Multiple part anvil assemblies for circular surgical stapling devices

A circular stapling instrument, comprising:

• a stapling head supporting a plurality of surgical staples therein;
• a firing system operably communicating with said stapling head for applying a firing motion to the stapling head to thereby drive said surgical staples therefrom;
• an anvil adjustment system;
• and
• an anvil assembly comprising:
• an anvil shaft configured to be attached to said anvil adjustment system in a predetermined orientation;
• an anvil support member operably coupled to said anvil shaft and configured
• to be selectively moved between a radially collapsed position and a radially expanded position;
• an anvil plate assembly having a staple-forming surface thereon;
• and
• means for coupling said anvil support member to said anvil plate assembly when said anvil support member is in said radially expanded position such that when said anvil shaft is coupled to said anvil adjustment system in said predetermined orientation, said staple-forming surface of said anvil plate assembly is radially aligned with corresponding said surgical staples in said stapling head.

A method for stapling tissue comprising:

• providing a circular stapling instrument comprising:
• a stapling head supporting a plurality of surgical staples therein;
• a firing system operably communicating with the stapling head for applying a firing motion to the stapling head to thereby drive the surgical staples therefrom;
• and
• an anvil adjustment system;
• providing an anvil support member that is selectively movable between a radially collapsed orientation and a radially expanded orientation;
• providing an anvil plate assembly having a staple forming surface thereon;
• coupling the anvil support member to the anvil adjustment system when the anvil adjustment system is in the radially collapsed orientation;
• inserting the stapling head an attached collapsed anvil adjustment system through an opening in a patient;
• inserting the anvil plate assembly through the opening or another opening in the patient;
• orienting the anvil support member in the radially expanded orientation;
• attaching the anvil plate assembly to the expanded anvil support member in such a way that the staple-forming surface thereon is radially aligned with the surgical staples in the stapling head and that the tissue to be stapled is positioned between the staple forming surface and the stapling head;
• and
• activating the firing system to drive the surgical staples into forming contact with the staple forming surface.