Stapler cartridge with an integral knife
Stapler cartridges and surgical apparatus that include a stapler cartridge can include a knife that retracts into the stapler cartridge after cutting stapled tissue to prevent an operator being cut by the knife during replacement of the used stapler cartridge with a new stapler cartridge. A stapler cartridge includes a staple pushing shuttle, a knife member slidably coupled with the staple pushing shuttle, and a cartridge body. The staple pushing shuttle is slidably coupled to the cartridge body. The cartridge body includes a guide track engaged by the knife member and configured so that a cutting blade of the knife member protrudes from the cartridge body during a first portion of a distal movement of the staple pushing shuttle and the cutting blade is retracted into the cartridge body during a second portion of the distal movement of the staple pushing shuttle.
1. A stapler cartridge comprising:
a cartridge body comprising a proximal end, a distal end, an upper surface, staple openings, a longitudinal slot exposed at the upper surface, and a guide track;
staples, wherein each of the staples is disposed in a respective one of the staple openings;
a staple pushing shuttle slidingly disposed with the cartridge body and comprising ramp portions, a guide portion, and a knife slot that extends through the guide portion, wherein the ramp portions are configured to deploy staples during a distal movement of the staple pushing shuttle, and wherein the knife slot is aligned with the longitudinal slot; and
a knife member slidingly disposed in and extending through the knife slot when the knife member is in a deployed position relative to the guide portion, wherein the knife member comprises a cutting blade and a guide track engagement feature that protrudes transversely relative to the longitudinal slot and is engaged with the guide track,
wherein the guide track is configured to position the knife member within the knife slot during a first portion of the distal movement of the staple pushing shuttle so that the cutting blade protrudes above the upper surface and reposition the knife member within the knife slot during a second portion of the distal movement of the staple pushing shuttle to retract the cutting blade below the upper surface and at least partially into the knife slot.
2. The stapler cartridge of claim 1 , wherein:
the guide portion has a bearing surface shaped to interface with a complementarily shaped surface of the cartridge body to guide longitudinal translation of the staple pushing shuttle relative to the cartridge body.
3. The stapler cartridge of claim 2 , wherein the guide portion has a cylindrical outer surface that comprises the bearing surface.
4. The stapler cartridge of claim 2 , wherein:
the guide portion extends from a vertical rib member of the staple pushing shuttle; and
the vertical rib member forms a central portion of the staple pushing shuttle.
5. The stapler cartridge of claim 4 , wherein the vertical rib member provides an interface for the knife member that is perpendicular to the upper surface.
6. The stapler cartridge of claim 5 , wherein:
the cartridge body comprises a second guide track;
the knife member comprises a second guide track engagement feature engaged with the second guide track,
wherein the second guide track is configured to position the knife member within the knife slot during the first portion of the distal movement of the staple pushing shuttle so that the cutting blade protrudes above the upper surface and reposition the knife member within the knife slot during the second portion of the distal movement of the staple pushing shuttle to retract the cutting blade below the upper surface and at least partially into the knife slot.
7. The stapler cartridge of claim 6 , wherein each of the guide track engagement feature and the second guide track engagement feature protrude distally to interface with a vertical rib of the staple pushing shuttle to stabilize a position and/or an orientation of the knife member relative to the staple pushing shuttle.
8. The stapler cartridge of claim 7 , wherein each of the guide track engagement feature and the second guide track engagement feature slidingly interfaces with the vertical rib.
9. The stapler cartridge of claim 1 , wherein the cartridge body comprises a retaining feature that retains the staple pushing shuttle at the distal end of the cartridge body.
10. The stapler cartridge of claim 9 , wherein the retaining feature comprises a flexible tab that engages the staple pushing shuttle to retain the staple pushing shuttle at the distal end of the cartridge body.
11. The stapler cartridge of claim 1 , wherein:
the cartridge body comprises an attachment feature disposed proximate to the proximal end; and
the attachment feature is configured to removably couple with an end effector that includes an upper jaw.
12. The stapler cartridge of claim 11 , wherein the cartridge body forms a lower jaw of the end effector.
13. The stapler cartridge of claim 1 , wherein the knife slot is configured to constrain the knife member to translation perpendicular to the upper surface of the cartridge body.