Patent Description:
Surgical stapling apparatus are employed by surgeons to sequentially or simultaneously apply one or more rows of fasteners, e.g., staples or two-part fasteners, to body tissue for the purpose of joining segments of body tissue together. Such apparatus generally include a pair of jaws or finger-like structures between which the body tissue to be joined is placed. When the surgical stapling apparatus is actuated, or "fired", longitudinally moving firing bars contact staple drive members in one of the jaws. The staple drive members push the surgical staples through the body tissue and into an anvil in the opposite jaw which forms the staples. If body tissue is to be removed or separated, a knife blade can be provided in the jaws of the apparatus to cut the body tissue between the lines of staples.

Surgical supports, e.g., meshes or buttress materials, may be used in combination with surgical stapling apparatus to bridge, repair, and/or reinforce tissue defects within a patient. A clinician may manually attach buttress material(s) to the surgical stapling apparatus in the operating room during a surgical procedure, or utilize a surgical stapling apparatus including the buttress material(s) pre-installed thereon, e.g., by an expensive automated attachment process. The buttress material reinforces the staple or suture line as well as covers the juncture of the tissues to reduce leakage prior to healing. The Applicant's publication <CIT> (prior art according to Art. <NUM>(<NUM>) EPC) discloses one type of anvil buttress loading assembly including an anvil assembly, an anvil buttress loading tool, and an anvil buttress. The anvil buttress is retainable on each of the anvil buttress loading tool and the anvil buttress and is transferable from the anvil buttress loading tool to the anvil assembly. The anvil assembly comprises a spring and hook assembly which can be contacted by a ramp of the anvil buttress loading tool to raise second fingers of the spring and hook assembly off of the tissue facing surface of the anvil plate and lift first fingers out of notches defined in the tissue facing surface. Once the ramp clears the second fingers, the arms snap back down and the first fingers extend through a proximal window in the anvil buttress and re-enter the notches thereby capturing the proximal end portion of the anvil buttress to the anvil assembly.

The present disclosure relates to anvil side buttress material attachment onto a jaw assembly of a surgical stapling apparatus. Anvil buttress attachment systems, assemblies, and methods of the present disclosure are designed to provide robust, releasable mechanical attachment of an anvil buttress to an anvil assembly, and to make anvil side buttress material attachment in the operating room a simple, straightforward, and cost-effective procedure.

The present invention provides an anvil buttress loading system as defined in claim <NUM>. The anvil buttress loading system includes an anvil assembly, an anvil buttress loading tool, and an anvil buttress. The anvil assembly includes an anvil plate and an anvil tip. The anvil plate has a tissue facing surface with a proximal end portion of the tissue facing surface including a pin assembly. The anvil buttress loading tool includes a base having a support surface, a loading ramp extending proximally of the base, and a flange extending distally from the base. The anvil buttress includes a body, a proximal tab extending proximally from the body, and a distal tab extending distally from the body. The anvil buttress is releasably retained (e.g., pre-loaded) on the anvil buttress loading tool with the body positioned on the support surface, the proximal tab positioned over the loading ramp, and the distal tab positioned within the flange. The anvil buttress is transferrable from the anvil buttress loading tool to the anvil assembly such that the anvil buttress is releasably secured to the anvil assembly with the body positioned on the tissue facing surface, the proximal tab engaged with the pin assembly, and the distal tab engaged with the anvil tip.

The pin assembly of the anvil assembly may include a pair of retaining pins disposed on opposed sides of a central longitudinal slot defined through the tissue facing surface of the anvil plate. Each retaining pin may include a body positioned against the tissue facing surface and movable relative thereto. The bodies of the pair of retaining pins are configured to hold the proximal tab of the anvil buttress against the tissue facing surface. The tissue facing surface of the anvil assembly may include a groove defined therein. The bodies of the pair of retaining pins may be biased to extend into the groove. Each retaining pin may include an arm extending laterally from the body and secured to the anvil assembly. Each of the bodies of the pair of retaining pins may be disposed at an angle relative to the tissue facing surface of the anvil assembly.

