Abstract:
An assembly for releasably attaching a buttress material onto a tissue clamping member of a surgical stapling device is disclosed. The assembly has a substantially rigid frame for connecting to a top surface of a tissue clamping member of a surgical stapling device when the assembly is disposed thereon. A buttress material is attached to first and second sides of the frame for abutting against a bottom surface of a tissue clamping member of a surgical stapling device when the assembly is disposed thereon.

Description:
FIELD OF THE INVENTION 
     The present invention relates, in general, to surgical fastening devices for applying a plurality of surgical fasteners into tissue and, more particularly, to a novel method of attaching a buttress material onto the surgical fastening device for the purpose of creating a reinforced surgical fastener line within tissue. 
     BACKGROUND OF THE INVENTION 
     Many surgical procedures involve the resection of tissue. One such procedure is lung volume reduction, which resects a portion of lung to treat emphysema. One problem encountered during the resection of body tissue, especially in conjunction with the use of staples, is the issue of hemostasis. Certain types of body tissue are more prone to the hemostasis issue such as the thin friable tissue found in the lung, and disease conditions can exacerbate the problems. Mechanical devices such as surgical staplers and linear cutters, both open and endoscopic, are utilized as a means of resecting diseased lung tissue. Staples provide hemostasis in vascular structures, and when applied to lung tissue, provide a good degree of pneumostasis as well. Surgical stapling instruments have a plurality of staples held in multiple staggered rows in a replaceable cartridge and a pair of opposed jaws of which at least one is moveable. The surgical stapling instruments compress the lung tissue between the cartridge and the jaw, and the staples are fired into the compressed tissue in close proximity to the diseased portion of the lung that is to be excised. A cutting blade is passed longitudinally between the innermost rows of formed staples, transecting the tissue. The surgical stapling device is removed from the surgical site, reloaded with another unfired stapling cartridge, and the procedure is repeated until the desired section of the lung is resected and removed. An example of an open linear cutter is given in U.S. Pat. No. 5,415,334 assigned to Ethicon Endo-Surgery, Cincinnati, Ohio on May 16, 1995, which is hereby incorporated herein by reference. An example of an endoscopic linear cutter is given in U.S. Pat. No. 5,597,107 assigned to Ethicon Endo-Surgery Cincinnati, Ohio on Jan. 28, 1997, which is hereby incorporated herein by reference. 
     One known problem with using surgical staplers used in this fashion has been the formation of air leaks in the stapled lung tissue. The leaks can occur in the cut line, and/or in the staple holes themselves. Frequently, the diseased lung tissue is thin and friable and can tear at the staples as the lungs re-inflate. These air leaks can be persistent and can extend the hospital stay for a patient by weeks. As a means to alleviate these leakage problems, surgeons reinforce the staple line by applying a buttress or pledget material to the desired stapling site and stapling through the buttress material. The buttress material provides reinforcement to the friable tissue. The tissue is compressed against the staple holes resulting in increased pneumostasis. This reduces the chances of tissue tearing at the staple line, and reduces staple pullout in friable tissue. 
     These reinforcement materials are typically releasably mounted onto the jaw members of a surgical stapling device such that upon firing, the reinforcement material is stapled to the lung tissue. Optimally the lung tissue is “sandwiched” between two layers of this reinforcement material. Alternately, buttress materials can be used in a number of other surgical procedures such as but not limited to; an ovarian hysterectomy, a gastric bypass, an anastomosis of intestinal tissue, or any other procedure that can require the reinforcement of a staple line or increased hemostasis in tissue. 
     Releasably attaching the buttress material to the jaw members of the surgical stapling device presents a special challenge. The buttress material must be fastened securely to the jaws of the surgical stapling device so that it won&#39;t fall off during normal operation, yet must be easily released from the surgical stapling device after the staples are fired. A variety of adhesive and mechanical attachment means are known. Both adhesive and mechanical attachment means are discussed below, and both have their deficiencies. 
     One example of a device which attaches a buttress material to a linear cutter with an adhesive is described in U.S. Pat. No. 5,441,193 and by Gravener et al. This device attaches buttress materials to a surgical instrument with a biocompatible cyanoacrylate adhesive. The adhesive bonding is applied along the edge portions of the buttress material and dashed lines of perforations are placed within the buttress material (adjacent to the glue line) so that the unglued central portion of buttress material can be torn from the glued edge portions. However, the portions of the buttress material having the adhesive applied thereto are not releasable from the device. As a consequence, removing the buttress from the instrument (after firing) can be especially difficult, as all of the material between the perforations must be torn simultaneously to release the surgical stapling device from tissue. 
