The end-to-end anastomosis apparatus is provided with a mounting means which can receive a trocar for making holes in tissue and, subsequently, an anvil shaft for the mounting of an anvil assembly for stapling purposes. The anvil shaft is provided with splines which cooperate with splines on a shell liner within the housing of the apparatus to align the buckets on the anvil assembly with the staples in a cartridge secured in the apparatus. In addition, the anvil assembly is provided with a spring for locking of the anvil housing on the anvil shaft.