Variable compression surgical fastener apparatus

[0001] This application claims priority from provisional application Ser. No. 61/044,689, filed Apr. 14, 2008, the entire contents of which are incorporated herein by reference.

[0002] 1. Technical Field

[0003] The present disclosure relates to surgical fastener applying apparatus. More particularly, the present disclosure relates to a fastener applying assembly that includes a plurality of two-part surgical fasteners configured to apply varying compressive forces to tissue.

[0004] 2. Background of the Related Art

[0005] Many varieties of surgical fastening apparatus are known in the art, some of which are specifically adapted for use in various surgical procedures including, but not limited to, end-to-end anastomosis, circular end-to-end anastomosis, open gastrointestinal anastomosis, endoscopic gastrointestinal anastomosis, and transverse anastomosis. U.S. Pat. Nos. 5,915,616, 6,202,914, 5,865,361, and 5,964,394 each describe one or more suitable apparatus which may be employed while performing one of these procedures.

[0006] In general, a surgical fastening apparatus will include an anvil that is approximated relative to a fastener cartridge during use or a fastener cartridge that is approximated relative to an anvil. The anvil includes depressions that are aligned with, and/or are in registration with slots defined in the cartridge, through which the fasteners will emerge, to effectuate formation. In other apparatus, the anvil contains a plurality of retainers with apertures to receive legs of the fasteners. The fastener cartridge typically has one or more rows of fasteners disposed laterally or radially of a channel that is configured to accommodate a knife, or other such cutting element, such that tissue can be simultaneously cut and joined together. Depending upon the particular surgical fastening apparatus, the rows of fasteners may be arranged in a linear or non-linear, e.g. circular, semi-circular, or otherwise arcuate configuration.

[0007] Various types of surgical fasteners are well known in the art, including but not limited to unitary fasteners and two-part fasteners. Unitary fasteners generally include a pair of legs adapted to penetrate tissue and connected by a backspan from which they extend. In use, subsequent to formation, some of the unitary fasteners have a “B” configuration. Typically, the two-part fasteners include legs that are barbed and connected by a backspan which are engaged and locked into a separate retainer piece that is usually located in the anvil. In use, the two-part fastener is pressed into the tissue so that the barbs penetrate the tissue and emerge from the other side where they are then locked into the retainer piece. The retainers prevent the two-part fastener from dislodging from the tissue. The two-part fasteners are not intended to be unlocked or removable and are generally made of a bioabsorbable material.

[0008] During each of the aforementioned surgical procedures, the tissue is initially gripped or clamped between the cartridge and anvil such that individual fasteners can be ejected from the cartridge, through the slots, and forced through the gripped tissue. Thereafter, the fasteners are formed by driving them into the depressions formed on the anvil or into the apertures of the retainers.

[0009] A common concern in each of these procedures is hemostasis, or the rate at which bleeding of the target tissue is stopped. It is commonly known that by increasing the amount of pressure applied to a wound, the flow of blood can be limited, thereby decreasing the time necessary to achieve hemostasis. To this end, conventional surgical fastening apparatus generally apply two or more rows of fasteners about the cut-line to compress the surrounding tissue in an effort to stop any bleeding and to join the cut tissue together. Each of the fasteners will generally apply a compressive force to the tissue sufficient to effectuate hemostasis, however if too much pressure is applied, this can result in a needless reduction in blood flow to the tissue surrounding the cut-line. Accordingly, the joining of tissue together in this manner may result in an elevated level of necrosis, a slower rate of healing, and/or a greater convalescence.

[0010] Consequently, it would be advantageous to provide a surgical fastening apparatus capable of limiting the flow of blood in the tissue immediately adjacent the cut tissue to effectuate hemostasis and wound closure, while maximizing blood flow in the surrounding tissue to facilitate healing.

[0011] Additionally, when tissue is clamped and compressed between the anvil and cartridge, some of the fluid of the tissue is squeezed out so the tissue is compressed further at the center portions of the cartridge and anvil than at the lateral edges, thereby leaving thicker tissue at the edges. It would therefore be advantageous to provide staples which could better accommodate these resulting different tissue thicknesses.

[0012] The present disclosure provides in one aspect a surgical fastener applying apparatus comprising a fastener supporting portion and a retainer supporting portion. The fastener supporting portion includes a first row of first surgical fasteners and a second row of second surgical fasteners. The retainer supporting portion includes a first row of first retainers and a second row of second retainers, the first fasteners engagable with the first retainers and the second fasteners engagable with the second retainers. The first fasteners each have a first fastener backspan and the second fasteners each have a second fastener backspan, and the first retainers each have a first retainer backspan and the second retainers each have a second retainer backspan. The fasteners and retainers are configured so that when engaged a first distance between at least one of the first fastener backspans and respective first retainer backspan is different than a second distance between at least one of the second fastener backspans and respective second retainer backspan.