     What is needed was an adhesive that would releasably attach the buttress material to the surgical device in a manner that makes it easier for the surgeon to remove the surgical device from the surgical site after firing. U.S. Pat. No. 5,752,965 by Francis et al. teaches the attaching the buttress material or strips to a surgical stapling device with a releasable adhesive that must be applied just prior to use. An alignment fixture is used to align the pair of buttress strips, adhesive is applied to the exposed surface of each buttress strip, and the jaws of the surgical stapling device are then closed upon the adhesive and buttress strips. When the jaws are opened, the buttress material is attached to the jaw and the cartridge of the surgical stapling device with the tacky liquid adhesive. The tacky liquid adhesive is taught as being composed of hydroxypropylmethyl cellulose, polypropylene glycol, and water. While attaching a buttress material in this manner may offer a releasable adhesive, the adhesive effects of the tacky liquid adhesive are temporary. In addition, the attachment process is time consuming, and the attachment step must be repeated for each firing. Lastly, once the tacky adhesive is exposed to air, volatile elements of the adhesive begin to evaporate. This limits the application of this tacky adhesive to just prior to or during surgery. 
     What is needed is a releasable adhesive that that won&#39;t dry out or degrade over time. Such an adhesive would enable the buttress material to be attached to the surgical stapling device at the manufacturing plant, and would result in both time and cost savings. European patent application EP 1064883A1 by Leslie Hamilton et al. teaches a releasable adhesive of nontoxic bioabsorbable aliphatic ester polymers that are semi-crystalline solids or tacky liquids (of honey-like consistency). The adhesive is characterized by being flowable at body temperatures (37° C.) and preferably flowable at room temperatures (25° C.). However, the adhesive may become much more fluid at the elevated temperatures (up to 50° C.) frequently encountered in trucks, shipping containers, railroad cars, and warehouses. Under the elevated temperature conditions, the adhesive can migrate to other parts of the instrument or instrument packaging and the migration can reduce the strength of the adhesive bond. 
     As seen from the above discussion, attaching a buttress material to a surgical stapler with an adhesive can present many problems. Mechanical attachment of buttress material to a surgical stapling device is also well known in the art and avoids the issues found with adhesives. Many methods of mechanical attachment exist, and a common one is the placement of a sleeve over the clamping members of the surgical stapling device. The sleeves can be formed from flexible fabric such as buttress material, or can contain a releasable strip of buttress material attached to a different fabric. Many of these sleeves are described in U.S. Pat. No. 5,503,638 by Cooper et al, in U.S. Pat. No. 5,702,409 by Rayburn et al., in U.S. Pat. No. 5,810,855 by Rayburn et al., and in U.S. Pat. No. 5,964,774 by McKean et al. 
     While sleeves can effectively be used to attach the buttress material to the end effector of the surgical stapling device, sleeves can cause other complications during surgery. For example, if the sleeve is formed from a solid sleeve of buttress material, firing the surgical stapling device staples the buttress and tissue and severs the buttress sleeve and tissue between the staple lines. This action leaves the portions of tissue (on either side of the cut line) attached together by a sheet of buttress material. This requires the surgeon to go in and sever the cut sleeve of buttress to separate the severed tissue, and remove any unwanted portion of the buttress material. 
     What is needed is a means of releasably attaching a buttress strip onto a surgical stapling device, that remains effective over a long period of time, remains operational at all temperatures that are likely to be encountered by the product, and is easily released from the surgical stapling device. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, an assembly for releasably attaching a buttress material onto a tissue clamping member of a surgical stapling device is disclosed. The assembly has a substantially rigid frame for connecting to a top surface of a tissue clamping member of a surgical stapling device when the assembly is disposed thereon. A buttress material is attached to first and second sides of the frame for abutting against a bottom surface of a tissue clamping member of a surgical stapling device when the assembly is disposed thereon. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is an isometric view of a surgical stapling device showing an end effector having buttress strips releasably attached to a first clamping surface of an anvil and releasably attached to a second clamping surface of a staple cartridge by a hot melt adhesive of the present invention; 
     FIG. 2 is an enlarged isometric view of the end effector of the surgical stapling device of FIG. 1 with the anvil sectioned and rotated for clarity, the view showing the step of applying the molten hot melt adhesive of the present invention onto the first and second clamping surfaces of the end effector with an applicator; 
     FIG. 3 is an enlarged isometric view of the end effector of the surgical stapling device with the anvil sectioned and rotated for clarity, the view showing the step of attaching a strip of buttress material onto each of the tissue clamping surfaces by placing the buttress material into contact with molten hot melt adhesive of the present invention placed thereon; 
