Experimental technique of laser coronary endarterectomy and its immediate effects on atherosclerotic plaques in cadaver hearts.

The immediate effects of carbon dioxide laser radiation were assessed in the normal canine aorta, the human atherosclerotic aorta, and 24 human coronary arteries from nine cadaver hearts. The parameters needed for precise control of laser energy were identified. Penetration of a 1-mm thick arterial wall required a minimum power (5 watts), power density (781 watts cm(2)), and radiant energy (1.5 joules). Use of an optimal pulse duration (30 msec or less) resulted in less thermal injury to the adjacent arterial wall. Laser radiation relieved stenosis and reopened totally occluded vessels in 21 of 24 coronary arteries. Coronary stenoses were not relieved in two heavily calcified arteries, and perforation occurred in another artery. In successfully treated arteries, laser coronary endarterectomy increased the luminal diameter from 25 to 100%.