Mid-infrared Laser Coronary Angioplasty — Experimental Study

Abstract

It is well known that continuous wave lasers such as the Nd-YAG laser operating in the infrared range of wavelength allow the heat generated by the laser to diffuse away from the irradiated area, making it difficult to control ablation depth and extent of thermal necrosis. This extensive thermal injury is a significant limitation to laser application in which great precision is required, such as in the removal of atherosclerotic material from obstructed vessels [1]. Indeed, the major issue in this field is protection of the vessel wall in order to prevent perforation from occurring [2]. Over the past years there has been growing interest in using pulsed infrared lasers to ablate tissue [3, 4]. These lasers emit wavelengths that are strongly absorbed by tissue and have brief pulse durations that limit diffusion of heat from the irradiated site. Thus, they can ablate tissue while leaving only small zones of residual thermal injury. Erbium YAG and pulsed CO2 lasers are suitable for such an application, but they cannot be transmitted through currently available optical fibers, making them unsuitable for endovascular use [5].