[0013] Preferably, the first row of fasteners is positioned inboard of the second row of fasteners and the first distance is less than the second distance. The apparatus may also include a third row of third fasteners and a third row of third retainers, wherein the third row of fasteners is positioned outboard of the second row of fasteners and the second distance is less than a distance between a backspan of at least one of the third fasteners and a backspan of a respective third retainer.

[0014] In some embodiments, the backspan of at least one of the first fasteners has a greater height than the backspan of at least one of the second fasteners, the first row of fasteners being positioned closer to a central longitudinal axis of the fastener supporting portion than the second row of fasteners. In some embodiments, the backspan of at least one of the first retainers has a greater height than the backspan of at least one of the second retainers, and the first row of retainers is positioned closer to a central longitudinal axis of the retainer supporting portion than the second row of retainers.

[0015] The apparatus may further include a third row of third fasteners and a third row of third retainers, wherein the third row of fasteners is positioned further from the central longitudinal axis than the second row of fasteners, and a height of a backspan of at least one of the third retainers is less than a height of the backspan of at least one of the second retainers.

[0016] In some embodiments, the retainer supporting portion and fastener supporting portion are pivotally attached. In other embodiments, at least one of the retainer supporting portion and fastener supporting portion is movable along a substantially linear path to move the retainer supporting portion and fastener supporting portion into approximation.

[0017] The first and second rows of fasteners can be arranged in a substantially annular configuration. The first and second rows of fasteners can also be arranged in a substantially linear configuration.

[0018] The present disclosure provides in another aspect a surgical fastener applying apparatus comprising a fastener assembly having a first pair of first rows of fasteners and a second pair of second rows of fasteners and a corresponding first pair of rows of retainers and a second pair of rows of retainers to receive the respective fasteners. At least one of the fasteners and retainers of the first pair of rows of fasteners and retainers is configured so when engaged applies a first compressive force on tissue and at least one of the fasteners and retainers of the second pair of rows of fasteners and retainers is configured so when engaged applies a second different compressive force on tissue.

[0019] Preferably the first pair of rows of fasteners is positioned closer to a central longitudinal axis of the fastener assembly and the first compressive force is greater than the second compressive force. In a preferred embodiment, a distance between the fastener backspan and retainer backspan is less in a plurality of fasteners in the first fastener row than in a plurality of fasteners in a second fastener row.

[0020] The present disclosure provides in another aspect a surgical fastener applying cartridge and anvil assembly for use with a surgical fastener applying instrument. The cartridge and anvil assembly include a cartridge having a first pair of rows of fasteners and a second pair of rows of fasteners and the anvil assembly includes a first pair of rows of first retainers and a second pair of rows of second retainers to receive the respective fasteners. At least one of the fasteners and retainers of the first pair of rows is configured so when engaged applies a first compressive force on tissue and at least one of the fasteners and retainers of the second pair of rows is configured so when engaged applies a second different compressive force on tissue.

[0021] Preferably, the first pair of rows of fasteners is positioned closer to a central longitudinal axis of the fastener assembly and the first compressive force is greater than the second compressive force. Preferably, a distance between the fastener backspan and retainer backspan is greater between at least one of the fasteners and retainers in the second row than between at least one of the fasteners and retainers in the first row.

[0036] Various exemplary embodiments of the presently disclosed surgical fastener applying assembly 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 surgical fastener cartridge that is closer to the operator during use, while the term “distal” will refer to the end of the fastener cartridge that is further from the operator, as is traditional and conventional in the art. In addition, the term “surgical fastener” should be understood to include any substantially rigid structure formed of a biocompatible material that is suitable for the intended purpose of joining tissue together, including but not being limited to fasteners engaging retainers, surgical staples, clips, and the like.

[0037] The present disclosure provides a fastener applying assembly adapted to house a plurality of two-part surgical fasteners providing varying degrees of compressive force to fastened tissue occupied therein such that an effective hemostatic effect at or near the cut-line may be achieved. To this end, the two-part surgical fasteners are configured such that the two-part surgical fasteners deployed closer to the cut line produce a greater compressive force to fastened tissue than the surgical fasteners deployed further from the cut line.

