Giant coronary artery aneurysm associated with medial mucoid degeneration.

A 52-year-old man underwent surgical repair for coronary arteriovenous fistula including patch closure of two exitus of the fistula, double ligation of the dilated right coronary artery, and coronary bypass grafting to the right coronary artery with saphenous vein graft at the age of 25. Then, twenty-seven years later, a multi-detector computed tomographic scan revealed an aneurysmally dilated right coronary artery (4.8 cm), fistula, and saphenous vein graft. The aneurysm was resected and histologically mucoid degeneration in the media of the aneurysmal wall was detected.