Interrupted aortic arch

Interrupted aortic arch is a congenital anomaly of the branchial arch arteries. It is caused by obliteration of the left fourth branchial arch artery. The proximal part of the aortic arch artery divides to form the brachiocephalic trunk and left common carotid arteries. However, there is no continuity of the arch beyond these branches. Instead, to supply the rest of the systemic circulation, the ductus arteriosus is patent and greatly dilated. The left and right subclavian arteries may both take origin from the continuation of the aorta distal to its junction with the ductus arteriosus. This part of the aorta is derived from the left dorsal aorta.