Excimer Laser Coronary Atherectomy

Abstract

Excimer laser coronary atherectomy (ELCA) was introduced in the 1980s for treatment of coronary artery disease, but use was restricted because the ELCA laser was activated with contrast medium still present in the coronary arteries, resulting in unacceptably high rates of dissection and perforation. Lasing in contrast medium leads to intense vapor bubble expansion and implosion, causing forceful dilation and invagination of the adjacent arterial wall after each excimer laser pulse, which can cause dissection and perforation. When the saline flush technique was applied in the 2000s, the use of ELCA spread because of the reduced rate of complications compared with the earlier attempts. In addition, the introduction of a smaller profile 0.9 mm ELCA catheter allowed treatment of a wider spectrum of coronary artery lesions, such as tortuous lesions, chronic total occlusions (CTOs), and balloon-uncrossable lesions. Unlike plain old balloon angioplasty and stenting, ELCA has three unique mechanisms of action: photoablation, photothermal, and photomechanical. Through these mechanisms of action, ELCA vaporizes plaque in complex coronary anatomies containing thrombus, soft atheroma, fibrous tissue, and calcium. In addition, laser energy is capable of suppressing platelet aggregation as a pleiotropic effect. The current clinical indications for ELCA are saphenous vein grafts, acute coronary syndrome, in-stent restenosis, bifurcation lesions, ostial lesions, moderately calcified lesions, CTOs, balloon-uncrossable lesions, and stent underexpanded lesions.