EARLY CLINICAL TRIALS indicate that future uses of the laser for treating coronary artery occlusions probably will include providing a better channel for the percutaneous transluminal coronary angioplasty (PTCA) balloon and smoothing the contours of the recanalized arterial lumen after the PTCA procedure to reduce the likelihood of reocclusion. But it may be sometime in the 1990s before technological improvements permit the laser to achieve this potential. That is the prediction of Timothy A. Sanborn, MD, associate director, Cardiovascular Research Laboratory, Boston University Hospital. Sanborn and colleagues have performed extensive laser thermal angioplasty studies in animals and have been successful in reopening 50 of 56 femoropopliteal occlusions in humans (JAMA1987;257:288). In 26 of these patients "with initially successful procedures," some of whom have been followed for nearly a year, there have been two reocclusions (Lancet1986;1:1457-1459). This led to their initial use of laser thermal angioplasty in a