A surgical instrument and method of operating on a tissue includes a shaft assembly and an end effector. The end effector extends in a longitudinal direction from the shaft assembly and has a first jaw, a second jaw, and a deformable hydraulic member. The second jaw is movably mounted relative to the first jaw and is configured to transition between an open configuration and a closed configuration. The first and second jaws are thus configured to have the tissue positioned therebetween in the closed configuration. The deformable hydraulic is configured to contain a fluid. With the fluid contained in the deformable hydraulic member, the deformable hydraulic member is configured to sever the tissue positioned between the first and second jaws in the closed configuration.