Interrupted aortic arch refers to a lesion involving a loss of continuity between the ascending and descending aorta due to an absence or atresia of an aortic arch.

There are three forms of interrupted aortic arch.

Type A refers to an interruption between the left subclavian artery and descending aorta.

Type B, the most common, involves a defect between the left carotid artery and left subclavian artery.

Type C, the least common, refers to interruptions between the innominate and left carotid arteries.

In most cases, this defect is accompanied by a ventricular septal defect. Other lesions such as aortic stenosis, bicuspid aortic valves, and abnormal subclavian arteries are also common.

All three forms of interrupted aortic arch require there be a patent ductus areriosus to supply blood to the lower half of the body. Closure of the ductus a few days after birth prevents blood flow, leading to circulatory collapse and metabolic acidosis, both of which threaten survival. The average infant born with an interrupted aortic arch is extremely ill and rarely survives more than a few weeks, typically only a matter of days.

Management of this defect begins with administration of prostaglandin E to maintain a patent ductus arteriosus and blood supply to the lower body. It is recommended that surgical correction take place as soon as metabolic acidosis is controlled.