Various embodiments of devices and systems comprising a polymer driveshaft for use in high-speed rotational medical procedures, e.g., atherectomy, are disclosed. Generally, the primary driveshaft for transferring torque and activating rotation of a tool attached thereto, e.g., an abrasive element, is constructed with at least a polymer outer and inner surface. In certain embodiments, the polymer driveshaft may comprise a metallic band for fixed attachment of a structure, e.g., an abrasive element, thereto. Various embodiments may comprise a coupler that connects a drive shaft connected with a prime mover, e.g., a turbine or electric motor, with the polymer drive shaft, the coupler comprising openings through the coupler wall to the inner diameter of the coupler to allow fluid flow to the inner diameter of the coupled polymer drive shaft.