fastener  32 . Specifically, each prong  33  ( FIG. 7 ) of the associated surgical fastener  32  is inserted into each cavity  29   a  of associated retainer  28 . Surgical fastener  32  and retainer  28  may be configured to engage in a snap-fit manner. This is described in detail below with reference to  FIGS. 9-11 . Furthermore, a tip  33   a  of each prong  33  may include a barb  34  to enhance secure mating with retainer  28 . Bridge or backspan  35  extends between prongs  33 . The plurality of retainers  28  circumferentially disposed on first annular portion  24   a  of fastener retaining frame  24  are arranged to define a ring of retainers  28 . The first annular portion  24   a  includes two rings of retainers  28  wherein each ring has  16  retainers, although a different number of retainers and/or a different number of rings are contemplated. When more than one ring of retainers  29  is present in first annular portion  24   a , retainers  28  forming one ring may be radially aligned with those forming another ring. Alternatively, retainers  28  forming one ring may have a partial overlap or be radially offset with those forming another ring. Retainers  28  may be substantially uniformly spaced apart; however, the spacing between retainers  28  may be tailored to meet the specific needs of the surgical operation being performed. The fasteners  32  and retainers  28  are preferably made of a resorbable material. 
     With reference still to  FIGS. 3, 5 and 8 , fastener retaining frame  24  includes a plurality of perforations  26  in second annular portion  24   b  thereof. The plurality of perforations  26  may be substantially uniformly formed (substantially uniformly spaced apart) in second annular portion  24   b . As an alternative to equidistant or substantially equidistant spacing, other spacing for the perforations  26  is also contemplated including perforations  26  arbitrarily defined or otherwise spaced. In one embodiment, the plurality of perforations  26  may define more than one ring of perforations. The diameter of each of the plurality of perforations  26  may be selected such that the thickness of the annular blade is less than the diameter of each of perforations  26 . Such configuration may facilitate severing or breaking off of the plurality of perforations  26 . In addition, each perforation  26  may include a radially notched portion configured to facilitate severing or breaking off of perforations  26  upon actuation of annular pusher  40 . Alternatively, each perforation  26  may include a pair of opposing slits also serving to facilitate breaking off of perforations  26  upon actuation of annular pusher  40 . When employing perforations  26  containing for example the pair of slits, the width of the slits may be chosen to correspond with the thickness of the annular blade to allow the annular blade to be engaged within the opposing slits of the associated perforation. In some embodiments, the thickness of second annular portion  24   b  defining the plurality of perforations  26  may be varied. For example, an inner part of the second annular portion  24   b , i.e., a part that is inside of the plurality of perforations  26 , can have a thickness less than that of an outer part of second annular portion  24   b , i.e., a part that is in contact with first annular portion  24   a , whereby the relatively thinner part or more brittle part can serve to facilitate breaking off of perforations  26  resulting in a detachment of fastener retaining frame  24  from flange member  16  as will be discussed below. In the alternative, the thickness of only a part defining the plurality of perforations  26  may be less than that of the rest of second annular portion  24   b  whereby such configuration also facilitates breaking off of the plurality of perforations  26  resulting in a detachment of fastener retaining frame  24  from flange member  16 . 
     Turning to  FIGS. 12 and 13 , anvil assembly  20  in a closed position prior to the firing of surgical fasteners  32  by the actuation of trigger  210  is illustrated. Flange member  16  has an annular recess  18  and includes a ledge  18   a  to form a supporting and/or retaining structure to fastener retaining frame  24 . Fastener retaining frame  24  is disposed in annular recess  18  and is secured therein by ledge  18   a .  FIG. 13  illustrates ledge  18   a  securing fastener retaining frame  24  at second annular portion  24   b . Accordingly, the thickness of the inner part of second annular portion  24   b  and/or the rigidity of second annular portion  24   b  may be chosen, e.g., by choosing the material having the requisite rigidity, to prevent bending of the mated fastener retaining frame  24  at perforations  26  and/or at a location in contact with ledge  18   a  prior to severing the plurality of perforations  26 . In one embodiment, a distal side of fastener retaining frame  24  is axially tapered with respect to the thickness thereof to enhance secure attachment thereof to annular recess  18  of flange member  16  also axially tapered with respect to the thickness thereof. Flange member  16  having fastener retaining frame  24  detachably secured thereto is fixedly attached to anvil  22  so that fastener retaining frame  24  and anvil  22  move as a single unit in an longitudinal translation thereof through a manual operation of the rotational knob  220  by the operator. 
