Percutaneous material removal device and method

摘要

A catheter-based material removal device includes an elongated tube having a distal material removal tip thereon. The material removal tip includes a one- or two-piece housing affixed to the tube, and a rotating member therein. The rotating member includes a screw thread for coarsely chopping material received within the housing and an outwardly projecting flange for finely chopping the material. The housing includes at least one shearing member located axially adjacent the outwardly projecting flange. The shearing member has a relatively small circumferential size and a shearing edge that removes any material buildup on the axially-facing surface of the flange. Two shearing members may be provided, one each on both the proximal and distal sides of the flange. There may be three flanges restrained within a groove formed with the housing. The shearing members are located adjacent to the groove and may have the shape of teeth, with arcuate inner faces spanning an included angle through the center of the housing of about 25 degrees. The shearing member on the housing extends inward from a lumen wall and the shearing edge thereon has a radially oriented portion and a curvilinear portion blending into tangency with the lumen wall.