An apparatus includes a body assembly, a shaft extending distally from the body assembly, an end effector attached to the shaft, and a cartridge. The end effector includes a jaw and an anvil pivotable relative to the jaw. The cartridge includes a deck, a plurality of staples, a compressible buttress, a peripheral member, and a pinching surface. The deck has an upper surface facing toward the anvil. The staples are located within openings formed through the deck. Each staple has a pair of legs extending above the upper surface of the deck. The buttress is located on the upper surface of the deck. Portions of the legs of the staples are disposed the buttress. The peripheral member extends above the upper surface of the deck, laterally adjacent to the buttress. The pinching surface is located at a height extending above a height of the legs of the plurality of staples.