[0038] As noted, two-part fasteners typically include a fastener and a retainer to which the fastener is deployed into. The preferred fastener and retainer are composed of a bioabsorbable polymeric material, such as polymers or copolymers of glycolide, lactide, p-dioxanone, polyester, polyamino acids and the like, the preferred construction of which is shown and described in U.S. Pat. No. 4,932,960, which is hereby incorporated by reference.

[0039] With reference initially to FIG. 1, one type of surgical fastener applying apparatus 1000 that employs a fastener applying assembly 1006 is illustrated. Surgical fastener applying apparatus 1000 is used to sequentially apply a plurality of surgical fasteners to a patient's tissue. Surgical fastener apparatus 1000 may be configured for use, subsequent sterilization and reuse, although it is preferably configured for single use. Surgical fastener applying apparatus 1000 includes a handle 1002, an elongated shaft or endoscopic portion 1004 extending distally therefrom, and an assembly 1006 coupled to a distal end 1008 of the elongated shaft 1004. In general, assembly 1006 is adapted to clamp, sequentially fasten together, and sever adjacent tissue segments along a cut-line. Assembly 1006 includes a pair of opposed jaws 1010, 1012 pivotally coupled to one another and respectively including an anvil member or retainer supporting portion 500 that is approximated relative to a surgical fastener cartridge or fastener supporting portion 100 during use. The retainer supporting portion 500 includes retainers that are aligned in registration with slots 126 defined in the cartridge 100, through which a surgical fastener 130 will emerge, to effectuate formation as it engages the retainer. For a more detailed discussion of the approximation and firing of surgical fastener applying apparatus 1000, reference is made to commonly owned U.S. Pat. No. 5,865,361, currently assigned to Tyco Healthcare Group LP, the entire contents of which is incorporated herein by reference. In preferred embodiments, cartridge 100 containing the fasteners and anvil 500 containing the retainers are removable and replaceable with another loaded cartridge and anvil.

[0040] While assembly 1006 is depicted as an apparatus suitable for use in laparoscopic procedures for performing surgical anastomotic fastening of tissue, those skilled in the art will appreciate that cartridge 100 and retainer supporting portion 500 may be adapted for use with any surgical instrument suitable for the intended purposes described herein. For example, assembly 1006 may be adapted for use with an end-to-end anastomosis device 2000, as seen in FIG. 2, wherein the fasteners and retainers are arranged in substantially annular rows and/or a surgical stapling instrument 3000, as seen in FIG. 3, for use during an open gastro-intestinal anastomotic stapling procedure wherein the fasteners and retainers are arranged in substantially linear rows, or, for example, any of the surgical fastener applying apparatus discussed in U.S. Pat. Nos. 6,045,560; 5,964,394; 5,894,979; 5,878,937; 5,915,616; 5,836,503; 5,865,361; 5,862,972; 5,817,109; 5,797,538; and 5,782,396, which are each incorporated by reference herein in their entirety.

[0041] For the purposes of brevity, the structural and operational features of assembly 1006 will be described in terms of use with the surgical fastener applying apparatus 1000.

[0042] With reference to FIG. 4, cartridge 100 of assembly 1006 is shown. Cartridge 100 extends along a longitudinal axis “A-A” and includes a cartridge body 112 with a pair of side walls 114, 116, a bottom wall 118, and a top wall 120. The top wall 120 includes a channel 122 that is configured to accommodate longitudinal movement of a knife (not shown), or other suitable cutting element, such that fastened tissue may be severed along a cut-line. The top wall 120 further includes a tissue engaging surface 124 (e.g., for maintaining the position of the tissue to be cut) and a plurality of fastener retention slots 126 arranged into a plurality of substantially linear rows 128. As shown in FIG. 4, the fastener retention slots 126 are arranged into a pair of first (inner) rows 128_A that are spaced laterally from the channel 122 and on opposite sides thereof, a pair of second (middle) rows 128_B that are spaced laterally (outboard) from the pair of first rows 128_A and on opposite sides of the channel 122, and a pair of third (outer) rows 128_C that are spaced laterally (outboard) from the pair of second rows 128_B and on opposite sides of channel 122. Rows 128_A, 128_B, and 128_C are in alignment and/or vertical registration with a plurality of corresponding rows 428 of anvil 500, to be described in greater detail below. While the cartridge 100 is depicted as including pairs of first, second, and third rows 128_A, 128_B, 128_C, respectively, it is within the purview of the present disclosure to have more or fewer rows of the fasteners (and corresponding rows of retainers). Additionally, rows of fasteners (and corresponding rows of fastener retainers) may extend radially from the cutting element arranged in substantially annular rows, such is the case when the surgical fastening assembly is employed with the surgical fastening device depicted in FIG. 2.

