1. Technical Field
The present disclosure relates to a surgical stapling apparatus. More particularly, the present disclosure relates to an endoscopic surgical stapling apparatus that includes a mechanism for articulating a tool assembly.
2. Background of Related Art
Surgical fastening devices, such as surgical stapling apparatuses, are well known in the art. These devices typically include two elongated jaw members to capture or clamp tissue. One jaw member carries a staple cartridge that houses a plurality of staples arranged in at least two lateral rows while the other jaw member has an anvil that defines a surface for forming the staple legs as the staples are driven from the staple cartridge. For the most part, the stapling operation is effected by cam members that travel longitudinally through the staples cartridge, with the cam members actuating upon staple pushers to sequentially eject the staples from the staple cartridge. A knife may travel between the staple rows to longitudinally cut or open the stapled tissue between the rows of staples. Examples of this kind of instrument are disclosed in U.S. Pat. Nos. 3,079,606 and 3,490,675.
U.S. Pat. No. 3,499,591 also discloses a stapling apparatus with a pair row of staples on each side of the incision. The patent discloses a surgical stapler that has an upper jaw member and a lower jaw member. The upper jaw member includes a disposable cartridge while the lower jaw member contains a disposable anvil having a series of staple-closing depressions aligned with a plurality of staple-carrying grooves of the cartridge. In operation, a cam member translates through an elongated guide path between the two sets of staple-carrying grooves. Staple drive members are located within the grooves and are positioned in such a manner so as to effect ejection of the staples from the staple cartridge. Other examples of such stapling instruments are disclosed in U.S. Pat. Nos. 4,429,695 and 5,065,929.
Each of the instruments described hereinabove is designed for use in conventional surgical procedures wherein surgeons have direct manual access to the operative site. Endoscopic or laparoscopic procedures, however, are performed through a small incision or through a narrow cannula inserted through a small entrance wounds in the skin. To address the specific needs of endoscopic or laparoscopic surgical procedures, surgical stapling devices have been developed and are disclosed in, for example, U.S. Pat. Nos. 5,040,715; 5,312,023; 5,318,221; 5,326,013; 5,332,142; and 6,241,139.
Tyco Healthcare Group, LP, the assignee of the present application, has successfully manufactured and marketed endoscopic stapling instruments, such as the Multifire ENDO GIA™ 30, Multifire ENDO GIA™ 60 and Multifire ENDO TA™ 30 instruments, for a number of years. An articulating endoscopic stapler known as the ENDO GIA™ Universal stapler has also been marketed. Typically, these devices include an articulation mechanism having an articulation lever operatively engaged with a cam member having a stepped camming channel. Current stapling instruments allow manual operation of the articulation lever. These instruments have provided significant clinical benefits. Nonetheless, improvements to these instruments are still possible.
It would be desirable to provide an improved articulation mechanism for a surgical stapling apparatus. It would also be desirable to provide an articulation mechanism capable of being operated either manually or electromechanically.
Accordingly, it is an object of this disclosure to provide an improved articulation mechanism that articulates the tool assembly of a surgical stapling apparatus by electromechanical means. It also the object of this disclosure to provide an improved articulation mechanism that will allow a user to articulate with minimal effort and with only one hand the tool assembly of a surgical stapling instrument.
Another object of the disclosure is to provide an articulation mechanism capable of very accurate and fine position adjustment at a speed that can be easily controlled by a variable speed switch.
Still another object of the disclosure is to provide an articulation mechanism with a manual override for additional reliability and safety.