The loading ramp of the anvil buttress loading tool may include a proximal end and a sloped surface sloping upwardly and distally from the proximal end to a distal end of the loading ramp. The loading ramp may be configured to move the bodies of the pair of retaining pins off of the tissue facing surface of the anvil assembly during transfer of the anvil buttress to the anvil assembly. The loading ramp may be coupled to the base by a post, and a pair of apertures may be defined on opposed sides of the post between the base and the loading ramp. The bodies of the pair of retaining pins may be configured to follow the sloped surface of the loading ramp and pass into the pair of apertures during transfer of the anvil buttress to the anvil assembly.

The flange of the anvil buttress loading tool may be disposed at an angle relative to the base. A distal opening may be defined through the flange of the anvil buttress loading tool and a distal window may be defined through the distal tab of the anvil buttress. The distal window may be aligned with the distal opening such that during transfer of the anvil buttress to the anvil assembly, the anvil tip of the anvil assembly engages the distal tab through the distal window.

The present disclosure provides an anvil buttress loading assembly including an anvil buttress loading tool and an anvil buttress. The anvil buttress loading tool includes a base having a support surface, a loading ramp extending proximally of the base, and a flange extending distally from the base. The anvil buttress includes a body, a proximal tab extending proximally from the body, and a distal tab extending distally from the body. The body of the anvil buttress is positioned on the support surface, the proximal tab of the anvil buttress is positioned over the loading ramp, and the distal tab is positioned within the flange.

The loading ramp may include a proximal end and a sloped surface sloping upwardly and distally from the proximal end to a distal end of the loading ramp. The loading ramp may be coupled to the base by a post, and a pair of apertures may be defined on opposed sides of the post between the base and the loading ramp.

The flange may extend at an angle relative to the base. A distal opening may be defined through the flange of the anvil buttress loading tool and a distal window may be defined through the distal tab of the anvil buttress. The distal window may be aligned with the distal opening.

The tool assembly includes a staple cartridge assembly, an anvil assembly, and an anvil buttress. The anvil assembly includes an anvil plate and an anvil tip. The anvil plate has a tissue facing surface with a proximal end portion of the tissue facing surface including a pin assembly. The anvil buttress includes a body disposed over the tissue facing surface, a proximal tab releasably coupled to the anvil assembly by the pin assembly, and a distal tab releasably coupled to the anvil tip.

The pin assembly of the anvil assembly may include a pair of retaining pins disposed on opposed sides of a central longitudinal slot defined through the tissue facing surface of the anvil plate. Each retaining pin may include a body positioned against the tissue facing surface and movable relative thereto, the bodies of the pair of retaining pins holding the proximal tab of the anvil buttress against the tissue facing surface. The tissue facing surface of the anvil assembly may include a groove defined therein. The bodies of the pair of retaining pins may be biased to extend into the groove. Each retaining pin may include an arm extending laterally from the body and secured to the anvil assembly. Each of the bodies of the pair of retaining pins may be disposed at an angle relative to the tissue facing surface of the anvil assembly.

The anvil buttress may include a distal window defined through the distal tab. The distal tab may be coupled to the anvil assembly by engagement of the distal tab around the anvil tip through the distal window.

Other aspects, as well as features, objects, and advantages of the aspects described in this disclosure will be apparent from the description and drawings, and from the claims.

Embodiments of the present disclosure will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. Throughout this description, the term "proximal" refers to a portion of a structure, or component thereof, that is closer to a user, and the term "distal" refers to a portion of the structure, or component thereof, that is farther from the user.

Referring now to <FIG>, an exemplary surgical stapling apparatus or surgical stapler <NUM> is shown for use in stapling tissue in accordance with aspects of the present disclosure. The surgical stapling apparatus <NUM> will be described to the extent necessary to disclose aspects of the present disclosure.

The surgical stapling apparatus <NUM> generally includes a handle assembly <NUM>, an elongate tubular body <NUM> extending distally from the handle assembly <NUM>, and a loading unit <NUM> extending distally from the elongate tubular body <NUM>. The handle assembly <NUM> may be manually driven or may be powered (e.g., by an electric motor). For a detailed description of the structure and function of exemplary surgical stapling apparatus, including exemplar manual and powered handle assemblies, exemplar elongate tubular bodies, and exemplar loading units, reference may be made to <CIT>, <CIT>, and <CIT>.

