The proximal aortic arch is the beginning part of the innominate artery; the distal aortic arch is the isthmus where the ligamentum arteriosum is attached and is also the starting point of the descending thoracic aorta. In the embryonic stage, the aortic arch initially is paired and later turns into a single aortic arch (lactation type). Therefore, the region of the aortic arch should include the portion from the beginning part of the innominate artery to the aorta between the first pair of intercostal arteries. Branches of the aortic arch are the innominate artery, the left common carotid artery, the left subclavian artery, and the left patent ductus arteriosus (after birth, it closes and becomes the ligamentum arteriosum). Different regions of the aortic arch are derived from different embryonic components. Aortic arch deformities inevitably include many variations of each branch. Hence, aortic arch anomalies can be divided into many complex types. Aortic arch malformations include the elongation, twists, lumen atresia, interruption, and vascular ring.