Atresia of the left main coronary artery: clinical recognition and surgical treatment.

Atresia of the left main coronary artery is an extremely rare anomaly with very few cases presented in the literature. Even more uncommon are reports of successful surgical repair. This article concerns two cases of atresia of the left main coronary artery treated surgically with a favourable outcome. The two patients (a 16 year-old boy and a 43 year-old woman) had a different clinical presentation but identical angiographic and morphologic features. The authors examine the embryogenetic defect underlying this anomaly. The differential diagnosis involves two congenital malformations (single coronary artery and anomalous origin of the left coronary artery from the pulmonary trunk) and acquired atherosclerotic disease of the left main coronary artery; the distinguishing features of these conditions are reviewed. Surgical management by means of internal mammary artery revascularization is discussed in light of recent reports about adequacy of blood flow in internal mammary artery bypass grafts.