     FIG. 4 is an isometric exploded view of the step of cooling the hot melt adhesive of the present invention past a set point, the releasable adhesive becoming a solid and adhering each of the portions of buttress material to each of the respective tissue clamping surfaces; 
     FIG. 5 is an isometric view of a circular stapling instrument showing buttress rings placed thereon prior to the step of applying the molten adhesive of the present invention onto an anvil and staple cartridge of the circular stapling instrument for the attachment of the buttress rings thereto; 
     FIG. 6 is an isometric view of a surgical stapling device showing an end effector having buttress strips releasably attached to a first clamping surface of an anvil by an anvil carrier, the buttress strip being removable by distal motion relative to the surgical stapling device; 
     FIG. 7 is an isometric exploded view of the elements of the anvil carrier showing the path of a perforated buttress strip as it is releasably assembled with a carrier shell; 
     FIG. 8 is an isometric view of the assembled elements of the anvil carrier of FIG. 7; 
     FIG. 9 is a distal end view of an alternate assembly of the elements of the anvil carrier; 
     FIG. 10 is an isometric exploded view of an alternate embodiment of a removable carrier shell and the perforated buttress strip; and 
     FIG. 11 is an isometric view of a circular stapling instrument with an anvil in the open position and an attachment ring attached to the anvil, wherein a perforated buttress ring is being removably and rotatably attached onto the attachment ring. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the figures in which like numerals indicate the same element throughout the views, FIGS. 6 shows a surgical stapling device  20  made in accordance with the present invention. Device  20  has an anvil carrier  90  of the present invention releasably attaching a perforated buttress strip  101  to the end effector  35 . The surgical stapling device  20  shown is an endocutter and is well known in the art for clamping, stapling, and cutting body tissue. Alternately, the surgical stapling device  20  can be one of a number of other fastening devices such as a circular stapler, a stapler, a clip applier, or any one of a number of other fastening or stapling devices capable of single or multiple firings. The staples or fasteners can be contained within a staple cartridge formed integrally with the surgical stapling device, or within a removable staple cartridge that can be fired and replaced allowing multiple firings from the same surgical fastening device. The assembly of the present invention is illustrated in FIGS. 6-11. 
     Surgical stapling device  20  has a handle  25  for the operator to grasp, an elongated shaft  30  extending distally from the handle  25 , and end effector  35  extending distally from the shaft  30 . End effector  35  has a first and a second tissue clamping member, at least one of which is movable between an open position for receiving tissue therebetween, and a closed position for stapling tissue therebetween. The first tissue clamping member has a fixed channel  31  extending from the shaft  30  and a removable staple cartridge  45  mounted therein. The second tissue clamping member is a moveable anvil  40  which is opposite to the first tissue clamping member. Staple cartridge  45  is shown placed within the fixed channel  31  and contains a plurality of staples  49  housed within. Moveable anvil  40  is operably attached to a closure trigger  26  extending from the handle  25  and moves in response to movement of the closure trigger  26 . Moving the closure trigger  26  from the open position shown in FIG. 6 towards a grip  27  of the handle  25  moves the anvil  40  from the open position of FIG. 6 to a closed position adjacent to the removable staple cartridge  45  (not shown). Movement of a firing trigger  28  towards the closure trigger  26  (when closure trigger  26  and anvil  40  are in the closed position) expels the plurality of staples  49  contained within the removable staple cartridge  45 . The staples  49  are driven from the removable staple cartridge  45 , through the buttress strips  60  and  61 , and are formed into tight “B” shapes (not shown) against the anvil  40 . An example of the surgical stapling device  20  is the TSB35 Endopath™ ETS Endoscopic Linear Cutter by Ethicon-Endo Surgery, 4545 Creek Road, Cincinnati Ohio. The surgical stapling device  20  and removable staple cartridge  45  are generally described in a commonly assigned U.S. Pat. No. 5,597,107, which is incorporated herein by reference. 
     As shown in FIG. 6, the first buttress strip  60  is releasably attached to a first tissue clamping surface  46  of the removable staple cartridge  45 . The buttress strip  60  can be formed from a wide variety of buttress materials including VICRYL®, produced by Ethicon, Inc., Somerville N.J., “DEXON®, produced by Sherwood-Davis and Geck, St. Louis, Mo., and TEFLON®, produced by E. I. DuPont de Nemours &amp; Co., Wilmington, Del. Additionally, other materials include animal material such as tanned bovine pericardium, biocompatable elastomers such as ε-caprolactone glycolide produced by Ethicon Inc., Gargrave, England, or any one of a number of suitable buttress materials. Suitable ε-caprolactone glycolide materials or foams are of special interest and are described in U.S. Pat. No. 5,468,253 hereby incorporated by reference. It is an object of the present invention to releasably attach the buttress strips  60  and  61  to at least a portion the surgical stapling device  20  for long periods of time, up to two or more years. 
