A distal atherectomy catheter comprises a flexible outer catheter tube housing a reciprocal cutting element at its distal end. The cutting element is connected to an inner catheter tube concentrically located within the outer catheter tube. An annular passage defined between the inner and outer tubes provides a discharge passage communicating with an external vacuum mechanism for collection of excised material removed from the coronary vessel. A flexible drive shaft extending through the inner catheter tube terminates in a detachable cutting burr for boring through obstructions in the coronary vessel. The drive cable is connected to an external drive motor.