Spinal epidural arteriovenous fistula: a unique pathway into the perimedullary vein. A case report.

Spinal dural arteriovenous fistulas (AVFs) are rare vascular malformations in the spinal dura, fed by dural branches of the radicular arteries, and drain primarily into intradural venous plexuses. They may cause elevated medullary venous pressure and produce a progressive myelopathy. We describe a case of AVF in the epidural space of the previous surgery site of L3 and it showed a unique complex venous pathway into the perimedullary vein, leading to classic clinical symptoms of venous congestion in the spinal cord. The shunt was draining into bilateral epidural venous plexus and then to the paravertebral veins at the level of L2. The venous outflow entered to the epidural space again and finally refluxed into the intradural perimedullary vein.