Extradural arteriovenous fistulas involving the vertebral artery in neurofibromatosis Type 1.

Spinal extradural arteriovenous fistulas (AVFs) are rare lesions that may be associated with neurofibromatosis Type 1 (NF1). In these patients, the shunt typically occurs between the V(2) segment of the vertebral artery and the epidural venous plexus. Previously, reported cases have been treated either by using endovascular embolization or, sporadically, by open surgery. In surgical reports, proximal deafferentation or manipulation of the venous portion of the shunt--including suture, resection, or open embolization of the epidural ectasia--was attempted with variable results. The authors report on a case of a young patient with NF1 who underwent emergency surgical disconnection of a cervical extradural AVF after previously unsuccessful endovascular and surgical therapy. The lesion drained into a giant intrathecal varix, causing severe myelopathy. After surgery, the patient recovered almost completely. This experience clarified the surgical anatomy of these malformations and showed that, when surgery is necessary, the optimal treatment providing complete and permanent cure of this condition is direct closure of the epidural shunt pedicle.