A ruptured craniocervical junction perimedullary arteriovenous fistula successfully treated through flow diversion: A case report.

Background: Spinal arteriovenous fistulae (AVF) located at the craniocervical junction (CCJ) are rare and usually present with hemorrhage. Bleeding is usually attributed to arterial feeders arising from the anterior spinal artery (ASA) and aneurysms located on such feeders. Perimedullary AVFs are typically found on the ventral surface of the spinal cord, which makes them difficult to treat through traditional microsurgical methods. In addition, their unique vessel angioarchitecture frequently precludes safe embolization. We present the first case of a CCJ perimedullary AVF successfully treated using flow diversion. Case Description: A 76-year-old man was brought to the emergency department after suddenly losing consciousness. On further evaluation, infratentorial subarachnoid hemorrhage and a perimedullary AVF at the ventral surface of the spinal cord were identified. The ASA originated from the left V4 segment, providing a single feeder to the lesion associated with a 2 mm aneurysm. After initial antiplatelet loading, 8 hydrophilic polymer-coated flow diverters were deployed to cover the ASA's origin in two sessions, achieving the complete occlusion of the lesion and the aneurysm 5 months later, without evidence of ischemic lesions. Conclusion: CCJ perimedullary AVFs can bleed with devastating consequences. These lesions can be challenging to treat through traditional microsurgical or endovascular techniques. Progressive occlusion with flow diversion is feasible in single-feeder AVFs, theoretically allowing blood flow reorganization to the cervical spinal cord.