Stapling device with cut ring biasing member
A circular stapling device includes a shell assembly and an anvil assembly. The shell assembly includes a housing, a staple cartridge supported on the housing, an annular knife supported within the housing, and a biasing member supported within the housing. The anvil assembly includes a center rod and an anvil head that supports a cut ring that is axially aligned with the annular knife. The biasing member is positioned within the housing and extends to a position distally of the annular knife when the annular knife is in the retracted position to shield the annular knife. The anvil assembly is movably supported in relation to the shell assembly between an unapproximated position and an approximated position, wherein in the approximated position, the biasing member is engaged with the cut ring and urges the cut ring in a distal direction.
1. A circular stapling device comprising:
an elongate body having a proximal portion and a distal portion;
a shell assembly including a housing, a staple cartridge supported on the housing, an annular knife supported within the housing, and a biasing member supported within the housing, the biasing member having a proximal portion and a distal portion, the annular knife being movable within the housing from a retracted position to an advanced position and extending from the distal portion of the housing in the advanced position, the biasing member extending to a position distally of the annular knife when the annular knife is in the retracted position; and
an anvil assembly including a center rod and an anvil head, the anvil head supporting a cut ring that is axially aligned with the annular knife, the anvil assembly being movably supported in relation to the shell assembly between an unapproximated position and an approximated position;
wherein in the approximated position, the biasing member is engaged with the cut ring and urges the cut ring in a distal direction.
2. The circular stapling device of claim 1 , wherein the biasing member is a coil spring.
3. The circular stapling device of claim 2 , wherein the shell assembly includes a pusher assembly, the pusher assembly including a pusher having a plurality of fingers, that is movable from a retracted position to an advanced position to eject staples from the staple cartridge.
4. The circular stapling device of claim 3 , wherein the shell assembly includes a knife carrier that supports the annular knife, the knife carrier being movable from a retracted position to an advanced position within the housing independently of the pusher.
5. The circular stapling device of claim 4 , wherein the housing defines an annular channel, the pusher and the knife carrier being movably supported within the annular channel.
6. The circular stapling device of claim 2 , wherein the shall assembly includes a knife carrier that supports the annular knife, the knife carrier being movable from a retracted position to an advanced position within the housing, the annular knife engaging the cut ring when the anvil assembly and the shell assembly are in the approximated position and the annular knife is in the advanced position.
7. The circular stapling device of claim 6 , wherein the biasing member is secured to the knife carrier.
8. The circular stapling device of claim 7 , wherein the knife carrier defines a retaining groove, the retaining groove receiving a coil of the coil spring to secure the biasing member to the knife carrier.
9. The circular stapling device of claim 2 , wherein the biasing member is positioned within the annular knife.
10. The circular stapling device of claim 1 , wherein the annular knife includes a cutting edge that is positioned distally of the biasing member when the annular knife is in the advanced position.
11. The circular stapling device of claim 1 , further including a handle assembly, the elongate body extending distally from the handle assembly.
12. A shell assembly comprising:
a housing having a proximal portion and a distal portion and defining an annular channel;
a staple cartridge supported on the housing, the shell assembly defining a plurality of staple receiving pockets, each of the staple receiving pockets having a staple;
an annular knife supported within the housing, the annular knife being movable within the housing from a retracted position to an advanced position, the annular knife extending from the distal portion of the housing when the annular knife is in the advanced position; and
a biasing member supported within the annular channel of the housing, the biasing member extending to a position distally of the annular knife when the annular knife is in the retracted position.
13. The shell assembly of claim 12 , wherein the biasing member is a coil spring.
14. The shell assembly of claim 13 , wherein the coil spring is positioned within the annular knife.
15. The shell assembly of claim 14 , wherein the shell assembly includes a pusher assembly, the pusher assembly including a pusher having a plurality of fingers that is movable from a retracted position to an advanced position to eject staples from the staple cartridge.
16. The shell assembly of claim 15 , wherein the shell assembly includes a knife carrier that supports the annular knife, the knife carrier being movable from a retracted position to an advanced position within the housing.
17. The shell assembly of claim 16 , wherein the cutting edge of the annular knife is positioned distally of the biasing member when the annular knife is in the advanced position.
18. The shell assembly of claim 16 , wherein the biasing member is secured to the knife carrier.
19. The shell assembly of claim 18 , wherein the knife carrier defines a retaining groove, the retaining groove receiving a coil of the coil spring to secure the biasing member to the knife carrier.