     Attachment of Buttress Strips with A Hot Melt Adhesive 
     FIGS. 2-4 shows the steps of releasably attaching buttress strips  60  and  61  to the first and second tissue clamping surfaces  46 , 41  of the end effector  35  respectively, with a solid adhesive  65  of the present invention. Solid adhesive  65  is a solid at room temperatures (25° C.), a solid at body temperatures (37°), and meltable at elevated temperatures. Adhesives of this type are called hot melt adhesives, and are applied as a molten adhesive  66  during the gluing process. When the molten adhesive  66  cools, it reverts back into the solid adhesive  65 , forming an adhesive bond. In FIGS. 2-4, the end effector  35  of the surgical stapling device  20  is shown enlarged, and the anvil  40  is shown sectioned and rotated for clarity. Alternately, the hot melt adhesive  65  can be melted by a solvent and used to adhere buttress strips  60 , 61  to the surgical stapling device  20 . When the solvent evaporates from the molten adhesive  66 , it reverts back to the solid hot melt adhesive  65  and attaches the buttress strips  60 , 61  to the surgical stapling device  20 . 
     FIG. 2 shows the first step of applying the molten adhesive  66  to the first and second clamping surfaces  46 , 41  with an applicator  70 . The applicator  70  has a handle  72 , a distal nozzle  71  for the disbursement of molten adhesive  66 , a resistive heating device  75  (not shown) contained within the handle  72  to melt the a distal end of the solid adhesive  65 , and an electrical cord  74 . Attachment of the electrical cord  74  to a power supply  80  engages the resistive heating device  75 . Handle  72  has cooling slots  77  adjacent to the resistive heating device  75  to prevent overheating. These types of glue or adhesive applicators  70  are well known in the art as hot melt glue guns and are readily available for commercial or home use. An excellent example of a hot melt glue gun or adhesive applicator  70  is the SHURE BONDER® Pro 9000 glue gun made by FPL Corporation, Wauconda, Ill., 60084. 
     In FIG. 2, a rod of solid adhesive  65  is shown inserted into an opening at the proximal end of the handle  72 . As the rod of solid adhesive  65  is inserted, it operably engages a feeding mechanism (not shown) that is operably coupled to the applicator trigger  73 . Actuation of the applicator trigger  73  moves the rod of solid adhesive  65  distally within the handle until it contacts the hot resistive heating device  75  and melts the distal portion of the rod of solid adhesive  65 . Applying additional pressure on the applicator trigger  73  forces the molten adhesive  66  from an orifice  76  of the nozzle  71  and moves the rod of solid adhesive  65  distally into the applicator  70 . Whereas the hot melt glue gun or applicator  70  is the preferred method of applying the solid adhesive  65 , alternate adhesive appliers are available. These alternate adhesive appliers include but are not limited to a pressurized molten glue dispenser that applies a molten ribbon of adhesive, a sprayer that applies a spray of molten droplets, and a hot roller that applies a film of molten adhesive. 
     In FIG. 2, the applicator  70  is shown applying several lines of molten adhesive  66  onto the first and second tissue clamping surfaces  46 ,  41  of the anvil  40  and cartridge  45 . The molten adhesive is applied to these surfaces prior to the step of applying the buttress strips  60  and  61 . The molten adhesive  66  is shown being applied onto the second tissue clamping surface  41  between the staple pockets  42  embossed therein. The two lines of molten adhesive  66  are kept short on the second tissue clamping surface  41  and provide enough retention force to attach the first buttress strip  60  onto the second tissue clamping surface  41 , yet enable the first buttress strip  60  to be easily removed. 
     Two longer rows of molten adhesive  66  are shown placed upon the first clamping surface  46  of the removable staple cartridge  45 , between longitudinal rows of staple slots  47 . Each staple slot  47  has a piston-like staple driver  48  (not shown) moveable from a first recessed position deep within the removable staple cartridge  45  to a second position extending from the first tissue clamping surface  46 . In FIGS. 2 and 3, the staple drivers  48  are in the first recessed position deep within the staple slots  47  of the removable staple cartridge  45 . A “U” shaped staple  49  (not shown) is placed within each staple slot  47 , on top of the staple drivers  48  recessed therein. Movement of the staple drivers  48  to the second position ejects the staples  49  from the removable cartridge  45 . In these Figures, the staple drivers  48  and staples  49  are recessed within the staple slots  47  and cannot be seen. Staple cartridges  45  and movement of the staple drivers  48  and staples  49  are well known in the art and can be found in U.S. Pat. No. 5,415,334 by Williamson, IV et al., which is incorporated herein by reference. 
