The University of Utah Health Sciences Center is one of 10 U.S. hospitals performing final clinical trials of a new device in the treatment of arteriosclerosis.

The device, called the PLAC laser angioplasty system, is being used to treat patients suffering from clogged arteries of the leg. Doctors expect that treatment with the device will relieve leg pain and, in severe cases of the disease, provide an alternative to amputation.The federal Food and Drug Administration gave approval in late January to PLAC Inc., and HGM Medical Laser Systems Inc. of Salt Lake City to begin a final set of clinical studies. Initial testing of the device at Phoenix Humana Hospital was completed successfully in late 1988.

Rick Strickland, company spokesman, said the PLAC system consists of a high-energy laser and special platinum-tipped catheters. During surgery, a PLAC catheter is introduced into an artery and advanced to the obstructed area. The tip of the catheter is then heated very quickly with laser energy, destroying plaque near the catheter tip. The process continues until the artery is cleared and normal blood flow is restored.

Vascular specialists at PLAC Inc. say the device is unique because the temperature at the tip of the catheter is precisely controlled during surgery. This feature virtually eliminates the possibility of causing excessive thermal damage to artery walls, a common problem with "hot-tip" angioplasty devices.

The 10 hospitals involved in the study will treat 250 patients. PLAC Inc. and HGM anticipate that the treatment will be available to the general public later this year.