Spinal extradural arteriovenous fistula with intradural drainage: three surgical cases with long-term follow-up.

Spinal extradural arteriovenous fistulas (SEDAVF) with intradural drainage are uncommon vascular lesions that cause venous congestive myelopathy. We present three SEDAVF with intradural drainage treated with surgical disconnection of the intradural drainage via a single level laminectomy, followed by transarterial embolization (TAE) with Onyx if spontaneous thrombosis of the extradural fistula did not occur spontaneously. All patients improved their neurological condition and no congestive myelopathy recurrence was noted after mean follow-up of 84 months. We believe that SEDAVF with intradural drainage constitute a specific entity that should be included in the classifications of spinal arteriovenous malformations.