Powered stapler having varying staple heights and sizes

Abstract

A loading unit of a powered surgical stapling instrument includes anvil and cartridge assemblies. The anvil assembly includes a first tissue contacting surface, and the cartridge assembly includes a second tissue contacting surface, a first plurality of staples, a second plurality of staples, and a plurality of pushers. The second tissue contacting surface defines a knife channel partitioning the second tissue contacting surface into first and second portions. Each of the first and second portions includes an inner tissue contacting surface and an outer tissue contacting surface. The inner tissue contacting surface defines a first row of retention slots. The inner tissue contacting surface and the first tissue contacting surface define a first tissue gap. The outer tissue contacting surface defines a second row of retention slots. The outer tissue contacting surface and the first tissue contacting surface define a second tissue gap larger than the first tissue gap.

What is claimed is: 
     
         1 . A powered surgical stapling instrument comprising:
 a powered handle assembly;   a powered adapter assembly releasably secured to the powered handle assembly; and   a loading unit releasably secured to the powered adapter assembly, the loading unit including:
 an anvil assembly including a first tissue contacting surface; and 
 a cartridge assembly movable relative to the anvil assembly between open and approximated positions, the cartridge assembly including:
 a second tissue contacting surface defining a knife channel, the second tissue contacting surface being stepped, the knife channel partitioning the second tissue contacting surface into first and second portions, each of the first and second portions including:
 an inner tissue contacting surface disposed adjacent the knife channel and defining a first row of retention slots, the inner tissue contacting surface and the first tissue contacting surface of the anvil assembly defining a first tissue gap; and 
 an outer tissue contacting surface disposed laterally outward of the respective inner tissue contacting surface and defining a second row of retention slots, the outer tissue contacting surface and the first tissue contacting surface of the anvil assembly defining a second tissue gap larger than the first tissue gap; 
 
 a first plurality of staples having a first unformed leg length, the first plurality of staples disposed in the first row of retention slots; 
 a second plurality of staples having a second unformed leg length longer than the first unformed leg length, the second plurality of staples disposed in the second row of retention slots; and 
 a plurality of pushers, each pusher of the plurality of pushers including first and second panels, the first and second panels configured to eject respective one of the first plurality of staples and one of the second plurality of staples through the second tissue contacting surface of the cartridge assembly. 
 
   
     
     
         2 . The powered surgical stapling instrument according to  claim 1 , wherein the first row of retention slots of the inner tissue contacting surface is axially offset from the second row of retention slots of the outer tissue contacting surface. 
     
     
         3 . The powered surgical stapling instrument according to  claim 1 , wherein the first panel has a height longer than the second panel. 
     
     
         4 . The powered surgical stapling instrument according to  claim 1 , wherein each pusher of the plurality of pushers further includes a base panel interconnecting the first and second panels. 
     
     
         5 . The powered surgical stapling instrument according to  claim 1 , wherein each of the first and second portions of the second tissue contacting surface of the cartridge assembly includes a transitioning portion interconnecting the respective inner and outer tissue contacting surfaces. 
     
     
         6 . The powered surgical stapling instrument according to  claim 5 , wherein the transitioning portion defines a slope configured to provide gradual compression on tissue when tissue is clamped between the anvil assembly and the cartridge assembly. 
     
     
         7 . The powered surgical stapling instrument according to  claim 1 , wherein the first tissue contacting surface of the anvil assembly is planar. 
     
     
         8 . The powered surgical stapling instrument according to  claim 7 , wherein the first tissue contacting surface of the anvil assembly defines a longitudinal channel in registration with the knife channel of the cartridge assembly. 
     
     
         9 . The powered surgical stapling instrument according to  claim 1 , wherein the inner and outer tissue contacting surfaces of the first and second portions of the second tissue contacting surface of the cartridge assembly are symmetric with respect to the knife channel of the cartridge assembly. 
     
