Using lasers instead of sutures may improve greatly the success of coronary bypass surgery, a San Francisco vascular surgeon predicted.

Dr. John Crew of the San Francisco Heart Institute at Seton Medical Center has used lasers to weld shut wounds in arteries in the arms of more than 15 patients and plans to use the technique in at least 50 patients by year's end.

The bypass procedure provides a new path for blood flow to the heart muscle, rerouting it around arteries clogged with plaque. One problem with current bypass technique, Crew said, is that sutures in the arteries leave scar tissue and the scars can promote thickening of artery walls, closing off the new blood supply pathway.