     As shown in FIG. 3, once the molten adhesive  66  is applied, the second step is to apply the buttress strips  60  and  61  onto their respective tissue clamping surfaces  46 , 41 . The first and second buttress strips  60  and  61  are shown moving towards the first and second tissue clamping surfaces  46 , 41  and the molten adhesive  66 . FIG. 4 shows the last step of the gluing process where the buttress strips  60  and  61  are placed into position, and pressed onto the respective clamping surfaces  46 , 41 . As the buttress strips  60 ,  61  are pressed into place, the molten adhesive  66  is compressed between the buttress strips  61  and the clamping surfaces  46 , 41 , and allowed to cool back into the solid adhesive  65 , attaching the buttress  60 , 61  to the surgical stapling device  20 . 
     Firing the surgical stapling device  20  moves the staple drivers  48  from the first position within the cartridge  45  to the second position, i.e. extended from the first tissue clamping surface  46 . This action simultaneously lifts and forms the staples  49  against the anvil  40  and lifts the first buttress strip  60  upwardly and away from the first tissue clamping surface  46  of the cartridge  45 . The upwards movement of the first buttress strip  60  breaks the adhesive bond between the first buttress strip  60  and the first tissue clamping surface  46 , releasing the first buttress strip  61  from the staple cartridge  45 . 
     Alternately, the buttress strip  61  can be adhered to the cartridge  45  by generally placing the molten adhesive  66  into the staple slots  47  and attaching the first buttress strip  60  onto the cartridge  45 . The molten adhesive can be placed into the staple slots  47  in two different ways. First, the hot melt can be injected directly into the staple slots  47  with the hot melt glue gun, adhering the buttress strip  60  to the staple slot  47  (not shown). Second, the molten adhesive  66  can enter the staple pockets  48  by placing the molten adhesive  66  onto the first tissue clamping surface  46  adjacent to the staple slot  47  (FIG.  3 ), and forcing it into the staple pockets  48  by pressing the first buttress strip  60  against the first clamping surface  46 . The act of pressing forces some of the molten adhesive  66  from the first tissue clamping surface  46  and into the adjacent staple slots  47 , adhering the buttress  61  to both the staple slots  47  and the first tissue clamping surface  46  (not shown). When solid adhesive  65  is within the staple slots  47  and the surgical stapling device  20  is fired, the staple drivers  48  and staples  49  move upwardly within the staple slots  47  and contact the solid adhesive  65  therein. The contact with the moving staple drivers  48  and staples  49  ejects the solid adhesive  65  from the slots  47  and breaks the adhesive bond between the first buttress strip  60  and the removable staple cartridge  45 . 
     Thus, the solid adhesive  65  of the present invention becomes a releasable adhesive when the firing of the surgical stapling instrument  20  is used to break the adhesive bond between the staple cartridge  45  and the first buttress strip  60 . It is important to note that using the firing of the stapling device  20  to break an adhesive bond is not dependent on the adhesive composition. That is, a wide variety of adhesives can be released in the manners described above. In addition to hot melt adhesives, other adhesives can be applied at room temperatures and can include adhesives such as elastomeric compounds, RTV silicones, natural and synthetic rubbers, anaerobic compounds, sealants, moldable compounds such as dental dam compounds, or maleable materials such as waxes. Additionally, the above adhesives or any one of a number of other adhesives such as acrylics, cyanoacrylates, epoxies and the like can be used with a bonding inhibitor. The bonding inhibitors act as a barrier to reduce the strength of the adhesive bond and can include oils, greases, waxes, mold releases, Teflon&#39;s, silicones or any other surface contaminant that inhibits the adhesive bonding strength. 
     The ejection of the staples  49  from the removable staple cartridge  45  also releases the second buttress strip  61  from the second tissue clamping surface  41  and forms the “U” shaped staples  49  into “B” shapes. The “U” shaped staples  49  are formed into “B” shapes by driving them through the second buttress strip  62  attached to the second tissue clamping surface  41  and against the staple pockets  42  within the anvil  40 . As the wire of the staple  49  is driven into the staple pocket  42 , the ends of the staple wire curl around into the “B” shape, and dislodge the solid adhesive  65  from the staple pockets  42  and the second tissue clamping surface  41 . This action detaches the second buttress strip  61  from the anvil  40  (not shown). 
