Unusual origin of the ansa cervicalis observed during carotid endarterectomy

The surgical approach of the carotid artery for carotid endarterectomy demands knowledge of normal anatomy and anatomic variation. During carotid endarterectomy, a rare anatomic variant of the origin of the upper root of the ansa cervicalis was found. Contrary to commonly found anatomy, no upper root of the ansa cervicalis originating from the hypoglossal nerve was found. Instead, what seemed to be the ansa cervicalis originated from the vagus nerve and passed over the carotid bifurcation, branching to the infrahyoid muscles. Transection of this ansa cervicalis, for the purpose of good exposure, had no functional or cosmetic consequences.