Left circumflex artery aneurysm with fistula to the coronary sinus

A giant coronary artery aneurysm with arteriovenous fistula is a unique pathology having few surgical reports. An 82-year-old woman presented with a symptomatic giant left circumflex artery aneurysm with a fistula to the coronary sinus. The left coronary artery was dilated, and an aneurysmal change was visible from the left main trunk to the fistula. Surgery was performed to close the fistula and seclude all parts of the aneurysmal coronary artery. All coronary branches emerging from the aneurysm required bypass grafting. Herein, we present the history of this unusual case and our successful surgical strategy.