A surgical instrument includes a body assembly, a shaft assembly, and an end effector. The end effector has first and second jaws that are configured to receive a tissue therebetween. The end effector also includes a staple cartridge including a plurality of staples and a hydraulic expandable member that is configured to receive a fluid and thereby expand from a contracted state to an expanded state. The hydraulic expandable member is further configured to direct at least one of the plurality of staples toward an anvil of the first jaw for forcing the at least one of the staples against the anvil and forming the at least one of the staples within the tissue.