A surgical stapler end effector assembly, the end effector assembly comprising: (a) a staple cartridge, wherein the staple cartridge comprises: (i) a plurality of staples, and (ii) a deck, wherein the staple cartridge is operable to drive the staples through the deck; (b) an anvil, wherein the anvil is movable from an open position toward the staple cartridge to reach a closed position, wherein the anvil includes an underside having staple forming surface configured to receive staples driven through the deck; and (c) a buttress assembly, wherein the buttress assembly comprises: (i) a buttress body, and (ii) an adhesive material, wherein the adhesive material is configured to removably secure the buttress body to the deck of the staple cartridge or the underside of the anvil, wherein the adhesive material comprises a polymer, wherein the polymer is bioabsorbable, wherein the polymer is in a flowable state on the buttress body; characterized in that: (i) the deck of the staple cartridge defines a trough, wherein at least some of the flowable polymer is contained in the trough; and/or in that: (ii) the surgical stapler end effector assembly further comprises a retainer, wherein the retainer is configured to releasably hold the buttress assembly, wherein the adhesive material is provided in a plurality of discrete regions, wherein the retainer comprises a plurality of projections configured to engage the buttress body at a plurality of discrete locations associated with the discrete regions to thereby provide focused pressure on the buttress assembly at the discrete regions. (a) a staple cartridge, wherein the staple cartridge comprises: (i) a plurality of staples, and (ii) a deck, wherein the staple cartridge is operable to drive the staples through the deck; (i) a plurality of staples, and (ii) a deck, wherein the staple cartridge is operable to drive the staples through the deck; (b) an anvil, wherein the anvil is movable from an open position toward the staple cartridge to reach a closed position, wherein the anvil includes an underside having staple forming surface configured to receive staples driven through the deck; and (c) a buttress assembly, wherein the buttress assembly comprises: (i) a buttress body, and (ii) an adhesive material, wherein the adhesive material is configured to removably secure the buttress body to the deck of the staple cartridge or the underside of the anvil, wherein the adhesive material comprises a polymer, wherein the polymer is bioabsorbable, wherein the polymer is in a flowable state on the buttress body; (i) a buttress body, and (ii) an adhesive material, wherein the adhesive material is configured to removably secure the buttress body to the deck of the staple cartridge or the underside of the anvil, wherein the adhesive material comprises a polymer, wherein the polymer is bioabsorbable, wherein the polymer is in a flowable state on the buttress body; (i) the deck of the staple cartridge defines a trough, wherein at least some of the flowable polymer is contained in the trough; and/or in that: (ii) the surgical stapler end effector assembly further comprises a retainer, wherein the retainer is configured to releasably hold the buttress assembly, wherein the adhesive material is provided in a plurality of discrete regions, wherein the retainer comprises a plurality of projections configured to engage the buttress body at a plurality of discrete locations associated with the discrete regions to thereby provide focused pressure on the buttress assembly at the discrete regions.