Natural right internal mammary artery to left circumflex artery bypass.

A 76-year-old man who had a history of diabetes mellitus, hypertension, and hyperlipidemia was referred to our hospital for surgical intervention of his coronary artery. He does not have any history of chest trauma previously. This patient also had a history of 2 previous percutaneous coronary artery interventions. In 2000, he underwent stent insertion to the right coronary artery (RCA) and the left circumflex artery (LCX) because of posterior acute myocardial infarction. In 2007, stent insertion was performed for a newly developed lesion of the RCA. Since that procedure, the patient was stable without chest pain. However, in 2013, he complained of severe chest pain on exertion and was emergently admitted to a local hospital. An ECG showed anterior wall ischemia. Acute coronary syndrome was suspected. Emergency coronary angiog-raphy was performed and revealed tight left main stenosis, 75% stenosis of the proximal left anterior descending artery, 99% stenosis of the proximal LCX, and 90% stenosis of the RCA. There was flow competition between the native LCX and the collateral artery (Figure 1, Movie I in the online-only Data Supplement). An internal mammary artery angiography was performed and showed that 1 of the pericardial branches of the right internal mammary artery (RIMA) arose from the proximal part of the RIMA, communicated with the proximal LCX, and perfused the entire LCX area (Figure 2, Movie II in the online-only Data Supplement). There was no communication between the left internal mammary artery (LIMA) and the coronary arteries. This patient underwent coronary artery bypass grafting as follows: the LIMA to the left anterior descending artery, the RIMA to the first diagonal branch, and the saphenous vein graft to the posterior descending artery and the posterior lateral artery). When the RIMA was harvested, a large pericar-dial branch of the RIMA was identified right to the thymic tissue. The branch coursed caudally and posteriorly toward the pericardium. This branch was preserved, and the RIMA was used for in situ grafting to the first diagonal branch as usual. The postoperative course was uneventful, and the patient was extubated the next morning. A postoperative coronary angi-ography indicated that all grafts were patent. An angiography of the saphenous vein graft to the diagonal branch showed that the graft was patent and showed retrograde filling of the pericardial branch of the RIMA (Figure 3, Movie III in the online-only Data Supplement). Extracardiac coronary collateral perfusion from the internal mammary artery …