#$%^&*AU2019204005A120200116.pdf#####SURGICAL STAPLING APPARATUS WITH ANVIL BUTTRESS ABSTRACT A circular stapling apparatus (10) includes a buttress (328) and an anvil head assembly (324). The anvil head assembly (324) includes an anvil head (326) and an anvil cap (330) secured to the anvil head (326). The anvil cap (330) is positioned to selectively secure the buttress (328) to the anvil head (326). The anvil cap (330) is flexible and includes an outer ring (332) that is selectively movable relative to the anvil head (326) to release the buttress (328) from the anvil head (326).