[0043] Each of the fastener retention slots 126 is configured to receive one of a plurality of surgical fasteners 130 and pushers 150 therein such that the surgical fasteners 130 are deployed in rows (e.g., inner, middle, and outer rows) on opposite sides of the cut-line created in the tissue during fastening, as shown in FIG. 11.

[0044] For a more detailed description of the functional and structural features of cartridge 100, reference is made to commonly owned U.S. Pat. Nos. 5,653,373 and 5,573,169 the disclosures of which are incorporated by reference herein.

[0045] With reference now to FIGS. 5, 6 and 7A-7D, cartridge 100 is loaded with one or more varieties of surgical fastener 130, represented generally as surgical fastener 130. Surgical fastener 130 of cartridge 100 is configured such that the surgical fastener 130 deployed closer to the cut line provides a greater compressive force to the fastened tissue than the surgical fastener 130 deployed further from the cut line. To this end, surgical fastener 130 includes two legs 132 connected by a backspan 134 extending therebetween with the thickness of backspan 134 varied such that the surgical fastener 130 closer to the cut line provides a greater compressive force to fastened tissue occupied therein than the surgical fastener 130 further from the cut line. The thickness of the legs 132 can also be varied to this end. The thickness of the backspan 134 and the thickness of the legs 132 may also be varied to fasten adjacent tissue segments “T₁”, “T₂” of varying thickness.

[0046] The legs 132 and the backspan 134 may define a cross-section having any suitable geometric configuration, including but not limited to rectangular, oval, square, triangular, and trapezoidal. The legs 132 and the backspan 134 may exhibit the same geometrical configuration such that the cross-sectional configuration of the surgical fastener 130 is substantially uniform, as shown in FIG. 6, or, alternatively, the legs 132 and the backspan 134 may exhibit different geometrical configurations, e.g., the legs 132 may exhibit a rectangular cross-section and the backspan 34 may exhibit an oval cross-section, as shown in FIGS. 7A-7D, discussed in more detail below. Backspan 134 and/or legs 132 may be formed by any suitable methods known in the art including but not limited to welding, braising, coining, casting, molding, overmolding and so on. Additionally, backspan may include different configurations of blocking and/or retainer material, tube, sleeve, collar, and/or grommet.

[0047] As seen in FIGS. 5 and 6, legs 132 of the fastener extend from the backspan 134 such that they are substantially parallel. Alternatively, the legs 132 may converge or diverge from the backspan such that they are positioned at an acute or obtuse angle with respect to the backspan.

[0048] Each of the legs 132 preferably terminates in a generally spear shaped penetrating end 136 that is configured to penetrate tissue (tissue segments “T₁”, “T₂” for example) and/or other suitable material (retainer material for example). Penetrating end 136 is dimensioned for forced entry into a pair of apertures 206 of a retainer 200, to be described in greater detail below. The penetrating ends 136 of legs 132 can be tapered to facilitate the penetration of tissue segments “T₁”, “T₂”, or alternatively, the penetrating ends 136 may not include a taper. In some embodiments, penetrating ends 136 may define a conical or flat surface. In various embodiments, one or both of legs 132 may be barbed, as best seen in FIGS. 9, 10A-10C, and 11 for example. Having legs 132 configured in such a manner may facilitate maintaining the surgical fastener 130 in a fixed position within retainer 200. Located on one or both of legs 132 may be one or more raised bumps 103 (FIG. 5). Bumps 103 are configured to help retain fastener 130 within retainer 200 after entry has been completed. While bumps 103 are shown at two locations, bumps 103 may also be provided on a rear face of fastener 130 (not shown) to retain the fastener.

[0049] As noted, retainers 200 are configured for joining with surgical fasteners 130 upon firing of the surgical fastener 130. With this purpose in mind, the retainers 200 are each positioned within the plurality of retainer rows 428 opposite the plurality of fastener rows 128 when the assembly 1006 is assembled, as best seen in FIG. 11.

[0050] With reference back again to FIG. 5, retainer 200, a retainer holder 300 and a retainer holder cartridge 400 of anvil 500 are shown. Retainer 200 includes a backspan 202, having a height “H”, extending between retainer legs 203, and is securely positioned on retainer holder 300. Retainer holder 300 includes one or more upstanding posts 300a, 300b, 300c, and 300d which are dimensioned and configured to enter apertures 204 of retainer 200 on the side opposite the fastener 130 entry side. Each retainer holder 300 supports two retainers 200. The upright posts 300a, 300b, 300c and 300d each have a sloped side which is angled slightly off the vertical such that the top of the upright post is slightly narrower than the bottom. The tapering facilitates the entry and removal of the upright posts from retainer apertures 206. The retainer holder 300 provides a stable flat base for retainer 200 and disengages from the retainer 200 when fastener portion 130 engages the retainer 200. During operation, fasteners 130 are deployed from cartridge 100 to mate with their respective retainers 200.

