Transmyocardial laser revascularization. Does it have a role in the treatment of ischemic heart disease?

Transmyocardial laser revascularization, with or without coronary artery bypass grafting, is an alternative modality for complete revascularization in selected patients with coronary artery disease. Arguably, this modality works by shunting left ventricular blood directly into the ischemic myocardium via laser-mediated transmural channels. In clinical trials, drilling of laser channels has been strongly correlated with long-term improvement of angina, but a causal relationship has not yet been documented. For now, the usefulness of transmyocardial laser revascularization and the nature of its mechanism remain controversial. Some researchers question the existence of myocardial sinusoids altogether. Others question the physiologic possibility of moving blood from the left ventricular cavity into the myocardium against a pressure gradient. Further questions concern the possible routes through which the additional blood gains access to the myocardium; the difficulty of objectively documenting improved myocardial perfusion after transmyocardial laser revascularization; and the nature of the mechanism responsible for the observed clinical benefit. This article examines the different aspects of this controversy and discusses the current status of transmyocardial laser revascularization, as well as possible future directions.