Giant saccular aneurysm of the left main coronary artery.

Coronary aneurysms represent anomalies identified in 0.15%–4.9% of patients undergoing coronary angiography. At present, there is no uniform definition of this pathology. Aneurysms of the left main coronary artery (LMCA) are extremely uncommon, with an incidence of 0.1%. It has been demonstrated that atherosclerosis is the main cause of these anomalies in adults, and Kawasaki disease in children and adolescents. Other causes include connective tissue disorders, trauma, vasculitis, congenital, mycotic, and idiopathic. These dilated sections of the coronary artery are not benign pathology because they are subject to spasm, thrombosis, and subsequent distal embolism, spontaneous dissection and rupture. Treatment options include anticoagulation, custom-made covered stents, reconstruction, resection, and exclusion with bypass. Our report on an old case illustrates the giant saccular LMCA aneurysm leading to myocardial ischemia due to coronary steal phenomenon.