An intravascular catheter includes a flexible guide wire mounted for relative rotational and reciprocal movements within a reciprocal and flexible first tube. A rotary and flexible second tube is mounted on the first tube to define an annular passage therebetween and has a rotary inner cutting head secured on a distal end thereof. The inner cutting head is closely fitted within an outer cutting head that is secured on the first tube. The cutting heads are adapted to cut a blockage in a blood vessel into fragments in response to rotation of the second tube and inner cutting head. The fragments are flushed-out from the inner cutting head and are conveyed away from the cutting heads and through the annular passage by facing spiral threads defined on the first and second tubes.