MR angiographic findings of aberrant right subclavian artery with agenesis of the left common carotid artery and anomalous origin of the vertebral arteries

Congenital aortic arch anomalies and variants have been extensively characterized in the medical literature. Proper identification of these anomalies is important when surgical or percutaneous interventions are indicated.We present a case of a 48-year old male who presented to the emergency department with altered mental status. Magnetic resonance angiography (MRA) findings revealed an aberrant right subclavian artery (ARSA), early bifurcation of the right common carotid artery (CCA) with anomalous origin of the right vertebral artery (VA) from the right common carotid artery bifurcation, anomalous left vertebral artery originating from the aortic arch, and absent left common carotid artery with independent origins of the left external carotid artery (ECA) and internal carotid artery (ICA). No other abnormalities were identified, and the patient demonstrated no symptoms attributable to his vascular anomalies.To our knowledge, this unique combination of anomalies has never been reported in the literature. With an understanding of embryological pathways, even exceedingly rare anomalies like this one can be explained.