     Still referring to  FIGS. 12 and 13 , shell assembly  10  accommodates fastener guide member  30  which contains a plurality of circumferentially arranged and axially extending fastener slots  39  for receiving therein a plurality of axially extending surgical fasteners  32  having tissue piercing prongs  33  for mating with plurality of retainers  28  on fastener retaining frame  24  to fasten body tissue therebetween.  FIGS. 12 and 13  illustrate a surgical fastener  32  loaded in fastener slot  34  and having a proximal side thereof engaged with an associated pusher  42  prior to being fired. 
     In use, anvil assembly  20  is spaced from shell assembly  10  as shown in  FIG. 1  such that the end effector is an open or unapproximated position. Once the body tissues to be fastened are placed in the open space between anvil assembly  20  and shell assembly  10 , anvil assembly  20  is translated proximally to an approximated position to clamp the body tissues therebetween such that the end effector is in a closed or approximated position. This is achieved by rotating the rotatable knob  220  of the handle assembly  200 . 
     The attachment of fastener retaining frame  24  to flange member  16 , which is fixedly attached to anvil  22 , reduces slippage of fastener retaining frame  24  against anvil  22  and retains its position with respect to anvil  22  during axial translations thereof. Once the clamping of the body tissues has taken place, the operator actuates trigger  210  which in turn distally drives the drive shaft connected to annular pusher  40 . The plurality of pushers  42  on the distally translated annular pusher  40  ejects the corresponding set of surgical fasteners  32  from fastener slots  34  of fastener guide member  30 . Each of the ejected set of surgical fasteners  32  pierce through the body tissue and are received into a corresponding retainer  28 . Specifically, a portion of each of the prongs of fasteners  32  is received into a respective cavity  29   a  formed in posts  29  in retainer  28 . This is shown in the fastener advancement steps of  FIGS. 9-11  wherein the tip  33  and barbs  34  of fastener prong  33  deform receiving walls  29   b  of posts  29  as the fastener prong  33  is forced through cavity  29   a  as shown in  FIG. 10 . After passage beyond receiving walls  29   b , the barbs  34  of fastener  32  engage ledge  29   c  of wall  29   b  to prevent retraction (proximal movement) of the fastener  32 , thereby locking the fastener  32  with the respective retainer  28 . 
     Note that since fastener retaining frame  24  is securely attached to flange member  16  which is fixedly attached to anvil  22 , slippage of fastener retaining frame  24  against anvil  22  due to the firing force produced by the actuation of trigger  210  which ejects the plurality of fasteners  32  from fastener slots  34  into the body tissues is reduced. Thus, the position of fastener retaining frame  24  is maintained with respect to anvil  22  during the firing of surgical fasteners  32 . Moreover, the plurality of retainers  28  are either monolithically formed or individually formed and connected by suitable structures, e.g., links, thereby forming a single body. In either instance, the configuration of the plurality of retainers  28  as a single body, in conjunction with fastener retaining frame  24  being secured to flange member  16  which is fixedly attached to anvil  22 , reduces the radial misalignment of surgical fasteners  32  with fastener retaining frame  24 . 
