Tissue-removing catheter including turbine

A method of removing tissue in a body lumen, the method comprising:

• advancing an elongate body through the body lumen to position a distal end portion of the elongate body adjacent the tissue and a proximal end portion of the elongate body outside of the body lumen;
• using an actuator outside the body lumen to deliver a flow of propellant to a turbine mounted at an intermediate position between the proximal and distal end portions of the elongate body to rotate a tissue-removing element about a longitudinal axis of the elongate body to remove the tissue, whereby an entirety of the turbine is located proximally of the tissue-removing element and a flexible portion of the elongate body extending between the turbine and the rotatable tissue-removing element;
• and
• using the actuator outside the body lumen to control the flow of the propellant to the turbine to control the rotational speed and/or torque of the tissue-removing element.

A tissue-removing catheter for removing tissue in a body lumen, the tissue-removing catheter comprising:

• an elongate body having an axis and proximal and distal end portions spaced apart from one another along the axis, the elongate body being sized and shaped to be received in the body lumen;
• a turbine fixed to the elongate body and disposed at an intermediate position between the proximal and distal end portions of the elongate body, wherein the turbine includes a rotor and a stator, the rotor configured to rotate about a drive axis of the turbine, the drive axis being coaxial with the axis of the elongate body;
• a rotatable tissue-removing element at the distal end portion of the elongate body and operatively coupled to the turbine such that the turbine imparts rotation of the tissue-removing element, the tissue-removing element being configured to remove the tissue from the body lumen as the tissue-removing element is rotated by the turbine;
• a handle mounted to the proximal end portion of the elongate body and operable to deliver a flow of propellant to the turbine to rotate the rotor;
• an exhaust fluidly connected to the turbine and configured to vent the propellant into the atmosphere surrounding the exhaust after at least a portion of the propellant flows through the turbine, wherein the elongate body further includes a return line extending between the turbine and the exhaust and configured to transport the propellant to the exhaust after the propellant flows through the turbine, and wherein the exhaust imparts a vacuum on the turbine to facilitate the movement of the propellant through the turbine;
• and
• an exhaust supply line extending between the handle and a nozzle and configured to divert a portion of the propellant from the turbine and directly into the exhaust, wherein the exhaust constricts the flow of propellant from the exhaust supply line before the flows of the propellant from the return line and exhaust supply line mix to impart the vacuum on the turbine.