Indirect myocardial revascularization: great therapeutic potential if understanding the mechanisms.

Strategies for indirect myocardial revascularization in end stage ischemic coronary artery disease have been described and are still developing, including transmyocardial laser revascularization, ischemic preconditioning, low-energy shock wave therapy, or epicardial transplantation of latissimus dorsi muscle flap. All of them are intended to induce angiogenesis and generate neocollaterals to improve regional myocardial perfusion. The latter has been performed in some patients in whom no direct revascularization of the target vessel was possible because of diffuse calcification, small vessel disease, or in patients with multiple stents implanted in a single vessels, leaving no room for bypass anastomosis. We report a successful reperfusion of a formerly occluded left anterior descending coronary artery (LAD) in a patient in whom a free latissimus dorsi muscle flap had been transplanted onto the ischemic anterior epicardial area because of massive LAD calcification and occlusion in December 1995. A 55-year-old male underwent coronary artery bypass grafting for double vessel disease in December 1995 with a venous bypass graft to the right coronary artery. At this time, an additional bypass graft to the occluded LAD was planned. However, the LAD was completely and heavily calcified. Because of the proximal occlusion of the LAD and his diffuse, advanced calcification up to the apex, no direct revascularization was feasible. Therefore, a free latissimus dorsi muscle flap had been transplanted onto the ischemic anterior epicardial area. The arterial perfusion of the muscle was achieved by implantation of the supplying artery directly in the ascending aorta and the venous blood drainage into the right atrium. After an uncomplicated postoperative course, the patient was discharged, did well in his daily life, and had returned to our cardiologists for routine follow-ups every 2 to 3 years. More than 16 years later, in April 2012, the patient was rereferred to our center with angina Canadian Cardiovascular Society class II. The coronary angiogram revealed an occluded venous graft to the right coronary artery. In addition, an open arterial inflow to the muscle flap was identified from which multiple neocollaterals evolved, supplying the anterior wall of the left ventricle via the native, formerly occluded LAD (online-only Data Supplement Movies I and II and Figure 1)