Laser ablation parameters of atherosclerotic arteries

Summary The threshold of atherosclerotic plaque ablation in water by the XeCl laser radiation was measured to be of (1.5±0.2) J/cm². Within the simple thermal model this value corresponds to the mean temperature of about 373 K in the irradiated volume as for other angioplasty lasers. Time-of-flight probing of ablation in air by the XeCl and CO₂ lasers revealed microsecond lifetimes of ablated volumes that confirm the mechanism of explosive boiling of superheated tissue water. So the local temperature must be about 582 K which can be due to inhomogeneous light distribution and absorption. The short lifetime leads to the absence of heat diffusion and, hence, to the ablative character of tissue destruction.