Origin of the right vertebral artery from the right common carotid artery in the setting of an aberrant right subclavian artery: Case and retrospective review to determine frequency

Anomalies of the vertebral arteries are rare. The second most common vertebral artery anomaly is the right vertebral artery arising from the right common carotid artery in the setting of an aberrant right subclavian artery (ARSA). We present a case of this rare anomaly and determine the relative frequency with which the right vertebral artery arises from the right subclavian artery vs the right common carotid artery in the setting of an ARSA by retrospectively reviewing over 500 patients with an ARSA and a contrast-enhanced CT. We found that in the setting of an ARSA the right vertebral artery arises from the right subclavian artery in 84% of patients and from the right common carotid artery in 16% of patients.