Left aortic arch with isolated subclavian artery 2012-04-08T02:01:39Z UMLS:C4023280 HP:0011592 The subclavian artery arises from ductus arteriosus. While the ductus arteriosus is patent its blood supply comes from the ductus, hence from the pulmonary artery. After it closes, the blood supply is retrogradely from the vertebral artery via the circle of Willis. Abnormal branching pattern of left aortic arch