[0051] Retainer holder 300 is operatively connected to a retainer holding cartridge 400. Retainer holding cartridge 400 is an elongated generally arcuately shaped piece that is adapted to hold retainer holders 300 in a frictional fitting such that they are frictionally supported in an initial upper position wherein the retainer holders 300 are engaged with the retainers 200. In some embodiments, the retainer holders 300 may be slightly curved along their sides to match the curvature of the cartridge 400 so as to be downwardly slidable when forced out of engagement with the retainers 200 by the entering tips 136 of the fastener 130.

[0052] Retainers 200 are initially in the position illustrated in FIG. 8A. Retainer 200 is located on the upper chamber of retainer holding cartridge 400, and mounted on retainer holder 300 by means of the posts which are inserted into the apertures 204 (FIG. 5) at the bottom of the retainer 200. A portion of the bottom of the retainer 200 overlaps the edge of base 302 such that the overlapping portion rests on a shelf 412 of retainer holding cartridge 400 (FIG. 8A).

[0053] Turning now to FIG. 8B, a surgical fastener 130 and a retainer 200 are shown subsequent to entry. When the fasteners 130 are inserted into retainers 200, the barbed tips 136 of the fasteners push down on the upright posts, e.g., post 300a, thereby pushing the retainer mounting element 300 down into a position where it is no longer in engagement with the retainer 200. The retainers 200 are dimensioned and configured to be supported by shelves 412 such that they are braced against downward movement. Upon disengagement with the retainer holders 300, the retainers 200 are free to be lifted out of the cartridge 400 in engagement with the fasteners. Reference is made to commonly assigned U.S. Pat. No. 5,653,373 for a more detailed description of the structural and operative features of the retainer 200, retainer holder 300 and retainer holder cartridge 400 of anvil 500.

[0054] With reference to FIG. 9, surgical fastener 130 and retainer 200 are shown subsequent to entry/engagement (or formation) with adjacent tissue segments occupied therein. As noted, the two-part surgical fastener includes surgical fastener 130 and retainer 200 configured to provide a compressive force to fastened tissue occupied therein i.e. in the space between the backspan 202 of retainer 200 and the backspan 134 of fastener 130. To this end, surgical fastener 130 cooperates with retainer 200 to maintain adjacent tissue segments “T₁”, “T₂” in approximation and apply a compressive force “F” thereto. The compressive force “F” applies pressure to the tissue segments “T₁”, “T₂”, thereby restricting the flow of blood through the tissue surrounding the surgical fastener 130 and retainer 200 and facilitating hemostasis. The configuration of the backspan 134 of surgical fastener 130 and the retainer 200 may limit the amount of pressure that can be applied to the tissue segments “T₁”, “T₂” such that the flow of blood through the tissue is not completely restricted. When joined, the surgical fastener 130 and retainer 200 will form an enclosure that has an overall tissue compression space 140, defined between the inner surface 135 (or upper surface as viewed in the orientation of FIG. 9) of the backspan 134 of the fastener 130 and the inner surface 207 (or lower surface as viewed in the orientation of FIG. 9) of the backspan 202 of the retainer 200.

[0055] With reference to FIGS. 10A-10C, surgical fastener 130 will be described in terms of surgical fasteners 130_A, 130_B, and 130_C, and retainer 200 will be described in terms of retainers 200_A, 200_B, and 200_C. Surgical fasteners 130_A, 130_B, and 130_C and their respective retainers 200_A, 200_B, and 200_C are shown in their formed (or fully joined/engaged) conditions. Surgical fasteners 130_A, 130_B, 130_C, are preferably substantially similar to each other; however, the retainers 200_A, 200_B, and 200_C differ as described below. Alternatively, surgical fasteners 130_A, 130_B, 130_C may have varying height backspans. These varying height fastener backspans can be provided in addition to the varying height retainer backspans or instead of the varying height retainer backspans. Having the surgical fasteners 130 and/or retainers 200 configured in such a manner with varying backspans may increase hemostasis of fastened tissue when the two-part fastener is formed.