It should be appreciated that principles of the present disclosure are equally applicable to surgical stapling apparatus having other configurations such as, for example, the types described in <CIT> and <CIT>. Accordingly, it should be understood that a variety of surgical stapling apparatus may be utilized with aspects of the present disclosure. For example, laparoscopic or open staplers, such as, for example, GIA™, Endo GIA™, TA™, and Endo TA™ staplers and/or linear and radial reloads with, for example, Tri-Staple™ technology, available through Medtronic (North Haven, CT) may be utilized with aspects of the present disclosure.

The loading unit <NUM> may also be configured for use with other surgical apparatus, such as robotic devices/instruments. For a detailed description of the structure and function of exemplary robotic systems, reference may be made to <CIT> and <CIT>.

The loading unit <NUM> includes a tool or jaw assembly <NUM> including first and second jaw members 32a, 32b. One or both of the first and second jaw members 32a, 32b is pivotable with respect to the other such that the tool assembly <NUM> is movable between an open position in which the first and second jaw members 32a, 32b are spaced apart with respect to each other, and a closed position in which the first and second jaw members 32a, 32b are substantially adjacent each other.

The loading unit <NUM> is a disposable loading unit ("DLU") that is releasably secured to the elongated tubular body <NUM> and thus, replaceable with a new loading unit <NUM>. The loading unit <NUM> may be a single use loading unit ("SULU") that is used one time and then replaced to facilitate multiples uses of the surgical stapling apparatus <NUM> on a patient. For example, during a surgical procedure, the surgical stapling apparatus <NUM> can be used to staple and cut tissue, and the entire SULU is replaced after each staple and cut operation of the surgical stapling apparatus <NUM>. The loading unit <NUM> may be a multi-use loading unit ("MULU") that is re-useable a predetermined number of times. For example, during a surgical procedure, the surgical stapling apparatus <NUM> can be used to staple and cut tissue, and a reload assembly (e.g., a staple cartridge <NUM>) of the MULU is replaced after each staple and cut operation of the surgical stapling apparatus <NUM> a pre-determined number of times before the entire MULU is replaced. Alternatively, the loading unit <NUM> may be permanently affixed to the elongated tubular body <NUM>.

The first jaw member 32a of the tool assembly <NUM> includes a staple cartridge assembly <NUM> and the second jaw member 32b of the tool assembly <NUM> includes an anvil assembly <NUM>. The staple cartridge assembly <NUM> includes a staple cartridge <NUM> that may be removably and/or replaceably attached to a cartridge carrier <NUM> of the staple cartridge assembly <NUM>. The staple cartridge <NUM> may be any staple cartridge used in surgical stapling apparatus within the purview of those skilled in the art that includes a plurality of fasteners (e.g., staples) releasably disposed therein.

As shown in <FIG>, the anvil assembly <NUM> includes an anvil plate <NUM> and an anvil cover <NUM> (<FIG>) secured over the anvil plate <NUM>. The anvil plate <NUM> has a central longitudinal slot <NUM> formed therein and a plurality of staple forming pockets or cavities <NUM> defined in an inward or tissue facing surface <NUM> thereof. An anvil tip <NUM> extends distally of the staple forming pockets <NUM>. The anvil tip <NUM> has a curved leading end 58a and a pair of notches 58b defined in opposed side edges of the anvil tip <NUM>. The pair of notches 58b are configured to releasably secure a distal portion of an anvil buttress to the anvil assembly <NUM>. A proximal portion 52a of the anvil plate <NUM>, which extends proximally of the staple forming pockets <NUM>, includes a groove <NUM> defined in and extending across the tissue facing surface <NUM> and a pin assembly <NUM> configured to releasably secure a proximal portion of an anvil buttress to the anvil assembly <NUM>.

The pin assembly <NUM> includes a pair of retaining blocks <NUM> and a pair of retaining pins <NUM> disposed on opposed sides of the central longitudinal slot <NUM> of the anvil plate <NUM>. Each retaining block <NUM> is secured to or integrally formed with an inner side surface 54a of the anvil cover <NUM>. A proximal portion 62a of the retaining block <NUM> is aligned with the groove <NUM> of the anvil plate <NUM> and a distal portion 62b of the retaining block <NUM> includes one or more pin holes <NUM> defined in a surface of the retaining block <NUM> facing the central longitudinal slot <NUM>.

