Transmyocardial laser revascularization (TMR)

Transmyocardial laser revascularization (TMR) uses a laser beam to improve blood flow to heart muscle. TMR is typically performed along with coronary artery bypass graft (CABG or bypass) surgery. But TMR is not commonly used.

In this technique, a laser beam is used to create tiny channels in the wall of the heart. The initial concept of TMR was that blood supply would flow through these channels and supply oxygen to the heart muscle. The mechanism by which TMR works is not well understood. TMR appears to reduce angina and improve exercise tolerance and quality of life.¹ Some studies suggest that it improves blood flow to the heart muscle, while other studies do not. Some investigators believe that the channels seal off, but that new blood vessels then grow in around the scar, improving blood flow. Others believe that TMR works by reducing the number of nerve fibers that conduct the pain of angina.

This treatment is neither widely available nor appropriate for everyone. It is best suited for people who have blocked arteries that cannot be treated using bypass surgery or angioplasty. Or it may be performed at the same time as bypass surgery to reach areas of the heart that are not good for bypass grafting.

Citations

1. Burkhoff D, et al. (1999). Transmyocardial laser revascularisation compared with continued medical therapy for treatment of refractory angina pectoris: A prospective randomised trial. Lancet, 354(9182): 885–890.