Case 1. A 69-year-old male, who had undergone coronary artery bypass grafting with saphenous vein graft for acute myocardial infarction 16 years previously, was admitted into our hospital for heart failure and recurrent angina. Coronary angiography showed occlusion of the graft and 75% stenosis in the proximal circumflex artery. Left ventriculography showed end-diastolic volume of 216 ml and ejection fraction of 24%. Dor operation combined with redo coronary artery bypass grafting was performed. Postoperatively, the ejection fraction improved to 53% and the cardiac index improved from 1.8 to 2.2 l/min/m2. Case 2. A 67-year-old male, who had undergone double coronary artery bypass grafting using saphenous vein grafts for acute myocardial infarction 8 years previously, was admitted into our hospital for heart failure and recurrent angina. Coronary angiography showed occlusion of the 2 grafts and 99% stenosis of the proximal left anterior descending artery. Although the left ventricle was slightly dilated, echocardiography demonstrated a thrombus in the left ventricle. Dor operation was performed concomitantly with removing of the thrombus and redo coronary artery bypass grafting. Postoperatively, the ejection fraction improved to 68% and the cardiac index improved from 1.6 to 2.3 l/min/m2. When the patients underwent coronary artery bypass surgery with saphenous vein grafts for acute myocardial infarction, they could be susceptible to left ventricular asynergy and graft failure on the long run. Therefore, the patients who need redo coronary revascularization may be potential candidates for Dor operation, and they require close examination regarding the myocardial viability, volume and shape of the left ventricle.