Double aortic arch forms a complete vascular ring around the esophagus and trachea. The right dorsal aorta persists between its origin at the seventh intersegmental artery and its intersection with the left dorsal aorta. The right arch is typically larger than the left. Each arch gives off its own carotid and subclavian arteries. Typically, the descending aorta is midline instead of its normal left paraspinal locaion.