Left aortic arch (posterior or circumflex type) with right descending aorta ∗

Abstract

ANY M anomalies complicate the development of the primitive aorta. These deviations may involve the thoracic aorta itself (which can be left, right or double) or only its branches. A persistent arterial canal or its fibrous transformations (arterial ligament) may be often associated with additional malformations. An aortic diverticulum at the junction of the horizontal and descending segments is an important anomaly which aggravates existing serious malformations. Coarctation of the aorta is a minor manifestation of such malformations. Major manifestations are complete or partial truncus arteriosus and pulmonary aortic fistulas. Of all these anomalies, posterior or circumflex aortas are of special interest, since the retroesophageal position of their horizontal portion produces a curious diagnostic deviation of the esophagus and trachea. These complications are easily recognized when barium fills the esophagus. The most frequent manifestation of these malformations is a right aortic arch with left descending aorta. This occurs in 4 to 5 per cent of patients with tetralogy of Fallot and may be well tolerated. On the other hand, the type of left aortic malformation (aortic arch to the left ; descending aorta to the right) is extremely rare. We recently observed such a case which we believe to be the fifth in the literature.