Patent Ductus Arteriosus

The ductus arteriosus is a normal and vital fetal structure that arises from the left sixth aortic arch. It connects the main pulmonary artery to the descending thoracic aorta just distal and opposite to the origin of the left subclavian artery (Fig. 14.1). The pulmonary end usually tapers and is narrower than the aortic end.