     FIG. 5 shows molten adhesive  66  being used to attach buttress materials to a circular stapler  85 . Buttress rings  86  are shown exploded away from a first and a second circular compression surfaces  87 , 88  just prior to the step of gluing the buttress rings  86  onto the circular compression surfaces  88 , 87  with molten adhesive  66 . In FIG. 5, the molten adhesive  66  is applied onto the first compression surface  87  and is hidden. 
     The Hot Melt Adhesive Composition 
     The solid adhesive  65  can be any one of a variety of hot melt adhesives that are commercially available. It is preferable that the hot melt adhesive be biocompatible with body tissue and can be natural or synthetic. Natural biological polymers, and in particular a number of biological proteins can be used as hot melt adhesives. These proteins can include collagen, gelatin, fibrin, fibronectin, fibrinogen, elastin, serum albumin, hemoglobin, ovalbumin and the like or any combination thereof. Additionally, polysaccharides such as hyaluronic acid, chondroitin sulfate, hydroxyethyl starch, hydroxyethyl cellulose, hydroxypropyl-cellulose, carboxyetyl-cellulose, chitan/chitosan, agarose and alginate may be used alone or in combination with other materials. 
     Synthetic materials can include poly (lactic acid), poly (glycolic acid) poly (hydroxybutyrate), poly (phosphazine), polyester, polyethylene glycol, polyethylene oxide, polyacrylamide, polyhydroxyethylmethylacrylate, poly-vinypyrrolidon, polyvinyl alcohol, polyacrylic acid, polyacetate, polycaprolactone, polypropelene, nylon and the like. Also, suitable biocompatible, bioabsorbable polymers can also include but are not limited to polymers selected from the group consisting of aliphatic polyesters, poly (amino acids), copoly (ether-esters), polyalkylenes oxalates, polyamides, tyrosine derived polycarbonates, poly (iminocarbonates), polyorthoesters, polyoxaesters, polyarnidoesters, polyoxaesters containing amine groups, poly (anhydrides), polyphosphazenes, biomolecules (i.e., biopolymers such as collagen, elastin, bioabsorbable starches, etc.) and blends thereof 
     Of special interest for the solid adhesive  65  is a copolymer that is a solid at temperatures generally below 40° C. The preferred copolymer is a copolymer of ε-caprolactone or trimethylene carbonate and glycolide. Most preferably, the copolymer is a copolymer of ε-caprolactone and glycolide. The amount of ε-caprolactone can be between 30 and 45 mole percent with the balance being glycolide. Ideally, the copolymer can be composed of 36:64 (mol/mol) [poly (ε-caprolactone-co-glycolide)]. The copolymer is an elastomeric containing less than one percent of unreacted monomer as determined by proton NMR spectography. The inherent viscosity is determined in a 0.1 g/dL solution of hexaflouroisopropanol (HFIP) at 25° C., and can range from about 0.8 g/dL to about 3.2 g/dL, preferably from about 0.6 g/dL to about 2.4 g/dL, and most preferably at about 1.6 g/dL. In an especially preferred embodiment, both the preferred solid adhesive and the preferred buttress material can be formed from the same bioabsorbable material, ε-caprolactone glycolide. 
     The solid adhesive  65  can be characterized as being a solid at temperatures up to 40° C. and melts without degradation at elevated temperatures between 40.1° C. to 600° C. More preferred are solid adhesives  65  that melt without degradation at elevated temperatures between 120° C. to 240° C. and most preferably at 180° C. The copolymer described above can be prepared in accordance with the descriptions provided in U.S. Pat. Nos. 5,468,253, 5,133,739, and 4,605,730, each of which is incorporated by reference. 
     Alternate Device and Method for Attaching Buttress Strips to an Anvil 
     FIGS. 6-11 illustrate another device and method for attaching a buttress strip onto an anvil  40  of the surgical stapling device  20  of FIG.  1 . FIG. 6 shows the surgical stapling device  20  with an anvil carrier  90  secured to the anvil  40 , and a buttress strip removably attached to the anvil carrier  90 . Anvil carrier  90  slides onto the anvil  40  and locks onto the anvil  40  when fully mounted. The lock can be easily disengaged for removal or replacement of the anvil carrier  90 . 
