ST. LOUIS PARK, Minn. (AP) _ Doctors say they have used a new laser device to open a clogged human blood vessel.

The successful procedure at Methodist Hospital on Tuesday was described Wednesday by Dr. Leonard Nordstrom, the heart specialist who performed it on the leg of 54-year-old computer programmer Robert Retzlaff.

Retzlaff, of Corcoran, was walking the corridors of the hospital Wednesday afternoon, saying he was ready to go home.

''I feel great,'' he said.

The device, called a laser-enhanced angioplasty system, was developed by GV Medical Inc. of Plymouth at a cost of about $8 million, according to James Grabek, president and chief executive officer of the company.

Doctors previously have used other laser devices to open clogged blood vessels.

GV Medical, which had tested the device on rabbits, received permission from the federal Food and Drug Administration to try it on up to 10 patients with circulation problems in their legs, a problem that is not life- threatening and that usually is treated with drugs or balloon angioplasty.

The greatest potential for the device, if it proves safe and effective, would be on clogged coronary arteries, which are diagnosed in an estimated 100,000 coronary bypass operations each year. That application could be years away, however, because the device is only in initial testing stages.

Retzlaff had severe cramps in his right calf because of a blockage just above the knee. Nordstrom said he tried to enlarge the blocked area with balloon treatment in November, but the artery remained open for less than two months.

He said 20 to 50 percent of arteries opened with balloon angioplasty close within six months, and that he hopes the laser, in combination with the balloon, will improve those figures.