Unusual origin of left vertebral artery from the arch of aorta: a case report.

The aortic arch is a continuation of the ascending aorta, being located in the superior mediastinum. Three branches, the brachiocephalic trunk, left common carotid artery and left subclavian artery usually branch from the aortic arch. These branches may branch from the beginning of the arch or the upper part of the ascending aorta by varying distances between them. The brachiocephalic trunk later divides into right common carotid artery and right subclavian artery. Variations in the branching pattern of the aortic arch range from differences in the distance between origins of different branches to number of branches [1, 2].In approximately 48 year old Indian male cadaver during routine dissection, we reported a variant of aortic arch branching pattern where the left vertebral artery arises from the arch of aorta in between the origin of the left common carotid artery and left subclavian artery whereas the right vertebral artery took its normal origin from right subclavian artery.The anatomic and morphologic variations of the left vertebral artery are significant for diagnostic, surgical procedures and vascular radiology in the head and neck region [3]. It is of clinical importance to know the origin and course of prevertebral segment of the vertebral artery in detail and being aware of the possible variations.