Koro Yotsuya

Laser Angioplasty With Excimer Laser :Animal Experiment

Excimer laser is able to destruct tissue with less thermal effect. This characteristics was considered to prevent thermal perforation in laser angioplasty. In order to realize coronary laser angioplasty with excimer laser under the visual condition, the basic studies were performed to evaluate the tissue reactions of excimer laser on atheroma and to develop laser endoscopic system for the coronary arteries. The tissue reactions of excimer laser in atheroma were evaluated with rabbits atherosclerotic aorta, which was made with 1.5% high cholesterol diet. The bigger tissue destruction was obtained in accordance with the increase of the oscillating frequency. Excimer laser indused rather selective destruction of atheroma with high oscillating frequency. The fiber transmission of excimer laser was tried and atheroma was destructed through 400 μm core diameter fiber. Atheroma was observed as like as small lump under endoscopic obsevation, and excimer laser could be irradiated through the fiber under endoscopic view. In order to realize endoscopic application of excimer laser to the coronary arteries, the endoscope was designed from the point of percutaneous approach method to the coronary arteries, and 1.5 mm diameter of endoscope with the channel for laser fiber was developed experimentally. The endoscope could be inserted deeply into the coronary arteries of goat, and the laser irradiation could be performed under endoscopic observation. The possibility of visual coronary laser angioplasty with the combination of excimer laser and coronary endoscope was demonstrated with the endoscope.