Abstract: There is provided an excimer laser catheter which also has at the distal end thereof a tip-deflecting wire, such as a relatively small-size balloon catheter, one which is located alongside and to one side of the laser catheter and is adapted to be used by being activated to cause the laser to be located eccentrically with respect to the lumen of the blood vessel which it has entered and to be directed at adjacently located plaque which the laser would otherwise miss. With equipment of this kind, it is possible to perform in many instances a satisfactory angioplasty essentially with the laser alone, without incurring the delays and the risks and other drawbacks involved in using the conventional adjunctive balloon-catheter angioplasty following laser angioplasty. An ultrasonic transducer and a catheter tip is used to determine the location and morphology of atherosclerotic blockage.