[0056] The overall heights of the joined fasteners 130_A, 130_B, 130_C and respective retainers 200_A, 200_B, and 200_C (measured from the outer surface of the retainer backspan 202 to the outer surface of the fastener backspan 134) are preferably substantially the same, however, the compression spaces vary due to the variations in the retainer backspan. That is, the respective dimensions “H₁”, “H₂”, and/or “H₃” of backspan 202_A, 202_B, 202_C of retainer 200_A, 200_B, and 200_C, may be altered, which, in turn, may alter the dimensions of the compression spaces 140_A, 140_B, 140_C occupied by fastened tissue segments “T₁”, “T₂” when the respective surgical fasteners 130_A, 130_B, 130_C and retainers 200_A, 200_B, and 200_C are in their joined (engaged) formation. By altering the respective height (thickness) “H₁”, “H₂”, and/or “H₃” any desired level of hemostasis and blood flow in the fastened tissue segments “T₁”, “T₂” may be effectuated. Other various attributes of the tissue (e.g., thickness or the presence of scar tissue) may increase or diminish the level of hemostasis and blood flow in the fastened tissue segments. It should be appreciated that portions of the retainer 200 extending from the backspan in which the apertures 206 are formed (the “aperture portion” of the backspan) have a thickness N (see FIG. 9).

[0057] Retainer 200c includes backspan 202_C that extends towards apertures 206 (discussed above in conjunction with FIG. 5) and has a height “H₃”. When the retainer 200_C and surgical fastener 130_C are joined (FIG. 10C) within tissue segments “T₁”, “T₂”, the surgical fastener 130_C and retainer 200_C will form an enclosure that has an overall tissue compression space 140_C (FIG. 10C). Compression space or zone 140_C provides minimal blood flow restriction when the tissue segments are fastened together.

[0058] Retainer 200_B includes backspan 202_B that extends towards apertures 206 and has a height “H₂”. When the retainer 200_B and surgical fastener 130_B are joined (FIG. 10B) within tissue segments “T₁”, “T₂”, the surgical fastener 130_B and retainer 200_B will form an enclosure that has an overall tissue compression space 140_B (FIG. 10B). The compression space 140_B is less than the compression space 140_C of fastener 130_C. Accordingly, because the pressure exerted on the tissue segments “T₁”, “T₂” by retainer 200_B and surgical fastener 130_B is greater than the pressure exerted on the tissue segments “T₁”, “T₂” by surgical fastener 130_C, the blood flow through the tissue surrounding surgical fastener 130_B will be less (more restricted) than the blood flow through the tissue surrounding surgical fastener 130_C, thereby further facilitating hemostasis. However, because blood flow is not completely restricted through tissue compression space 140_B, unnecessary necrosis of the fastened tissue may be prevented and/or impeded. Note also that the thickness of the aperture portions of the retainer 200b is greater along a larger distance than the thickness of the aperture portions of the retainer 200c due to the increased backspan thickness/height.

[0059] Retainer 200_A includes backspan 202_A that extends towards apertures 206 and has a height “H₁”. When the retainer 200_A and surgical fastener 130_A are joined (FIG. 10A) within tissue segments “T₁”, “T₂”, the surgical fastener 130_A and retainer 200_A will form an enclosure that has an overall tissue compression space 140_A (FIG. 10A). The compression space 140_A is less than the compression space 140_B of fastener 130_B. Accordingly, because the pressure exerted on the tissue segments “T₁”, “T₂” by retainer 200_A and surgical fastener 130_A is greater than the pressure exerted on the tissue segments “T₁”, “T₂” by retainer 200_B and surgical fastener 130_B, and retainer 200_C and surgical fastener 130_C, the blood flow through the tissue surrounding retainer 200_A and surgical fastener 130_A will be less (more restricted) than the blood flow through the tissue surrounding surgical fasteners retainer 200_B and surgical fastener 130_B and the tissue surrounding retainer 200_C and surgical fastener 130_C, thereby further facilitating hemostasis. Because blood flow is substantially and/or completely restricted through tissue compression space 140_A, this results in further facilitating and effectuating hemostasis.

