A surgical stapling apparatus, comprising: a housing, a handle supported by the housing, an elongated body extending distally from the housing, a tool assembly supported at the distal end of the elongated body and having a cartridge assembly (18, 218, 318, 1200) configured and adapted to releasably support a staple cartridge (82, 282, 382 1220) having a plurality of surgical fasteners (84, 1224) therein, and an anvil assembly (20, 220, 320, 420, 1300) having an anvil plate (70, 270, 370, 470, 1370) and, wherein each of the anvil plate (70, 270, 370, 470, 1370) and the staple cartridge (82, 282, 382 1220) define an elongate longitudinal slot (70b, 82c, 270b, 282c, 370b, 382c, 470b, 1234, 1314), a surgical buttress (B, B1, B2) releasably secured to a tissue contacting surface of at least one of the anvil plate (70, 270, 370, 470, 1370) and the staple cartridge (82, 282, 382 1220), wherein each surgical buttress (B, B1, B2) is secured to the at least one of the anvil assembly (20, 220, 320, 420, 1300) and the cartridge assembly (18, 218, 318, 1200) by a proximal anchor and a distal anchor, and a drive assembly (50, 1150) slidably supported in the tool assembly, the drive assembly (50, 1150) including a knife blade (66, 1156) slidably disposed within each elongate longitudinal slot (70b, 82c, 270b, 282c, 370b, 382c, 470b, 1234, 1314), characterised in that the surgical stapling apparatus further comprises a release knife (74, 94, 194, 274, 294, 374, 394, 474, 1240, 1330) supported in at least one of the anvil assembly (20, 220, 320, 420, 1300) and the cartridge assembly (18, 218, 318, 1200) at location adjacent the distal anchor, wherein movement of the drive assembly (50, 1150) from a proximal position to a distal position results in the knife blade (66, 1156) thereof cutting the proximal anchor and in the drive assembly (50, 1150) engaging the release knife (74, 94, 194, 274, 294, 374, 394, 474, 1240, 1330) to cause the distal anchor to be cut by the release knife (74, 94, 194, 274, 294, 374, 394, 474, 1240, 1330), thereby freeing the surgical buttress (B, B1, B2) from the respective at least one of the anvil assembly (20, 220, 320, 420, 1300) and cartridge assembly (18, 218, 318, 1200). a housing, a handle supported by the housing, an elongated body extending distally from the housing, a tool assembly supported at the distal end of the elongated body and having a cartridge assembly (18, 218, 318, 1200) configured and adapted to releasably support a staple cartridge (82, 282, 382 1220) having a plurality of surgical fasteners (84, 1224) therein, and an anvil assembly (20, 220, 320, 420, 1300) having an anvil plate (70, 270, 370, 470, 1370) and, wherein each of the anvil plate (70, 270, 370, 470, 1370) and the staple cartridge (82, 282, 382 1220) define an elongate longitudinal slot (70b, 82c, 270b, 282c, 370b, 382c, 470b, 1234, 1314), a surgical buttress (B, B1, B2) releasably secured to a tissue contacting surface of at least one of the anvil plate (70, 270, 370, 470, 1370) and the staple cartridge (82, 282, 382 1220), wherein each surgical buttress (B, B1, B2) is secured to the at least one of the anvil assembly (20, 220, 320, 420, 1300) and the cartridge assembly (18, 218, 318, 1200) by a proximal anchor and a distal anchor, and a drive assembly (50, 1150) slidably supported in the tool assembly, the drive assembly (50, 1150) including a knife blade (66, 1156) slidably disposed within each elongate longitudinal slot (70b, 82c, 270b, 282c, 370b, 382c, 470b, 1234, 1314),