血管内視鏡下でのExcimer Laser Angioplastyの基礎実験

An excimer laser, which ablates vascular tissue precisely without thermal injury, is expected for the application to the coronary laser angioplasty. In this study, we used a 400μm quartz fiber to transmit a wavelength of 308 nm from a XeCl excimer laser with a pulse duration of 20 nsec. The excimer laser angioplasty was then performed with angioscope for 4 totally occluded femoral arteries of 4 canine models. As a result, we experienced successful recanalization in all arteries using 2.5-6mJ/pulse, 20-30Hz and 6000 shots cumulative exposures. Histological examination of all recanalized arteries revealed favorable results of clear neolumens with no signs of thermal injury. However, perforations were observed in 2 of 4 arteries. Therefore, further investigation are necesarry about several problems, such as operation of the opitical fiber, angioscope, guidance system and transmission of a laser energy through the optical fiber, before a clinical use in the future.