     As best shown in FIGS. 7-9, the anvil carrier  90  is assembled from a frame or carrier shell  91  and a perforated buttress strip  100 . Carrier shell  91  is hollow, is conformed to slip over the anvil  40 , has an inverted “U” shaped carrier body  92 , and has a nose  95  extending distally therefrom. Nose  95  can be blunt or atraumatic to prevent tissue damage during placement of the surgical stapling device  20  at the surgical site. A spring member  96  connects nose  95  to a distal end of the carrier body  92 . A lock or retention feature  97  is located on an inner surface (not shown) of the nose  95  to releasably engage the anvil carrier  90  with the anvil  40  of the surgical stapling device  20 . The retention feature  97  can be a convex dimple or rib that engages with a concave mating feature (not shown) on the anvil  40  of the surgical stapling device  20 . Lifting the nose  95  away from the anvil  40  (when the retention feature  97  is engaged with the anvil  40 ) deflects the spring member  96 , lifts the retention feature  97  from the concave mating feature on the anvil  40 , and unlocks the carrier shell from the anvil  40 . A plurality of attachment features, such as “L” shaped hooks  93 , extend downwardly on each side of the carrier body  92 , with arms  94  extending horizontally in the distal direction from a vertical portion or first member  93   a  of the “L” shaped hooks  93 . Whereas hooks  93  are the preferred embodiment, spikes, arms, tabs, bosses or any one of a number of releasable means can be added to the carrier shell  91 . Carrier shell  91  can be made from a rigid or semi-rigid material such as an engineering plastic, examples of which can include liquid crystal polymers, polycarbonates, polystyrenes, or any one of a number of suitable medical grades of engineering thermoform plastics or thermoset plastics. Additionally, the carrier shell  91  can also be formed from any metallic material such as aluminum, steel, stainless steel, copper, or combinations and alloys thereof. 
     Perforated buttress strip  100  is a rectangular sheet formed from any of the buttress materials described above, and has rows of spaced-apart openings  101  extending therethrough. Perforated buttress strip  100  is attached onto the carrier shell  91  by threading each horizontal arm  94  fully into each respective opening  101  within the perforated buttress strip  100  until the openings  101  are brought into contact with the first member  93   a  or vertical portion of the “L” shaped hooks  93 . Moving the perforated buttress strip  100  distally relative to the carrier shell  91 , moves the openings  101  off of the arms  94  and releases the perforated buttress strip  100  from the carrier shell  91 . Thus, the perforated buttress strip  100  is detachable from the carrier shell  91  by linear motion in one direction. Arrows are provided in FIG. 7 to show the path of the openings  101  as the perforated buttress strip  100  is threaded onto the arms  94 . 
     FIG. 8 is an isometric view showing the preferred assembly of the perforated buttress strip  100  with the carrier shell  91 . In this assembly, each of the arms  94  of the hooks  93  are shown placed into their respective openings  100  within perforated buttress strip  100 . When the arms  94  are assembled with the openings  101 , a slight dimpling occurs at the edges of the perforated buttress  100  from the placement of the arms  94  into the openings  101 . When the preferred assembly of the anvil carrier  90  is installed onto the anvil  40 , the perforated buttress strip  100  is tented away from the carrier shell  91  by the second clamping surface  41  of the anvil  40 , flattening the perforated buttress strip  100 . 
     FIG. 9 is a cross sectional view of an alternate assembly of the perforated buttress strip  100  with the carrier shell  91 . In this Figure, the edges of the perforated buttress strip  100  are folded upwardly along each row of openings  101  into a general “U” shape. The vertical sides of the “U” shaped perforated buttress  101  are then placed inside of the hooks  93 , and each of the arms  94  are threaded into their respective openings  101 . This attachment method produces a generally flat horizontal section on the attached perforated buttress strip  100 . 
     During surgery, the anvil carrier  90  is used in the following manner. The anvil carrier  90  (containing a perforated buttress strip  100 ) is slid onto the open anvil  40  of the surgical stapling device  20 . Next, the anvil  40  is closed and the end effector  35  of the surgical stapling device  20  is inserted into the patient. The anvil  40  is opened and the end effector is placed onto tissue at a selected surgical site. Anvil  40  is closed to clamp tissue between a second clamping surface  41  on the anvil  40  and a first clamping surface  46  on the removable staple cartridge  45 . The surgical stapling device  20  is fired, stapling the perforated buttress strip  100  onto tissue and severing the tissue and buttress between the staple lines. The anvil  40  is opened, and the surgical stapling device  20  is withdrawn proximally away from the surgical site. As the surgical stapling device  20  is withdrawn, the stapled perforated buttress strip  100  remains attached to tissue and the arms  94  of the carrier shell  91  slip out of the openings  101  within the perforated buttress strip  100 , releasing the perforated buttress strip  100  from the surgical stapling device  20 . To reload the surgical stapling device  20  with a fresh anvil carrier  90 , the surgeon must remove the surgical stapling device  20  from the patient. Next, the surgeon removes the spent carrier shell  91  from the anvil  40  by lifting the nose  95  to unlock the retention feature  97  from the anvil  40  and slides the carrier shell  91  off of the anvil  40 . A fresh anvil carrier  90  is slid onto the anvil  40  to finish the reloading process. 
