Inadvertent anastomosis of internal mammary artery to great cardiac vein: a rare complication of coronary artery bypass surgery.

A 68-year-old man underwent successful 3-vessel coronary artery bypass grafting (CABG): a left internal mammary artery (LIMA) was anastomosed end to side to a large diagonal branch of the left anterior descending coronary artery (LAD) and was then skipped to the distal LAD; and saphenous vein grafts (SVGs) were anastomosed to the circumflex and right coronary arteries. He returned to his cardiologist 2 years later, complaining of new-onset angina. Repeat coronary angiography revealed patent SVGs and a patent LIMA to the 1st diagonal branch of the LAD. However, there was an obvious inadvertent insertion of the LIMA skip graft into the great cardiac vein, instead of the distal LAD (Figs. 1 and 2). The patient underwent successful placement of a drug-eluting stent at the native proximal LAD lesion (Fig. 3). This resulted in a “flush” occlusion of the grafted large 1st diagonal branch. The patient remained free of angina at the 12-month clinical follow-up.