Right Vertebral Artery Arising From Ipsilateral Common Carotid Artery With Severe Stenosis of Ostio-proximal Segment of Aberrant Right Subclavian Artery: A Rare Life-Saving Variant

Abstract

Anomalous origins of vertebral arteries are rare vascular anomalies that are incidentally identified during computed tomography, magnetic resonance imaging, or digital subtraction angiograms. We present the case of a 45-year-old male who had gangrene of the right ring finger associated with absent radial, ulnar, and brachial artery pulses. A computed tomography angiogram of the upper limb including the arch of aorta showed an aberrant right subclavian artery having near-total stenosis at the origin. An anomalous origin of the right vertebral artery from the right common carotid artery was also noted. This incidental variant anomaly of the vertebral artery was vital in this case as it spared the posterior cerebral circulation from vascular insufficiency complications. It is also important for future head and neck endovascular interventions to avoid inadvertent arterial injury.

Keywords: aberrant right subclavian artery; cerebral circulation; right brachiocephalic artery; right vertebral artery variant; variant anatomy; vertebral artery.

Figure 1. Oblique reformatted thin axial CTA and MIP images showing aberrant RSA origin from the arch of aorta with severe stenosis at the ostio-proximal segment (arrowheads). Note the variant origin of right vertebral artery arising from right common carotid artery (1B, white arrow).

CTA: computed tomographic angiography; RSA: right subclavian artery; MIP: maximum intensity projection

Figure 2. (A) Sagittal MIP, (B) Coronal MIP, and (C) VR reformatted images showing variant vertebral artery arising from common carotid artery (white arrows).

MIP: maximum intensity projection; VR: volume rendering