LASER ANGIOPLASTY USING CARBON MONOXIDE LASERS.

To solve the problem of perforations of the blood vessel by thermal damage to the artery wall during laser angioplasty, laser light that cannot penetrate the artery wall is used. In particular, the combination of carbon monoxide (CO) lasers and chalcogenide glass fibers is used. The penetration depth of CO laser radiation, 5- mu m in wavelength, for living tissue is shallow (100-200 mu m), since water strongly absorbs mid-IR light. Vaporization of a thin thermal necrotic layer is attained by the high-intensity irradiation of the CO laser. The flexible power delivery of the CO laser has been successfully demonstrated.