     FIG. 10 shows an alternate embodiment of a removable carrier shell  191  that can be simultaneously detached from both the anvil  40  and perforated buttress strip  100 , releasing the perforated buttress strip  100  from the surgical stapling device  20  in the process. Removable carrier shell  191  and has elongated carrier body  192 , hooks  193  with arms  194  and first member  193   a  extending therefrom and a nose  195 . A tang  198  extends from the proximal end of the carrier shell  191 , and has a long suture or cable  199  fixedly attached to the tang  116 . Perforated buttress strip  100  can be assembled with the removable carrier shell  115  in either manner described previously and shown in FIGS. 8 and 9. 
     During surgery, removable carrier shell  191  having perforated buttress strip  100  attached thereto are slid onto the anvil  40  of the end effector  35 . Cable  199  is then extended proximally from the removable carrier shell  191  along the shaft  30 , and terminated with a free end adjacent to the handle  25  of the surgical stapling instrument  20 . Placement of the end effector  35  into a patient (through a trocar) leaves the free end of the cable  199  outside of the patient&#39;s body. After clamping the end effector  35  on tissue and firing the surgical stapling device  20 , the perforated buttress strip  100  is released from the surgical stapling device  20  by pulling on the cable  199 . Pulling on the cable  199  simultaneously moves the removable carrier shell  191  distally and detaches it from the anvil  40 . As the removable carrier shell  191  moves distally, the arms  194  are withdrawn from the openings  101  within the perforated buttress strip  101  releasing the perforated buttress strip  100  from the removable carrier shell  191  and the anvil  40 . Opening the anvil  40  releases the perforated buttress strip  100  and attached tissue from the end effector  35 . The cable  199  is then used to withdraw the spent removable carrier shell  115  from the patient through the trocar. 
     FIG. 11 shows yet another embodiment of removably attaching perforated buttress to a stapling device, a circular stapler  85 . In this embodiment, the buttress is released from the circular stapling device by a rotary motion, rather than the linear motion described previously. As shown, the circular stapler  85  has an open circular anvil  89  and a longitudinal axis. An attachment ring  105  is attached to or formed from the circular anvil  89 . Tab hooks  106  extend distally from the attachment ring  105  towards the body of the instrument and have tab arms  106   a.  Tab arms  106   a  extend from the tab hooks  106  in the same counter clockwise direction around the periphery of the circular anvil  89 . The tab hooks  106  are spaced radially outwardly so that the so that circular anvil  85  can fully close without crushing the tab hooks  106 . 
     A perforated buttress ring  107  is provided to attach to the tab hooks  106  extending from the circular anvil  89 . A plurality of tabs  108  are spaced about the periphery of the perforated buttress ring  107 , with a tab opening  109  extending through each tab  108 . As shown, there are four tabs  108  equally spaced about the periphery of the perforated buttress ring  107  and a like number of tab hooks  106 . To removably attach the perforated buttress ring  107  to the tab hooks  106  of attachment ring  105 , the tab openings  109  are placed onto the tab arms  106   a  and the perforated buttress ring  107  is rotated clockwise. Likewise, counterclockwise rotation removes an attached perforated buttress ring  107 . Alternately, the tab arms  106   a  can extend in a clockwise direction, in which case the perforated buttress ring  107  is rotated counterclockwise to install and clockwise to remove. After stapling the perforated buttress ring  107  onto tissue, the circular anvil  89  is opened and the circular stapler  85  is rotated clockwise to withdraw the arms  94  from the tab openings and releasing the perforated buttress ring  107  from the circular stapler  85 . Since the circular stapler  85  is a single shot instrument, the attachment ring  105  can be permanently or removably attached to the circular anvil  89 . Alternately, a perforated buttress ring  107  can be attached over the first circular compression surface  88  by attaching a second attachment ring  105  adjacent to the first circular compression surface  88  with the tab hooks  106  extending distally (not shown). If attachment rings  105  are attached adjacent to both the first and second circular compression surfaces  88 , 87 , care must be taken to orient both sets of attachment ring hooks  94  to prevent contact during closure, and the arms  94  on both attachment rings  105  in the same direction (not shown). With the arms  94  oriented in the same direction, rotating the circular stapler  85  detaches both perforated buttress rings  107  simultaneously. 
     Although particular embodiments of the present invention have been shown and described, modification may be made to the device and/or method without departing from the spirit and scope of the present invention. The terms used in describing the invention are used in their descriptive sense and not as terms of limitations.