Each retaining pin <NUM> is formed from a rod of material (e.g., a metal wire) that is pre-formed (e.g., bent) into an open frame including a body <NUM> having a substantially rectangular shape and a pair of arms <NUM> extending laterally from the body <NUM>. The retaining pins <NUM> are formed from a rigid material that is capable of holding its shape and undergoing elastic deformation upon application of a force thereto, as described in detail below. The pair of arms <NUM> are non-rotatably disposed (e.g., secured) within the pin holes <NUM> of the retaining blocks <NUM> and the body <NUM> extends across the tissue facing surface <NUM> of the anvil plate <NUM> between the retaining block <NUM> and the central longitudinal slot <NUM>, with a segment 66a of the body <NUM> positioned within the groove <NUM> defined in the tissue facing surface <NUM> of the anvil plate <NUM>.

As the groove <NUM> is disposed proximal to the pin holes <NUM>, the body <NUM> of the retaining pin <NUM> is disposed at an angle with respect to the tissue facing surface <NUM> of the anvil assembly <NUM>. The retaining pin <NUM> is positioned such that the body <NUM> is biased to extend into the groove <NUM>. In some aspects, the body <NUM> is held under strain within the groove <NUM>. The body <NUM> of the retaining pin <NUM> is movable out of the groove <NUM> (e.g., capable of being raised out of the groove <NUM> and off of the tissue facing surface <NUM>) upon application of a force thereto. The body <NUM> may be disposed at an acute angle with respect to the portion of the tissue facing surface <NUM> including the staple forming pockets <NUM> such that the body <NUM> is movable upon application of a force in only a proximal direction.

It should be understood that the pin assembly <NUM> may have other configurations. For example, each retaining pin may include a single arm, the arm(s) of each retaining pin may be directly coupled to the anvil assembly (e.g., the retaining blocks may be omitted), and/or the body of each retaining pin may be sized and shaped to directly abut the tissue facing surface of the anvil assembly (e.g., the groove may be omitted).

Turning now to <FIG>, an anvil buttress <NUM> (also referred to herein generally as a surgical buttress) is shown separated from an anvil buttress loading tool <NUM> (also referred to herein generally as a loading tool). The anvil buttress <NUM> includes a body <NUM> having a tissue contacting surface 73a and an anvil contacting surface 73b. The body <NUM> has a generally rectangular shape that is sized to cover the tissue facing surface <NUM> (<FIG>) of the anvil assembly <NUM>. A pair of wings <NUM> extend from opposed sides of a proximal portion 72a of the body <NUM>.

A proximal tab <NUM> extends proximally from the proximal portion 72a of the body <NUM> and has a smaller width than the body <NUM>. A proximal window <NUM> is defined in a distal portion 76b of the proximal tab <NUM>. A distal tab <NUM> extends distally from a distal portion 72b of the body <NUM>. The distal tab <NUM> is bent to extend at an angle relative to the body <NUM> and has a distal window <NUM> defined therethrough. The distal window <NUM> is sized and shaped to receive the anvil tip <NUM> (<FIG>) therethrough. The distal window <NUM> may be configured so that the distal tab <NUM> engages the notches 58b (<FIG>) in the anvil tip <NUM> to aid in retaining the distal tab <NUM> thereto. In aspects in which notches 58b are not defined in the anvil tip <NUM>, the distal window <NUM> is configured so that the distal tab <NUM> frictionally engages the anvil tip <NUM>. In some aspects, the distal tab <NUM> may be stiffened to retain the bend relative to the body <NUM> and, in other aspects, the distal tab <NUM> is bent relative to the body <NUM> by positioning the distal tab <NUM> within a flange <NUM> of the anvil buttress loading tool <NUM>. In aspects, the distal tab <NUM> extends at an acute angle relative to anvil facing surface 73b of the body <NUM> to aid in retaining the distal tab <NUM> to the anvil tip <NUM>.

The anvil buttress <NUM> is fabricated from biocompatible materials which are bioabsorbable or non-absorbable, natural or synthetic materials. It should be understood that a single or combination of natural, synthetic, bioabsorbable, and/or non-bioabsorbable materials may be used to form the anvil buttress <NUM>. In aspects, the anvil buttress <NUM> is formed from a single sheet of material that is cut to shape. In other aspects, the anvil buttress <NUM> is formed from a plurality of sheets of material, that are fabricated from the same or different materials, and/or the components (e.g., the body, the wings, the tabs, etc.) of the anvil buttress <NUM> are formed from the same or different materials that are attached to one another by, for example, welding, using adhesive, tying sutures, etc..

