Abstract
This report describes a case of surgical treatment for a coronary artery saccular aneurysm of the left main bifurcation. A coronary artery saccular aneurysm (7 mm × 10 mm) and three vessel disease, including the left main trunk, were diagnosed by coronary angiography. A surgical resection and saphenous vein patch repair of the left main coronary artery aneurysm was performed concomitantly with coronary artery bypass grafting. The pathological findings of the aneurysm clarified that the aneurysm wall was atrophic and extremely thin because of a collapsed trilaminar arterial structure due to atherosclerosis. A coronary computed tomographic scan revealed no aneurysmal formation in the patent left main trunk and patent grafts 3 years after surgery.