     As noted above, fastener retaining frame  24  and fastener guide member  30  may be configured to provide a plurality of rings of surgical fasteners  32  on tissue, e.g., two rings of surgical fasteners wherein each ring is defined by sixteen fasteners, to meet the needs of the specific procedure being performed. Upon mating of the plurality of surgical fasteners  32  with fastener retaining frame  24 , an annular blade  51  is actuated to distally translate through shell assembly  10 . Note the annular blade can be translatable by actuation of the trigger  210  which advances the fasteners, or alternatively by a separate actuator actuated in a separate step. The annular blade  51  comes into contact with fastener retaining frame  24  and is pressed against the plurality of perforations  26  defined in the fastener retaining frame  24  severing or breaking perforations  26 . This is illustrated in  FIG. 14  showing the broken fastener retaining frame  24  after the fasteners are applied through tissue T. The broken or severed perforations  26  enable the mated surgical fastener  32  and fastener retaining frame  24  to be detached from anvil  22 . The severing or breaking off of perforations  26  leaves a residuary ring, i.e., the inner part of second annular portion  24   b  of fastener retaining frame  24  (see  FIG. 14 ), within ledge  18   a  of annular recess  18  of flange member  16 . In some embodiments, in order to prevent perforation chips that may be produced during the severing or breaking off of perforations  26 , each of the plurality of perforations  26  may be provided with, for example, a pair of opposing slits or a notched portion, as mentioned above, wherein the thickness of the annular blade is chosen to be smaller than, e.g., the width of the pair of opposing slits. The mated surgical fastener  32  and fastener retaining frame  24  fastening body tissue therebetween would then be free to displace without being restricted or attached to anvil  22 . Actuation of the knife severs the tissue. The operator then moves anvil  22  to the open position by rotating the rotatable knob  220  of the handle assembly thereby distally translating anvil assembly  20 . After the removal of the severed tissue, e.g. hemorrhoidal tissue, surgical fastening device is extracted from the body. 
       FIGS. 15 and 16  illustrate an alternate embodiment of the present disclosure. An apparatus such as that of  FIG. 1  or in the patents/application referred to above and incorporated herein by reference can be utilized for approximation and fastener firing. A fastener receiving frame or plate  80  has a plurality of spaced apart openings  82  formed therein. The frame  80  is preferably substantially annular in configuration and the openings  82  are preferably substantially equidistantly spaced, although other frame shapes and different spacings of the openings are also contemplated. The frame  80  can be formed of an elastic material to provide some bending/flexibility of the frame  80 . The fastener receiving frame  80  is preferably composed of a bioabsorbable material. The fastener receiving frame  80  is preferably detachably secured to an anvil similar to anvil  22  of  FIG. 1  via engagement with a flange member similar to flange member  16  of  FIG. 6 . 
     A fastener supporting member or plate  90 , preferably substantially annular in configuration, contains a plurality of spaced apart fasteners  92  extending therefrom. The fasteners  92  are illustratively substantially equidistantly spaced along the frame  90  to correspond to the spacing of the openings  82  in frame  80 . It is contemplated that other spacings of the fasteners  92  and openings  82 , including non-uniform spacings, are also contemplated. 
     The fastener assembly of  FIGS. 15 and 16  is designed to enable engagement of the fasteners and frame  80  at various depths to accommodate different tissue thickness. One way this is achieved is by the series of axially spaced locking tabs  94  along the length of the fastener  92 . In the illustrated embodiment, four locking tabs  94  are shown spaced along the longitudinal axis of the fastener  92 , it being understood however, that a different number of locking tabs can be provided as well as different spacings, e.g. non-uniform spacings. As shown in  FIG. 16 , the locking tabs  94  extend radially from the fastener support member  90  and engage an internal wall  84  within opening  82 . In this manner, the fastener can mate with the frame  80  at various depths, depending on which tab  94  engages the ledge  84   a  of internal wall  84 . In  FIG. 16 , the second locking tab  94  (from the tip) is shown engaged. Fasteners  92  can also include a longitudinal slot  95  separating each fastener  92  into two identical half portions. In such structure, the locking tabs  94  are hemispherical shaped, with four on each fastener half. This provides for increased flexibility of the fastener  92  as it is inserted through opening  80  and past the internal wall  84  of the opening  82 . 
