Double aortic arch

Double aortic arch is the most common form of vascular ring clinically. The aortic arch divides anteriorly to the trachea into left and right aortic arches, which then encircle the trachea and esophagus. Usually the right arch is thicker than the left, and it then extends posterior to the esophagus and merges to enter the descending aorta, located to the left of the midline of the trunk. Occasionally the left arch is atretic. A complete vascular ring is formed by the aortic arch on both sides of the vessels and esophagus. It is accompanied by an anterior ascending aorta and a retroesophageal aortic arch or a posterior descending aorta. Usually the ductus arteriosus is on the left side and is not a necessary component of the vascular ring, but its length can affect the severity of clinical symptoms. Only 22% of patients have associated congenital cardiac malformations, mainly tetralogy of Fallot and complete transposition of the great arteries. Symptoms in children with double aortic arch can be severe, with clinical manifestations including inspiratory stridor, dysphagia, chronic cough, head retraction, preference for opisthotonic posture, frequent pneumonia, and occasional breath-holding and cyanotic episodes. Chest radiography shows unilateral or bilateral pulmonary hyperinflation due to partial obstruction of the trachea or main bronchus. Barium swallow examination of the esophagus shows bilateral (or predominantly right-sided) sawtooth indentations on the anteroposterior view, with the right-sided indentation being deeper. On the lateral and left anterior oblique views, a large posterior sawtooth indentation is seen, which is characteristic of the retroesophageal aortic arch.