The anvil buttress <NUM> may be porous, non-porous, or combinations thereof. Suitable porous structures include, for example, fibrous structures (e.g., knitted structures, woven structures, and non-woven structures) and/or foams (e.g., open or closed cell foams). Suitable non-porous structures include, for example, films. The anvil buttress <NUM> may be a single porous or non-porous layer, or include a plurality of layers including any combination of porous and non-porous layers. For example, the anvil buttress may include multiple porous and non-porous layers that are stacked in an alternating manner. In another example, the anvil buttress may be formed in a "sandwich-like" manner wherein the outer layers are porous and the inner layer(s) are non-porous, or vice versa.

Porous layer(s) in a surgical buttress may enhance the ability of the surgical buttress to absorb fluid, reduce bleeding, and/or seal a wound. Also, the porous layer(s) may allow for tissue ingrowth to fix the surgical buttress in place. Non-porous layer(s) in a surgical buttress may enhance the ability of the surgical buttress to resist tears and perforations during the manufacturing, shipping, handling, and/or stapling processes. Also, non-porous layer(s) may retard or prevent tissue ingrowth from surrounding tissues thereby acting as an adhesion barrier and preventing the formation of unwanted scar tissue.

With continued reference to <FIG>, the anvil buttress loading tool <NUM> is configured to releasably retain the anvil buttress <NUM> thereon and to receive the anvil assembly <NUM> (<FIG>) therein for loading the anvil buttress <NUM> onto the anvil assembly <NUM> (e.g., transferring the anvil buttress <NUM> from the anvil buttress loading tool <NUM> to the anvil assembly <NUM>). The anvil buttress loading tool <NUM> includes a base <NUM> having a support surface <NUM> and longitudinal rails <NUM> extending from opposed sides of the base <NUM>. The support surface <NUM> is dimensioned to accommodate the body <NUM> of the anvil buttress <NUM> thereon. The longitudinal rails <NUM> help maintain alignment of the anvil buttress <NUM> on the anvil buttress loading tool <NUM> and act as guides during loading and unloading of the anvil buttress loading tool <NUM> onto and off of the anvil assembly <NUM>.

The anvil buttress loading tool <NUM> includes a loading ramp <NUM> at a proximal end 80a thereof and a flange <NUM> at a distal end 80b thereof. The flange <NUM> is bent to extend at an angle relative to the base <NUM> and defines a distal opening <NUM> therethrough. In aspects, the flange <NUM> is bent at an acute angle relative to the support surface <NUM> of the base <NUM>. The flange <NUM> is configured to receive the distal tab <NUM> of the anvil buttress <NUM> therein. The distal opening <NUM> in the flange <NUM> is dimensioned to correspond with the dimensions of the distal window <NUM> in the anvil buttress <NUM> which, in turn, is dimensioned to receive and frictionally engage the anvil tip <NUM>, as described above.

As shown in <FIG>, the loading ramp <NUM> is interconnected with the base <NUM> by a post <NUM> such that a pair of apertures or cut-outs <NUM> are defined on opposed sides of the post <NUM> between the base <NUM> and the loading ramp <NUM>. In aspects, the width of the post <NUM> corresponds with a width of the central longitudinal slot <NUM> (<FIG>) of the anvil assembly <NUM>. The loading ramp <NUM> includes a proximal end 86a which acts as a camming surface to move the retaining pins <NUM> (<FIG>) of the pin assembly <NUM> of the anvil assembly <NUM>, as described below, and a sloped surface 86c sloping upwardly and distally from the proximal end 86a to a distal end 86b of the loading ramp <NUM> for guiding the movement of the retaining pins <NUM> during loading of the anvil buttress <NUM> onto the anvil assembly <NUM>. The loading ramp <NUM> and the post <NUM> are dimensioned to accommodate the proximal tab <NUM> of the anvil buttress <NUM> thereon. In some aspects, a proximal portion 76a of the proximal tab <NUM> is positioned on the loading ramp <NUM> and the post <NUM>, and the distal portion 76b of the proximal tab <NUM> is positioned on the base <NUM>.

