A surgical stapling device (10) is disclosed including a tool assembly (16) having an anvil assembly (24) and a cartridge assembly (26). The cartridge assembly (26) includes ridges (46) or protrusions (46) formed along peripheral walls of the cartridge assembly (26) to grip and stabilize tissue clamped between the anvil and cartridge assemblies (24,26). The ridges (46) serve as grippers to prevent the tissue from moving during staple formation in both the lateral and longitudinal directions. Improved staple formation can be achieved by stabilizing the tissue during staple formation.