[0060] FIG. 11 illustrates the surgical fasteners 130_A, 130_B, and 130_C and their respective retainers 200_A, 200_B, and 200_C loaded within the cartridge 100 and anvil 500, respectively, of the assembly 1006 shown in FIGS. 1 and 4. The surgical fasteners 130_A, 130_B, and 130_C and their respective retainers 200_A, 200_B, and 200_C are each arranged within inner, middle, and outer rows of cartridge 100 and anvil (retainer supporting portion) 500 respectively. As noted, rows 128_A, 128_B, and 128_C of cartridge 100 and corresponding rows 428_A, 428_B, and 428_C of anvil 500 are each spaced laterally from the channel 122, on opposite sides thereof, such that the surgical fasteners 130_A, 130_B, and 130_C, and retainers 200_A, 200_B, and 200_C will be deployed on opposite sides of the cut-line (not shown) created in the tissue upon fastening. That is, the retainers 200_A with the largest height (or thickness) backspan provide a greater compressive force as there is a shorter distance between their backspan and the backspan of the respective fastener, and in the illustrated embodiment are provided in the inner rows closer to the cut line. The retainers 200_B have a greater distance between their backspan and the backspan of the respective fastener and are provided on the outer rows (outboard of the rows of retainers 200_A) where the tissue might be thicker as a result of clamping by the instrument jaws (anvil and cartridge). If a third row of fasteners 130_C is used in this embodiment, then the retainers of FIG. 10C with the smallest height backspan (largest compression space) would preferably be placed on the outermost row furthest from the cut line. By providing the rows of fasteners which provide greater tissue compression as you approach the cut line, a greater range of tissue thicknesses can be effectively sealed by the same cartridge. It should be appreciated however, that the retainers can be placed on other rows than the foregoing. Also, while the inner, middle and outer rows 128_A, 128_B, and 128_C of cartridge 100 and corresponding rows 428_A, 428_B, and 428_C of anvil 500 are shown as including the surgical fasteners 130_A, 130_B, 130_C and retainers 200_A, 200_B, and 200_C, respectively, the present disclosure contemplates the inclusion of the fasteners and retainers in other rows or arrangement of any of the surgical fasteners 130_A, 130_B, and 130_C and their corresponding retainers 200_A, 200_B, and 200_C, disclosed hereinabove, either exclusively, such that only a single surgical fastener and retainer, e.g., surgical fastener 130_A and retainer 200_A, is present in a particular row, or in combination, such that a variety of surgical fasteners, e.g., surgical fasteners 130_A, 130_B, and 130_C and retainers 200_A, 200_B, and 200_C are present in on more of the rows.

[0061] In one particular embodiment, the outer rows 128_C, intermediate rows 128_B, and inner rows 128_A of cartridge 100, and outer rows 428_C, intermediate rows 428_B, and inner rows 428_A of anvil 500 are comprised solely of surgical fasteners 130_C, 130_B, and 130_A and their corresponding retainers 200_C, 200_B, and 200_A, respectively, such that the flow of blood through the tissue immediately surrounding the cut-line (not shown) is substantially, if not completely, restricted by joined surgical fastener 130_A and retainer 200_A, whereas the flow of blood through the tissue surrounding the intermediate and outer rows along the cut-line are less restricted by joined surgical fasteners 130_B, 130_C and retainers 200_B, 200_C, respectively. Accordingly, the flow of blood is minimized in the tissue immediately adjacent the cut-line and is increased gradually as the lateral distance from the cut-line is also increased. Also by this arrangement, the retainers with the largest height backspan (retainers 200_A), are closest to the cut line where the tissue is generally compressed to the greater extent and the retainers with the smaller height backspan are positioned in the outer rows where the tissue is thicker. It should be appreciated that the height of the backspans could be varied to accommodate tissue of different thicknesses and to control tissue compression by the fasteners.

[0062] In the embodiments of FIGS. 7A-7D, various backspans of the surgical fastener are disclosed. In FIG. 7A, the backspan is an integral element 634 in which the fastener legs 632 are embedded. In FIG. 7C, the backspan 934 is integral with the fastener legs 932 and has a curved outer and inner surface. In the embodiments of FIGS. 7B and 7D, a separate backspan material is attached to the fastener 730, 830, respectively, with backspan 734 of FIG. 7B being in the form of a cylindrical collar encircling the backspan portion 731 of the fastener 730 and the backspan 834 of fastener 830 of FIG. 7D encompassing the backspan portion 831 of the fastener and a portion of the fastener legs 832. The backspan material of FIGS. 7B and 7D can be composed of thermoplastic overmolded onto the staple wire, by way of example. Varying the thickness or height of these backspans or backspan materials can vary the compressive force of the formed staple by varying the distance between the backspan of the fastener and the backspan of the retainer when engaged. FIG. 7B illustrates this by showing in phantom a collar of larger diameter to decrease the compression area when engaged with a retainer. Other backspan shapes and attachments to achieve the various compressive forces are also contemplated. It should be appreciated that varying height fastener backspans can be used with the varying height retainer backspans to vary the distance between the backspans to thereby vary the compression space and compressive force. It should also be appreciated that the varying height fastener backspans can be used with retainers of uniform height backspans to achieve the varying compression space and compressive force. (Varying height retainer backspans with uniform height fastener backspans were discussed in detail above).

