CN-112971898-B - Reload assembly with knife holder lock

Abstract

A surgical stapling apparatus includes a reload assembly including a dual pawl system to hold a knife holder of the reload assembly in a retracted position after firing of the stapling apparatus. The dual pawl system includes auxiliary and primary pawls to improve retention of the tool holder to minimize the likelihood of inadvertent re-advancement of the tool holder and annular knife.

Inventors

• David scumpley
• Christopher Penner

Assignees

• 柯惠LP公司
• 柯惠LP公司

Dates

Publication Date

20260421

Application Date

20201210

Priority Date

20201103

Claims (20)

1. 1.A surgical stapling device, comprising: An adapter assembly having a proximal end portion and a distal end portion, and A reload assembly supported on the distal end portion of the adapter assembly, the reload assembly comprising: a housing shell comprising an outer shell portion and an inner shell portion, the inner and outer shell portions defining an annular cavity; an auxiliary pawl supported within the housing shell; A staple cartridge secured to the housing shell and supporting a plurality of staples; a staple pusher defining a through-bore, the staple pusher being supported within the annular cavity and being movable from a retracted position to an advanced position to eject the plurality of staples from the staple cartridge; A knife holder supported within the through bore of the staple pusher and defining a central bore that receives the inner housing portion of the outer housing, the knife holder being movable about the inner housing portion between a retracted position and an advanced position, the knife holder defining a pocket that receives the auxiliary pawl when the knife holder is in the retracted position to block movement of the knife holder from the retracted position toward the advanced position, and An annular knife supported on the knife holder.
2. 2. The surgical stapling device of claim 1, further comprising a handle assembly on which the proximal end portion of the adapter assembly is supported.
3. 3. The surgical stapling device of claim 1, wherein said auxiliary pawl is longitudinally fixed to said housing shell.
4. 4. The surgical stapling device of claim 3, wherein the secondary pawl is resilient.
5. 5. The surgical stapling device of claim 3, wherein the auxiliary pawl is rigid.
6. 6. The surgical stapling device of claim 1, wherein said knife holder comprises an interior surface defining said central aperture of said knife holder, said interior surface of said knife holder supporting at least one primary pawl, said interior housing portion of said housing comprising an exterior surface defining at least one longitudinal groove that receives said at least one primary pawl, said at least one primary pawl having a proximal portion, a distal portion, and an abutment surface separating said proximal portion of said at least one longitudinal groove from said distal portion of said at least one longitudinal groove, wherein said at least one primary pawl moves into interference engagement with said abutment surface as said knife holder is moved from its retracted position toward its advanced position.
7. 7. The surgical stapling device according to claim 4, wherein the auxiliary pawl is in the form of a spring clip.
8. 8. The surgical stapling device of claim 1 wherein said knife holder includes a plurality of resilient longitudinal body portions defining said central aperture, each of said longitudinal body portions being spaced apart from an adjacent longitudinal body portion to define a longitudinal slot.
9. 9. The surgical stapling device of claim 8, wherein said pockets are defined in adjacent longitudinal body portions of said knife block and communicate with a respective one of said longitudinal slots such that said auxiliary pawls are aligned with said respective one of said longitudinal slots, said auxiliary pawls being movable into said respective one of said longitudinal slots upon movement of said knife block from its retracted position toward its advanced position.
10. 10. The surgical stapling apparatus according to claim 9, wherein the adapter assembly includes a knife driver adapted to be releasably coupled to the knife holder.
11. 11. The surgical stapling apparatus according to claim 10, wherein a width of the auxiliary pawl is greater than a width of the respective one of the longitudinal slots such that movement of the auxiliary pawl through at least one of the longitudinal slots causes deformation of the adjacent longitudinal body portions to urge the knife driver and knife holder into more secure engagement.
12. 12. The surgical stapling device of claim 1, further comprising a bushing secured to the inner housing portion of the outer housing, wherein the auxiliary pawl is supported on the bushing.
13. 13. A reload assembly, comprising: a housing shell comprising an outer shell portion and an inner shell portion, the inner and outer shell portions defining an annular cavity; an auxiliary pawl supported within the housing shell; A staple cartridge secured to the housing shell and supporting a plurality of staples; a staple pusher defining a through-bore, the staple pusher being supported within the annular cavity and being movable from a retracted position to an advanced position to eject the plurality of staples from the staple cartridge; A knife holder supported within the through bore of the staple pusher and defining a central bore that receives the inner housing portion of the outer housing, the knife holder being movable about the inner housing portion between a retracted position and an advanced position, the knife holder defining a pocket that receives the auxiliary pawl when the knife holder is in the retracted position to block movement of the knife holder from the retracted position toward the advanced position, and A knife supported on the knife holder.
14. 14. The reload assembly of claim 13 wherein said tool holder comprises an interior surface defining said central aperture of said tool holder, said interior surface of said tool holder supporting at least one primary pawl, said interior housing portion of said outer housing comprising an exterior surface defining at least one longitudinal groove, said at least one longitudinal groove receiving said at least one primary pawl, said at least one primary pawl having a proximal portion, a distal portion and an abutment surface separating said proximal portion of said at least one longitudinal groove from said distal portion of said at least one longitudinal groove, wherein said at least one primary pawl moves into interference engagement with said abutment surface as said tool holder is moved from its retracted position toward its advanced position.
15. 15. The reload assembly of claim 14, wherein the auxiliary pawl is longitudinally fixed to the outer housing shell.
16. 16. The reload assembly of claim 15, wherein the auxiliary pawl is resilient and comprises a spring clip.
17. 17. The reload assembly of claim 15, wherein the auxiliary pawl is rigid.
18. 18. The reload assembly of claim 13, wherein said tool holder comprises a plurality of resilient longitudinal body portions defining said central aperture, each of said longitudinal body portions being spaced apart from an adjacent longitudinal body portion to define a longitudinal slot.
19. 19. The reload assembly of claim 18, wherein said pocket is defined in an adjacent longitudinal body portion of said tool holder and communicates with a respective one of said longitudinal slots such that said auxiliary pawl is aligned with said respective one of said longitudinal slots, said auxiliary pawl being movable into said respective one of said longitudinal slots upon movement of said tool holder from its retracted position toward its advanced position.
20. 20. The reload assembly of claim 19, wherein the width of the auxiliary pawl is greater than the width of the respective one of the longitudinal slots such that movement of the auxiliary pawl by the respective one of the longitudinal slots causes the adjacent longitudinal body portions to deform outwardly.