In a method of loading the anvil buttress loading tool <NUM> with the anvil buttress <NUM>, the body <NUM> of the anvil buttress <NUM> is placed against the support surface <NUM> of the base <NUM> with the tissue contacting surface 73a of the anvil buttress <NUM> in contact with the support surface <NUM> and the pair of wings <NUM> disposed proximal to the longitudinal rails <NUM>. With the body <NUM> of the anvil buttress <NUM> positioned on the support surface <NUM>, the proximal tab <NUM> of the anvil buttress <NUM> is positioned on the loading ramp <NUM> and the distal tab <NUM> is positioned within the flange <NUM> such that the distal window <NUM> is aligned or in registration with the distal opening <NUM> of the flange <NUM>. The loaded configuration of the anvil buttress <NUM> on the anvil buttress loading tool <NUM> is shown in <FIG>. The anvil buttress <NUM> is releasably retained on the anvil buttress loading tool <NUM> by, for example, static friction, modification of the surface characteristics (e.g., texture) of the anvil buttress loading tool for gripping of the anvil buttress, application of a light adhesive or adhesive with low aggressiveness between the anvil buttress loading tool and the anvil buttress, etc..

As shown in <FIG>, in a method of loading the anvil assembly <NUM> with the anvil buttress <NUM>, the anvil buttress loading tool <NUM>, loaded with the anvil buttress <NUM>, is positioned relative to the anvil assembly <NUM> with the anvil buttress <NUM> facing the tissue facing surface <NUM> of the anvil assembly <NUM>, as seen in <FIG>. The loading ramp <NUM> of the anvil buttress loading tool <NUM> is distal to and aligned with the pin assembly <NUM> of the anvil assembly <NUM>, as seen in <FIG> and <FIG>, and the flange <NUM> of the anvil buttress loading tool <NUM> is distal to and aligned with the anvil tip <NUM> of the anvil assembly <NUM>, as seen in <FIG>.

The anvil buttress loading tool <NUM> is placed adjacent to the anvil assembly <NUM> with the anvil buttress <NUM> in contact with the tissue facing surface <NUM> of the anvil assembly <NUM>, as seen in <FIG>. The anvil buttress loading tool <NUM> is slid proximally over the anvil assembly <NUM> and is guided by the longitudinal rails <NUM> (<FIG>) to maintain alignment of the anvil buttress loading tool <NUM> on the anvil assembly <NUM>. During this sliding movement, the proximal end 86a of the loading ramp <NUM> contacts the retaining pins <NUM> of the pin assembly <NUM>, pivoting and lifting the bodies <NUM> of the retaining pins <NUM> proximally and upwardly out of the groove <NUM> and away from the tissue facing surface <NUM> of the anvil plate <NUM> and along the sloped surface 86c of the loading ramp <NUM>.

The bodies <NUM> of the retaining pins <NUM> follow the sloped surface 86c of the loading ramp <NUM> until the loading ramp <NUM> clears the retaining pins <NUM> (e.g., the loading ramp <NUM> is proximal of the bodies <NUM>) and the bodies <NUM> snap back down into the groove <NUM> defined in the anvil plate <NUM>, as seen in <FIG>, as the retaining pins <NUM> return to their biased position. The bodies <NUM> of the retaining pins <NUM> move into the apertures <NUM> of the anvil buttress loading tool <NUM> and capture the proximal tab <NUM> of the anvil buttress <NUM> within the groove <NUM> of the anvil plate <NUM>. In this fully advanced position, the flange <NUM> of the anvil buttress loading tool <NUM> is engaged with the anvil tip <NUM> of the anvil assembly <NUM> such that the anvil tip <NUM> extends through the distal opening <NUM> of the flange <NUM> and is engaged with the distal tab <NUM> of the anvil buttress <NUM> through the distal window <NUM>. It should be understood that additionally or alternatively, the anvil assembly <NUM> may be slid distally relative to the anvil buttress loading tool <NUM>.

