Cervical vertebral artery variations: an anatomic study.

In this article, we present 5 cases of uncommon anomalous vertebral arteries and discuss the possible embryologic etiologies. These cases include a left vertebral artery as the 2nd branch off the left subclavian, a left vertebral artery with 2 origins, a right vertebral artery arising as the last branch off the aorta, a right vertebral artery arising as the 2nd branch off the right subclavian artery, and right vertebral artery with proximal duplication as the 2nd branch off the right subclavian artery.