Laser-induced ablation of atherosclerotic plaque

摘要

A method of ablating atherosclerotic plaque by means of short- duration laser light pulses. A carotenoid, such as beta-carotene, is preferably administered to the patient by injection or ingestion prior to exposing the plaque with laser light. Research data obtained by analysis of the absorption characteristics of plaque and the healthy arterial tissue reveals that the plaque may be selectively ablated without damaging the surrounding normal tissue by illuminating the plaque with laser light having a wavelength of about 430 to about 510 nanometers such that the relative absorption coefficient exhibited by the plaque is more than 1.5 times the absorption coefficient of the arterial tissue. Short duration laser light pulses preferably illuminate the plaque for less than the thermal relaxation time of the volume of exposed material. The intensity of the laser light is preferably in the range from about 1 to about 9 joules/cm.sup.2 in order to ablate the plaque without endangering the surrounding tissue. The carotenoid administered to the patient enhances the absorption coefficient of the plaque to facilitate ablation and additionally facilitates the detection of the plaque.