PT  - JOURNAL ARTICLE
AU  - Bueno, H.F.
AU  - Nimchinsky, E.A.
TI  - Mapping of Anatomic Variants of the Proximal Vertebral Artery in Relation to Embryology
AID  - 10.3174/ajnr.A7942
DP  - 2023 Aug 01
TA  - American Journal of Neuroradiology
PG  - 943--950
VI  - 44
IP  - 8
4099  - http://www.ajnr.org/content/44/8/943.short
4100  - http://www.ajnr.org/content/44/8/943.full
SO  - Am. J. Neuroradiol.2023 Aug 01; 44
AB  - BACKGROUND AND PURPOSE: Variations in the origins and courses of the vertebral arteries are relatively rare but may be clinically meaningful. We hypothesize a relationship between variant origins of the vertebral arteries and their levels of entry to the foramina transversaria.MATERIALS AND METHODS: In this retrospective study of CT angiograms, we document the frequency and types of vertebral artery variants, correlating origins with levels of entry to the foramina transversaria.RESULTS: Vertebral artery variants were observed in 18.7% of a sample of 460 CT angiograms of the neck. Right-sided variants were less common than left (44.2% versus 68.6%, with 12.8% bilateral) and more common than previously thought. The most common variant on both sides was a variant origin proximal to the normal vertebral artery origin and entry at C5. Most right vertebral arteries originating within 2 cm of the origin of the right subclavian artery and left vertebral arteries originating between the left common carotid and subclavian arteries were “high-entry” variants. Most “low-entry” variants, entering at C7, took origin from the arch just distal to the left subclavian artery or at a common origin with the costocervical trunk. Multiple origins or accessory vertebral arteries were also described, and each moiety followed the same rules described for single origins. A map of vertebral artery origins mirrored the map of aortic arch embryology.CONCLUSIONS: Vertebral artery variants follow certain well-defined patterns that correlate with the embryology of the aortic arch and great vessels.CCTcostocervical trunkFTforamen transversariumISAintersegmental arteryLCCAleft common carotid arteryLSCAleft subclavian arteryLVAleft vertebral arteryRSCAright subclavian arteryRVAright vertebral arterySCAsubclavian arteryVAvertebral artery