Once the anvil buttress loading tool <NUM> is fully advanced onto the anvil assembly <NUM>, as seen in <FIG>, the anvil buttress loading tool <NUM> is separated from the anvil assembly <NUM> by lifting the proximal end 80a of the anvil buttress loading tool <NUM> off of the anvil assembly <NUM> in the direction of arrow "A," as seen in <FIG>, so that the anvil buttress loading tool <NUM> clears the retaining pins <NUM> of the anvil assembly <NUM> through the apertures <NUM>. As the proximal end 80a of the anvil buttress loading tool <NUM> is separated from the anvil assembly <NUM>, the anvil buttress loading tool <NUM> is moved distally relative to the anvil assembly <NUM> in the direction of arrow "B," as also seen in <FIG>, so that the distal end 80b of the anvil buttress loading tool <NUM> clears the anvil tip <NUM> of the anvil assembly <NUM> through the distal opening <NUM>. Additionally or alternatively, the anvil assembly <NUM> may be moved away from the anvil buttress loading tool <NUM> in directions opposite arrows "A" and "B.

After the anvil buttress loading tool <NUM> is separated from the anvil assembly <NUM>, as seen in <FIG> and <FIG>, a proximal portion 70a of the anvil buttress <NUM> is retained on the anvil assembly <NUM> through engagement of the pin assembly <NUM> capturing the proximal tab <NUM> between the retaining pins <NUM> and the groove <NUM> of the anvil plate <NUM>, and a distal portion 70b of the anvil buttress <NUM> is retained on the anvil assembly <NUM> by engagement of the distal tab <NUM> with the notches 58b of the anvil tip <NUM> through the distal window <NUM>.

As shown in <FIG>, in conjunction with <FIG>, the surgical stapling apparatus <NUM>, with the anvil assembly <NUM> loaded with the anvil buttress <NUM>, is ready for use. In aspects, the staple cartridge assembly <NUM> is pre-loaded and/or loaded with a cartridge buttress (not explicitly shown). The cartridge buttress may be releasably secured to the staple cartridge assembly <NUM> via any suitable attachment feature within the purview of those skilled in the art, such as, for example, mechanical attachment features (e.g., sutures, pins), chemical attachment features (e.g., adhesive), and/or attachment methods (e.g., welding).

In operation, with the tool assembly <NUM> loaded with the anvil buttress <NUM>, as described above, the surgical stapling apparatus <NUM> is used in accordance with methods known by those skilled in the art. Once the staple cartridge and anvil assemblies <NUM>, <NUM> are clamped onto tissue, the surgical stapling apparatus <NUM> is fired, thereby stapling the anvil buttress <NUM> to the tissue, as well as cutting and dividing the tissue and the anvil buttress <NUM> disposed between the rows of formed staples. When firing is complete and the staple cartridge and anvil assemblies <NUM>, <NUM> are unclamped, the anvil buttress <NUM>, which is now stapled to the tissue, pulls away from the anvil assembly <NUM>, and the tool assembly <NUM> can be removed from the surgical site. In some aspects, the used staple cartridge <NUM> may be removed from the tool assembly <NUM> and replaced with a new staple cartridge <NUM> and, in some other aspects, the loading unit <NUM> may be replaced with a new loading unit <NUM>. A new anvil buttress <NUM> may be installed onto the anvil assembly <NUM> by an anvil buttress loading tool <NUM>, as needed or desired, as described above.

Claim 1:
An anvil buttress loading system comprising:
an anvil assembly (<NUM>) including an anvil plate (<NUM>) and an anvil tip (<NUM>), the anvil plate having a tissue facing surface (<NUM>), a proximal end portion of the tissue facing surface including a pin assembly (<NUM>);
an anvil buttress loading tool (<NUM>) including a base (<NUM>) having a support surface (<NUM>), a loading ramp (<NUM>) extending proximally of the base, and a flange (<NUM>) extending distally from the base; and
an anvil buttress (<NUM>) including a body (<NUM>), a proximal tab (<NUM>) extending proximally from the body, and a distal tab (<NUM>) extending distally from the body,
the anvil buttress (<NUM>) releasably retained on the anvil buttress loading tool (<NUM>) with the body (<NUM>) positioned on the support surface (<NUM>), the proximal tab (<NUM>) positioned over the loading ramp (<NUM>), and the distal tab (<NUM>) positioned within the flange (<NUM>), the anvil buttress transferrable from the anvil buttress loading tool to the anvil assembly such that the anvil buttress is releasably secured to the anvil assembly with the body positioned on the tissue facing surface, the proximal tab engaged with the pin assembly (<NUM>), and the distal tab engaged with the anvil tip (<NUM>).