     
         10 . The powered surgical stapling instrument according to  claim 1 , wherein the inner tissue contacting surfaces of the first and second portions of the second tissue contacting surface of the cartridge assembly are coplanar. 
     
     
         11 . The powered surgical stapling instrument according to  claim 1 , wherein the outer tissue contacting surfaces of the first and second portions of the second tissue contacting surface of the cartridge assembly are coplanar. 
     
     
         12 . The powered surgical stapling instrument according to  claim 1 , wherein the outer tissue contacting surfaces are parallel to the inner tissue contacting surfaces. 
     
     
         13 . The powered surgical stapling instrument according to  claim 1 , wherein the second tissue contacting surface of the cartridge assembly and the first tissue contacting surface of the anvil assembly define a varying tissue gap and are configured to apply pressure to tissue disposed therebetween, wherein an amount of pressure applied to a portion of tissue disposed on the inner tissue contacting surface of the cartridge assembly is greater than an amount of pressure applied to a second portion of tissue disposed on the outer tissue contacting surface of the cartridge assembly. 
     
     
         14 . A powered surgical stapling instrument comprising:
 a powered handle assembly;   a powered adapter assembly releasably secured to the powered handle assembly; and   a loading unit releasably secured to the powered adapter assembly, the loading unit including:
 an anvil assembly including a planar anvil surface defining a plurality of staple-forming depressions; and 
 a cartridge assembly, at least one of the anvil assembly or the cartridge assembly movable relative to the other between an open position and a pre-fire position, the cartridge assembly including:
 a tissue contacting surface defining a knife channel, the tissue contacting surface being stepped, the knife channel partitioning the tissue contacting surface into first and second portions, each of the first and second portions including a first tissue contacting surface and a second tissue contacting surface, the first tissue contacting surface including a first plurality of staple retention slots, the first tissue contacting surface and the planar anvil surface configured to apply a first pressure to tissue disposed therebetween in the pre-fire position, the second tissue contacting surface defining a second plurality of staple retention slots, the second tissue contacting surface and the planar anvil surface configured to apply a second pressure to tissue disposed therebetween in the pre-fire position, the second pressure being less than the first pressure; 
 a first plurality of unformed staples having a first leg length, the first plurality of unformed staples configured to be ejected through the first plurality of staple retention slots and into engagement with the plurality of staple-forming depressions of the anvil assembly to form a first plurality of formed staples; and 
 a second plurality of unformed staples having a second leg length, the second plurality of unformed staples configured to be ejected through the second plurality of staple retention slots and into engagement with the plurality of staple-forming depressions of the anvil assembly to form a second plurality of formed staples, the second leg length being longer than the first leg length. 
 
   
     
     
         15 . The powered surgical stapling instrument according to  claim 14 , wherein the first plurality of staple retention slots are arranged in a linear row. 
     
     
         16 . The powered surgical stapling instrument according to  claim 15 , wherein the second plurality of staple retention slots are arranged in a linear row. 
     
     
         17 . The powered surgical stapling instrument according to  claim 14 , wherein the first tissue contacting surfaces are disposed adjacent the knife channel. 
     
     
         18 . The powered surgical stapling instrument according to  claim 14 , wherein the second tissue contacting surfaces are disposed laterally outward of the respective first tissue contacting surfaces. 
     
     
         19 . The powered surgical stapling instrument according to  claim 14 , wherein each of the first and second portions of the tissue contacting surface of the cartridge assembly includes a transition panel interconnecting the respective first and second tissue contacting surfaces. 
     
     
         20 . The powered surgical stapling instrument according to  claim 14 , further comprising a plurality of pushers, each pusher including first and second panels configured to engage respective one of the first plurality of unformed staples and one of the second plurality of unformed staples. 
     
     
         21 . The powered surgical stapling instrument according to  claim 20 , wherein each pusher includes a base panel interconnecting the first and second panels. 
     
     
         22 . The powered surgical stapling instrument according to  claim 20 , wherein the first panel has a length longer than the second panel.