Hematomyelia caused by ruptured intramedullary aneurysms of a subaxial cervical epidural arteriovenous fistula: illustrative case.

BACKGROUND: Subaxial cervical epidural arteriovenous fistulas (AVFs) are rare. The authors report the case of a patient with an epidural AVF at the C6 level, resulting in hematomyelia caused by the rupture of feeder aneurysms. OBSERVATIONS: A 77-year-old woman presented with sudden left neck pain followed by dyspnea and tetraparesis. CT imaging revealed intraventricular hemorrhage, subarachnoid hemorrhage, and hematomyelia. MRI showed hematomyelia at the C5-6 level and an edematous lesion from the medulla to the T1 level. Digital subtraction angiography revealed an epidural AVF located at the left C6 nerve root. The epidural AVF was fed by the left C6 radiculomeningeal artery, anterior spinal artery, and deep cervical artery with epidural drainage. Intramedullary aneurysms of the anterior spinal artery were thought to cause the hematomyelia. Transarterial embolization of the shunt via the deep cervical artery resulted in disappearance of the epidural AVF and aneurysms without recurrence for 6 years. LESSONS: This case highlights that transarterial embolization from the extracranial artery can safely obliterate flow-related aneurysms in subaxial cervical epidural AVFs with pial feeders. https://thejns.org/doi/10.3171/CASE25602.