The effect of irradiation condition on CO laser ablation

Abstract

The appropriate contact irradiation condition for CO laser angioplasty with a thin As-S glass fiber was studied. An ablation depth and coagulation thickness in atheromatous human aorta were investigated by changing duty ratio, frequency, and contact pressure. The fiber cable which is able to use clinically was composed of 200μm in diameter As-S fiber and 400μm in diameter CaF₂ contact chip. The power at the end of the fiber was adjusted to be 2W having sufficient safety margin. The higher contact pressure gave the better ablation efficiency. At the constant contact pressure 1kg/cm2 the best result for fine ablation with thin thermal damaged layer was obtained by the duty ratio of 20%and frequency of 1Hz.