Enhanced Laser Ablation of Atherosclerosis using Hematoporphyrin Derivatives

Abstract

For more safe and efficacious laser angioplasty, it is important to ablate the atherosclerotic lesion by as lower energy as possible. This study examined the enhancement of laser ablation in blood by using a photosensitizer.
The laser source is Argon ion laser and Hematoporphyrin Derivatives (HpD) is used as a photosensitizer. Atherosclerotic rabbits, whose atherosclerotic lesion in the aorta were induced by balloon damage and by 2% cholesterol diet, were divided into two groups, that is, HpD (5mg/kg) administration, and non-administration as controls. The laser energy was 100mW-2000mW and the exposure time was 1sec.-180sec. Laser ablation was performed in saline and in blood.
Atherosclerosis lesions using HpD were vaporized by lower energy and shorter time level than controls. It was also recognized that each ablation was enhanced in blood. Using HpD, the laser ablating threshold of atherosclerosis intima was lowered and the ablating volume was increased. Laser ablation without the perforation or the injury of normal wall will be accomplished by this method.