VARIABLE COMPRESSION SURGICAL FASTENER CARTRIDGE
A surgical fastener cartridge is provided and includes a cartridge body having a tissue contacting surface that includes a plurality of fastener retention slots. A plurality of surgical fasteners is operatively disposed in the plurality of fastener retention slots. A plurality of pushers is operably associated with the plurality of surgical fasteners. Each pusher is configured for ejecting an associated surgical fastener towards a depression in an anvil. An actuation sled is housed within the cartridge body and includes a plurality of cam wedges. The plurality of cam wedges configured to sequentially contact the plurality of pushers such that a surgical fastener that is ejected closer to a cut line produces a greater compression force to stapled tissue than a surgical fastener ejected further from the cut line.
1 . A surgical fastener applying apparatus comprising:
a fastener assembly including an anvil section and a cartridge section, the cartridge section and the anvil section movable from an unclamped position to a clamped position to clamp tissue therebetween, the cartridge section having a plurality of retention slots;
a plurality of first surgical fasteners and a plurality of second surgical fasteners, each surgical fastener disposed within a corresponding retention slot, the plurality of first surgical fasteners having a first backspan with a first thickness and the plurality of second surgical fasteners having a second backspan with a second thickness, wherein the first thickness is different than the second thickness.
2 . The surgical fastener applying apparatus according to claim 1 , wherein the first thickness applies a first compressive force to tissue upon formation of the plurality of first surgical fasteners and the second thickness applies a second compressive force to tissue upon formation of the plurality of second surgical fasteners.
3 . The surgical fastener applying apparatus according to claim 1 , wherein the first backspan is enlarged with respect to the second backspan, the first backspan being an integral element in which fastener legs of the plurality of first surgical fasteners are embedded.
4 . The surgical fastener applying apparatus according to claim 1 , wherein the first backspan is a separate backspan material attached to the plurality of first surgical fasteners.
5 . The surgical fastener applying apparatus according to claim 1 , wherein the first backspan includes a cylindrical collar encircling a backspan portion of the first backspan.
6 . The surgical fastener applying apparatus according to claim 1 , further comprising an actuation sled capable of moving distally through the cartridge section, the actuation sled including at least one cam wedge.
7 . The surgical fastener applying apparatus according to claim 6 , wherein as the actuation sled travels through the cartridge distally, the at least one cam wedge drives the pushers in order to deploy the surgical fasteners and drive them against the anvil section.
8 . The surgical fastener applying apparatus according to claim 1 , wherein the cartridge section includes a longitudinal slot configured to allow longitudinal movement of a knife bar therethrough.
9 . The surgical fastener applying apparatus according to claim 8 , wherein the cartridge section includes a first inner row of retention slots and a first outer row of retention slots on a first side of the longitudinal slot, and a second inner row of retention slots and a second outer row of retention slots on a second side of the longitudinal slot, wherein each retention slot is aligned with a corresponding pusher and fastener.
10 . The surgical fastener applying apparatus according to claim 9 , wherein the surgical fasteners in the first inner row and the second inner row are the plurality of first surgical fasteners and the surgical fasteners in the first outer row and the second outer row are the plurality of second surgical fasteners, the first thickness of the first backspan being greater than the second thickness of the second backspan.
11 . The surgical fastener applying apparatus according to claim 9 , wherein the actuation sled includes a first inner cam wedge, a second inner cam wedge, a first outer cam wedge, and a second outer cam wedge, wherein the first inner wedge contacts the pushers in the first inner row of retention slots, the second inner cam wedge contacts the pushers in the second inner row of retention slots, the first outer cam wedge contacts the pushers in the first outer row of retention slots, and the second outer cam wedge contacts the pushers in the second outer row of retention slots.