The expandable sheath and methods of use disclosed herein are used to deliver a prosthetic device through a patient's vasculature. The sheath is constructed to be expandable in the circumferential direction, while maintaining sufficient stiffness in the longitudinal direction to withstand pushing and resist kinking. The sheath includes a plurality of curved arms extending outwardly from a longitudinally extending spine. The curved arms move away from the longitudinal axis of the sheath when pushed radially outwardly by a passing prosthetic device, and move back toward the longitudinal axis once the prosthetic device has passed.