Frequency and potential consequences of origin of the left vertebral artery (or the arteria thryoidea ima) directly from the aortic arch.

Described herein are findings in a 58-year-old man in whom necropsy disclosed origin of the left vertebral artery (or the arteria thryoidea ima) directly from the aortic arch. No functional consequences resulted. Study of previous publications disclosed the frequency of this anomaly in adults to be approximately 3.5%. Dissection has been reported to be more frequent in the left vertebral artery when it arises directly from the aorta than when it arises from the left subclavian artery.