Rotational atherectomy device with fluid inflatable support elements and two torque transmitting coils

Abstract

A rotational atherectomy device for removing a stenotic tissue from a vessel of a patient is disclosed. The device comprises a rotatable, flexible, hollow drive shaft having a fluid impermeable wall defining a fluid impermeable lumen of the drive shaft and, an abrasive element mounted to a distal end portion of the drive shaft proximal to and spaced away from a distal support element formed at a distal end of the drive shaft, the distal support element being inflatable by pressurized fluid which flows in an antegrade direction through said lumen of the drive shaft and is at least partially re-directed into the distal fluid inflatable support element. The distal fluid inflatable support element has an outer wall comprising an outflow opening located such that said outflow opening faces an inner surface of a treated vessel during rotation of the drive shaft so that a flow of fluid through said outflow opening forms a layer of fluid between the outer wall of the rotating fluid inflated distal support element and a wall of the treated vessel to form a fluid bearing between the outer wall of the rotating fluid inflated distal support element and the wall of the treated vessel, the drive shaft being comprised of at least one fluid impermeable membrane and at least two torque transmitting coils, one of said coils extending distally beyond the distal end of the other coil and conveying torque to the abrasive element mounted to the drive shaft distal to and spaced away from a portion of the drive shaft formed from the fluid impermeable membrane and said torque transmitting coils.