Vertebral Artery Anatomy

Abstract

Anomalies that must be considered before surgery include interforamenal anomalies, extraforamenal anomalies, and arterial anomalies. The intraforaminal anomalies involve midline migration, which places the VA at direct risk during corpectomy. Extraforaminal anomalies are related to VAs entering the transverse foramen at a level other than C6, which can increase the risk of injury during the anterior approach to the cervical spine. Arterial anomalies can be fenestrated, hypoplastic, or absent. These raise concern with the ability to maintain cerebral perfusion in the setting of damage to one of the VAs with the presence of contralateral arterial abnormality.