A self contained gas powered endoscopic surgical apparatus is provided for placing lateral lines of surgical fasteners into body tissue. The apparatus includes a frame portion, an elongated portion extending from the frame portion, and an articulating cartridge assembly mounted to a distal end of the elongated portion. An anvil member is operatively associated with the articulating cartridge assembly and has a forming surface, thereon against which surgical fasteners are driven as they are ejected from the cartridge assembly. A collar which is provided in the elongated portion translates longitudinally to draw a cable which operates to move the anvil member relative to the cartridge assembly, thereby clamping body tissue to be fastened. A self contained pneumatic system is associated with the frame portion and is actuable to eject the surgical fasteners from the cartridge assembly. A linkage mechanism is also provided for effectuating the articulation of the cartridge assembly to increase the range of operability of the apparatus.