Surgical anastomosis stapling instrument

A surgical stapling instrument for joining a pair of hollow organ sections with a plurality of surgical staples around a hollow lumen between the organ sections, comprising:

• a stapling head assembly including a staple holder containing a plurality of surgical staples, an anvil for forming the staples, said anvil being mounted on an anvil shaft slidably supported for movement relative to said stapling head assembly to allow the tissue of the organ sections to be clamped between said anvil and said staple holder, and a staple driver for engaging and driving the staples from said staple holder into the tissue and against said anvil;
• an actuator handle assembly remote from said stapling head assembly and having first actuator means for controlling the motion of said anvil and second actuator means for controlling the motion of said satle driver;
• a shaft assembly including a longitudinally curved tubular supprot shaft for mounting said stapling head assembly on said actuator handle assembly;
• a tension member contained within said tubular support shaft for transmitting longitudinal tension and longitudinal motion relative to said support shaft form said first actautor means to said anvil shaft to move said anvil toward said staple holder to clamp the tissue and resist the forces exerted on said anvil when the staples are driven through the tissue and formed against said anvil;
• a compresson member contained within said tubular supoprt shaft for transmitting longitudinal compressive force and longitudinal motion relative to said support shaft from said second actuator means to said staple driver to advance said staple driver to drive the staples from said staple holder into the tissue and against said anvil;
• and
• said compression member having an elongated wall section extending through said tubular support shaft and including an integral guide surface thereon for engaging and supporting a flexible band;
• a trocar secured to said tension member and slideably received in said stapling head assembly for longitudinal movement relative to said staple holder;
• and
• retainer means for detachably securing said trocar to said anvil shaft;
• wherein said trocar contains a distal end and a proximal end which includes an enlarged trocar tip and a circumferential lip, such that said circumferential lip is chamfered proximally of said circumferential lip to facilitate movement of tissue along said trocar;
• and
• said anvil shaft comprises a hollow sleeve for engaging said trocar.