Description

Reload assembly with knife holder lock Cross Reference to Related Applications The present application claims the benefit and priority of U.S. provisional patent application No. 62/948,400 filed on 12 months 16 in 2019, the entire disclosure of which is incorporated herein by reference. Technical Field The present disclosure relates to circular stapling devices, and more particularly, to a reload assembly for a circular stapling device having structure to hold a knife holder of the reload assembly in a retracted position after firing the stapling device. Background Conventional circular stapling devices include an elongate body and a housing or reload assembly supported on a distal portion of the elongate body. The reload assembly includes a housing shell, a staple cartridge having a plurality of staples supported on the housing shell, a pusher assembly, a knife defining a cylindrical cavity, and a knife holder supporting the knife. The pusher assembly includes an annular pusher and a staple pushing member engaged with the annular pusher and movable to move the staple pushing member to eject staples from the staple cartridge. The knife holder is movable to advance the knife through the staple cartridge to core or cut tissue. After the stapling device has been operated to staple and cut tissue, the knife holder and knife are retracted to withdraw the knife into the housing shell. This serves two purposes. A first object is to move the knife to a position that allows removal of the tissue annulus from the lumen defined by the knife. A second object is to position the knife in a position recessed within the housing shell to avoid injury to the clinician during handling and positioning of the reload assembly. In some cases, the tissue ring is compressed to a degree within the lumen defined by the knife that makes it difficult to remove the tissue ring from the lumen defined by the knife. In such cases, removal of the tissue annulus has a tendency to pull the knife out of the housing shell. There is a continuing need in the art for a reload assembly that includes an improved structure for holding the knife/blade holder in the retracted position. Disclosure of Invention One aspect of the present disclosure relates to a surgical stapling apparatus that includes an adapter assembly and a reload assembly. The adapter assembly has a proximal end portion and a distal end portion. The reload assembly is supported on the distal end portion of the adapter assembly and includes a housing shell, auxiliary pawls, a staple cartridge, a staple pusher, a knife holder, and a knife. The outer housing includes an outer housing portion and an inner housing portion defining an annular cavity. The auxiliary pawl is supported within the outer housing. The staple cartridge is secured to the housing shell and supports a plurality of staples. The staple pusher defines a throughbore supported within an annular cavity of the housing shell and is movable from a retracted position to an advanced position to eject staples from the staple cartridge. The knife holder is supported within the through bore of the staple pusher, defines a central bore that receives the inner housing portion of the outer housing and is movable about the inner housing portion between a retracted position and an advanced position. The tool holder defines a pocket that receives the auxiliary pawl to block movement of the tool holder from the retracted position toward the advanced position when the tool holder is in the retracted position. The annular knife is supported on the knife rest. Another aspect of the present disclosure is directed to a reload assembly that includes a housing shell, an auxiliary pawl, a staple cartridge, a staple pusher, a knife holder, and an annular knife. The outer housing includes an outer housing portion and an inner housing portion defining an annular cavity. The auxiliary pawl is supported within the outer housing. The staple cartridge is secured to the housing shell and supports a plurality of staples. The staple pusher defines a throughbore supported within the annular cavity and is movable from a retracted position to an advanced position to eject staples from the staple cartridge. The knife holder is supported within the through bore of the staple pusher, defining a central bore that receives the inner housing portion of the outer housing and is movable about the inner housing portion of the outer housing between a retracted position and an advanced position. The tool holder defines a pocket that receives the auxiliary pawl to block movement of the tool holder from the retracted position toward the advanced position when the tool holder is in the retracted position. The knife is supported on the knife holder. In aspects of the present disclosure, a stapling device includes a handle assembly having a proximal end portion and a distal end portion. The proximal end portion of the adapter assembly is supported on the handle assembly. In