[0063] 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 surgical fasteners described herein above may be formed from a variety of surgically acceptable materials including titanium, plastics, bio-absorbable materials, etc. Additionally, any of the aforementioned surgical fasteners may be treated, chemically or otherwise, prior to being loaded into cartridge 100.

[0064] It is also contemplated that the backspan 202 of the retainer 200 may include different configurations of tube, sleeve, collar, and/or grommet, such as those previously described with regard to the backspans of the surgical fastener.

[0065] The fasteners and retainers of surgical fastening cartridge 100 and anvil may also be employed with a surgical fastener applying apparatus 4000 (FIG. 12) that is used to simultaneously deploy a plurality of surgical fasteners (surgical fasteners 130 and retainers 200 for example), arranged in substantially linear rows transverse to a longitudinal axis of the apparatus, into either side of a target section of tissue (not explicitly shown). Here, a scalpel or other such cutting element may be used to remove the target section of tissue, or a built in knife could be provided which could be advanced upon advancement (firing) of the fasteners. The fasteners 130 would be supported within the cartridge or fastener supporting portion 4002 and the retainers would be supported within the anvil or retainer supporting portion 4004. Approximation of the cartridge and anvil, e.g. linear movement of the fastener supporting portion 4002 toward the retainer supporting portion 4004, via movement of lever 4006 clamps tissue therebetween. The fasteners can then be advanced into the retainers as described above upon squeezing of handle 4007, providing varying compressive forces on the tissue due to the varying backspan heights. Further details regarding the use and function of surgical fastener applying apparatus 4000 may be obtained through reference to U.S. Pat. Nos. 7,070,083 and 5,964,394 the entire contents of which are incorporated by reference herein. In an alternate embodiment, the apparatus 4000 could include a cutting element as in the other cartridges disclosed herein. Such staplers can also include other mechanisms for approximating the anvil and cartridge and firing the fasteners. The cartridge and anvil can also be used with other apparatus for simultaneously deploying a substantially linear row of fasteners, such as U.S. Pat. No. 7,407,076, the entire contents of which is incorporated herein by reference.

[0066] As noted above, the fasteners and retainers of surgical fastening cartridge 100 and anvil 500 may also be employed with a surgical fastener applying apparatus 3000 (FIG. 3) that is used to sequentially deploy a plurality of surgical fasteners (surgical fasteners 130 and retainers 200 for example), arranged in substantially linear rows substantially aligned with the longitudinal axis of the apparatus, into either side of a target section of tissue (not explicitly shown). Here, a knife is advanced with the firing of the fasteners. The fasteners 130 would be supported within the cartridge or fastener supporting portion 3002 and the retainers would be supported within the anvil or retainer supporting portion 3004. The instrument halves 3001 and 3003 are clamped together to approximate the cartridge and anvil, and movement of firing knob 3005 sequentially fires the fasteners into engagement with the retainers as described above, providing varying compressive forces on the tissue due to the varying backspan heights.

[0067] As noted above, the fasteners and retainers of surgical fastening cartridge 100 and anvil may also be employed with a surgical fastener applying apparatus 2000 (FIG. 2) that is used to simultaneously deploy a plurality of surgical fasteners (surgical fasteners 130 and retainers 200 for example), arranged in substantially annular rows, into either side of a target section of tissue (not explicitly shown). Here, a knife is advanced with the firing of the fasteners. The fasteners 130 would be supported within the cartridge or fastener supporting portion 2002 and the retainers would be supported within the anvil or retainer supporting portion 2004. Approximation of the cartridge and anvil, e.g. retraction of the anvil 2004 by rotation of approximation knob (wing nut) 2005 clamps tissue between the anvil 2004 and cartridge 2002. The fasteners can then be advanced into the retainers as described above by squeezing of handles 2007, providing varying compressive forces on the tissue due to the varying backspan heights.

[0068] As described herein, differing compression spaces or zones are created by varying the height of the backspan of the retainers of the two-part fasteners. It is also contemplated as described above, that alternatively, the height of the backspans of the fasteners of the two-part fasteners can be varied to alter the compression spaces. Alternatively, as described above, both the height of the retainer backspan and the height of the fastener backspan can be varied to alter the compression spaces of the two part fasteners.

[0069] 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.