Ruptured Anterior Spinal Artery Aneurysm Associated with Bilateral Vertebral Artery Occlusion Treated by Surgical Clipping

BACKGROUND: Spinal artery aneurysms are rare lesions that can occur in isolation or may be attributed to a variety of secondary causes. Chronic bilateral vertebral artery occlusion is an exceedingly rare cause of anterior spinal artery aneurysm, with only one previous case reported in the literature. Surgical treatment of ventrally located anterior spinal artery aneurysms situated at the craniocervical junction presents particular challenges related to the operative approach, which may entail high cervical anterior exposure, posterolateral complete facetectomy/pediculectomy, or far lateral skull base approaches, among others. CASE DESCRIPTION: We present the case of a patient who presented with a ruptured anterior spinal artery aneurysm at the level of C2, associated with a hypertrophied anterior spinal artery due to chronic bilateral vertebral artery occlusion; the second such case reported in the literature. A posterior approach with spinal cord rotation was employed to expose and clip the aneurysm. The patient made an uneventful recovery. CONCLUSION: This report highlights an exceedingly rare cause of anterior spinal artery aneurysm and emphasizes the utility and technical aspects of the posterior approach with spinal cord rotation.