Shortly after the ruby laser was introduced, in 1959, a study for the use of this ruby laser for the in-vitro dissolution of arteriosclerotic plaque was performed.' With subsequent advances in laser technology and with refined delivery techniques, laser applications to the treatment of arteriosclerosis in the coronary arteries and peripheral vascular system is a reality. This report reviews the disease process, arteriosclerosis, and the ef-forts towards laser treatment of this disease. We conclude with a review of the technical barriers to the routine application of laser energy in arteriosclerotic cardiovascular disease and the progress being made to overcome these obstacles.

The laser has been used diagnostically and therapeutically in many clinical disciplines. Until recently, cardiac surgery has found little advantage for the use of light energy compared to conventional techniques. Early studies, however, show promise in utilizing the laser as an instrument for increased precision of tissue ablation and for access to areas percutaneously that were previously approached through the open chest.

Direct laser energy delivery was compared to fiber optic laser energy delivery by the performance of open laser endarterectomy in the rabbit arteriosclerosis model. In Group I, 6 open laser endarterectomies were performed with a hand-held CO2 laser (10.6 pm). In Group II, 6 open laser endarterectomies were performed with an argon ion laser (488 nm and 514.5 nm) with the laser beam directed through a 400 μm quartz fiber optic. Gross and light microscopic examination revealed uneven endarterectomy surfaces and frequent perforations at the end points in Group I. In Group II, the endarterectomy surfaces were even and the end points were fused with a tapered transition. Energy density for Group I was 38 ±5 J/cm2. Energy density for Group II was 110±12 J/cm2. CO2 laser energy was better absorbed by arteriosclerotic rabbit aortas than argon ion laser energy, but it could not be as easily controlled. We conclude that a more precise endarterectomy can be performed with fiber optic delivery of laser energy.