| 摘要 |
<p>A rotatable atherectomy cutter (10) for removing obstructive tissue from a body vessel includes a hollow cylindrical base (12) having an outer wall (46), a hollow cylindrical guide tip (16) coaxially distanced from the base for slidably receiving a guide wire (18) and a pair of diametrically opposed blades (14) each having a distal end and a proximal end. The distal end of each blade is connected to the guide tip and the proximal end connected to the base for alternately cutting the tissue with a first cutting edge (50) and a second cutting edge (52) longer than the first cutting edge. The proximal end of each blade is connected to an ovoid portion (40) formed in the base for allowing the second cutting edge of the blade to extend beyond the outer diameter of the cylindrical base to cut a diameter of tissue larger than the diameter of the base. The base includes a straight wall portion (54) connecting the pair of blades to establish the first cutting edge on each of the blades. The blades are inclined to the longitudinal axis of the cutter at an angle in the range of between thirty (30) and seventy (70) degrees and are preferably made of stainless steel. Also included is a mechanism for removing debris through an opening in the top of the base. The ovoid portion extends the second cutting edge of the blades beyond the outer wall a distance of approximately five (5) to ten (10) percent of the diameter of the base.</p> |
