Cervical Origin of the Right Subclavian Artery with a Nonbifurcating Left Cervical Carotid Artery.

A 55-year-old female with no significant past medical history sustained multiple traumatic injuries from a motor vehicle accident. During trauma workup, computed tomography of the head was unremarkable. However, the left internal carotid artery (ICA) could not be visualized on computed tomography angiography. There was concern for left ICA traumatic dissection. Conventional cervical and cerebral angiography revealed a cervical origin of the right subclavian artery (CORSA). There was a nonbifurcating left cervical carotid artery with a single artery supplying all normal branches of the external carotid artery. The left middle cerebral artery was filled via a large left posterior cerebral artery. The left anterior cerebral artery was filled from the contralateral anterior cerebral artery via the anterior communicating artery. Interestingly, both ophthalmic arteries were supplied exclusively from the external carotid arteries (Fig. 1–4). CORSA is a rare congenital anomaly that occurs when there is absence of the right fourth pharyngeal arch artery accompanied by persistence of the right carotid duct. In this setting, Published online: June 22, 2018