Patent ID: 8388637

Claim:
A rotational atherectomy device for removing a stenotic lesion from within a vessel of a patient, the device comprising: a rotatable, flexible drive shaft including a torque transmitting coil and and a fluid transport lumen extending therethrough, the torque transmitting coil and the fluid transport lumen being coaxial along a longitudinal axis; an eccentric abrasive element mounted on a region of the drive shaft proximal to and spaced away from its distal end, wherein the abrasive element is mounted in a fixed position relative to the drive shaft and has a center of mass offset from the longitudinal axis in a first direction; and two fluid inflatable counterweights fixed to the drive shaft so as to rotate together with the abrasive element and the drive shaft, each of the two fluid inflatable counterweights being at least partially defined by a flexible, fluid impermeable membrane and having a center of mass offset from the longitudinal axis in a second direction that is opposite from the first direction, the inflatable counterweights comprising: a distal fluid inflatable counterweight located at a distal end of the drive shaft and spaced away from the abrasive element and, a proximal fluid inflatable counterweight located on the drive shaft proximal to and spaced away from the abrasive element, wherein a distal end of the fluid transport lumen of the drive shaft is continuously closed by a fluid impermeable wall that crosses the longitudinal axis such that fluid is prevented from exiting the fluid transport lumen in a longitudinal direction of the longitudinal axis when fluid is moved through the fluid transport lumen.