An anvil assembly comprising: an anvil center rod, a head assembly pivotally secured to the anvil center rod assembly by a pivotal connection, the anvil head assembly being pivotable from an operative position to a tilted position, the head assembly including a housing and a post extending proximally from the housing, and a sleeve including a sleeve body (90) disposed about the anvil center rod, characterized in that the post includes a tab, and the sleeve defines an opening for receiving the tab, wherein the tab is received within the opening when the head assembly is in the operative position to lock the sleeve relative to the anvil center rod, and movement of the head assembly to the tilted position releases the tab from the opening to permit movement of the sleeve relative to the anvil center rod. The sleeve body (90) optionally includes annular lips (90a, 90b) formed on proximal and distal ends, respectively. They are configured to maintain an anastomosis donut and about the sleeve body (90) when the sleeve body (90) is moved proximally.
