A surgical instrument includes a stapling head assembly and a first locking feature. The stapling head assembly has a cartridge housing, a staple deck, a plurality of staples, a staple driver, a cylindraceous knife, and a trocar. The cartridge housing extends along a longitudinal axis that is configured to removably couple with a portion of a shaft assembly. The staple driver is configured to translate distally from a proximal driver position toward a distal driver position to thereby drive each of the plurality of staples distally from an annular array of staple pockets, respectively, for forming the plurality of staples in a tissue of a patient. The first locking feature is operatively connected to the cartridge housing and configured to removably couple against the portion of the shaft assembly for selectively coupling and decoupling the stapling head assembly relative to the portion of the shaft assembly.
