An unusual right vertebral artery variation accompanying to bovine arch: A case report

In a 74-year old male patient, brachiocephalic trunk and left common carotid artery are sharing a common root (bovine arch) and right vertebral artery (VA) variation was detected incidentally during computed tomography angiography for occlusion of common carotid artery. Right VA branches from the aortic arch (aberrant VA) and forwards retroesophageally and retrotracheally during its course and then entered cervical 7th transverse foramen whereas left VA branches from the subclavian artery and entered cervical 6th transverse foramen. The patient has not any symptom such as dyspnea and dysphagia. The most common anatomic variation of aortic arch is the bovine aortic arch. Incidence of the bovine aortic arch varies between 0.9% 27.4% in the literature. Like in the present case, branching of the right vertebral artery from aortic arch is very rare.