     The projecting surfaces, e.g. tabs  94 , can also have an angled surface  96  to enable movement of the fastener in a direction toward the frame  80  while the straight surface  97  prevents movement in a reverse direction (away from the fastener receiving frame  80 ). 
     In use, after the fastener receiving frame  80  and fastener supporting member  90  are approximated to clamp tissue therebetween by a knob such as rotatable knob  220  of  FIG. 1 , a pusher is actuated by a trigger such as trigger  210  of  FIG. 1 , to advance the fastener supporting member  90  distally as a unit to advance the fasteners  92  as a unit. 
     If thicker tissue is encountered, then the extent of penetration of the fasteners  92  into openings  82  will be less than if thicker tissue is encountered. This will enable fastening the two members  80 ,  90  without overcompressing tissue which can cause tissue trauma and other adverse effects. If thinner tissue is encountered, then the fasteners  92  can penetrate to a greater depth (level) within the respective opening  80 , thus providing secure engagement. 
     The fastener support frame  90  can be composed of an elastic material so that it can flex during application to tissue. In this manner, accommodation can be made for varying tissue thicknesses of the tissue clamped between frames  80  and  90 . For example, if a first region of the clamped tissue is thicker than a second region, the frame  90  can flex so that fasteners  92  adjacent the second region can penetrate a greater depth than fasteners  92  adjacent the first region and a different locking tab  94  can locking engage the wall  84 . Fastener receiving frame  80  can also be composed of an elastic material to provide bending/flexibility. 
     Although locking tabs are shown on the fasteners  92 , it is also contemplated that the openings  82  can be configured with tabs, walls or other structure at various “levels” to provide the locking structure. 
     An annular cutting blade, similar to blade  51  of  FIG. 6 , can be provided to sever tissue. 
     In alternative embodiments, the depth of the fasteners can be preset prior to firing the fasteners. That is, the fastener pusher would be preset to the distance of travel to accommodate the desired degree of advancement of the fastener supporting member and fasteners into the openings  82  of the fastener receiving frame  80 . Additionally, several pushers could be provided, e.g. arranged in quadrants or other regional separations, so that each of the pushers could be preset so that various pushers can be advanced to various depths. This can be achieved by placement of a sensor adjacent the end effector at the distal portion of the apparatus which can measure a tissue parameter, e.g. tissue thickness, and/or measure an end effector parameter at the distal portion of the apparatus, e.g. the gap between the fastener receiving frame  80  and fastener supporting frame  90  once approximated to clamp tissue therebetween. The sensor sends a signal to a controller which sends a signal to the pusher to control the extent of advancement of the pushers and thus the extent of advancement of fasteners  92  in response to the parameter determined by the sensor. For example, as shown in  FIG. 17 , apparatus  100 ′ is identical to apparatus  100  of  FIG. 1 , and corresponding parts are labeled with “prime” designations. Sensor S in this embodiment measures the gap between shell assembly  10 ′ and anvil assembly  20 ′ of end effector  100 ′, sending a signal (via wires internal of the shaft  300 ′) to controller C. Controller C sends a signal via the wire to the actuator within the handle assembly  200 ′ which sets the distal movement of the actuator in response to the measured parameter. Note that wireless transmissions are also contemplated. 
     The foregoing embodiments for the fastening receiving frame and fastening supporting frame can be used with the instrument of  FIG. 1  described above and in the instruments of U.S. Pat. Nos. 7,168,604, 7,303,106 and application Ser. No. 12/550,443, incorporated by reference hereinabove in their entirety. 
     The apparatus described herein can be used in various surgical procedures, including for example, hemorrhoid surgery. 
     From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. For example, the annular blade may be fixedly secured to the anvil and configured to break the plurality of perforations on the fastener retaining frame upon firing of the plurality of fasteners. Such design eliminates the need for a longitudinal translation of the annular blade. Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, the above description, disclosure, and figures should not be construed as limiting, but merely as exemplary of various embodiments.