Spinal Osseous Epidural Arteriovenous Fistula with Intradural Reflux: A Case Report

The authors report a rare case of spinal osseous epidural arteriovenous fistula (AVF) with intradural reflux. A 71-year-old lady with a past history of a T12 compression fracture and neurofibromatosis type 1 presented with progressive paraparesis. Magnetic resonance (MR) images of the thoracolumbar spine showed edema of the spinal cord and flow voids. Catheter angiography revealed segmental arteries from T11 to L1 feeding an AVF in the epidural space. The AVF drained not only into the epidural venous plexus but also into the perimedullary veins. Of note, there was an intraosseous drainage route that involved the basivertebral vein of T12. Under the diagnosis of spinal osseous epidural AVF with intradural reflux, surgical interruption of the intradural arterialized draining vein was performed. Spinal osseous epidural AVF with intradural reflux is rare with only four cases reported in the past. We believe that spinal osseous epidural AVF should be recognized as a variant of spinal epidural AVF.

Spontaneous Spinal Osseous Epidural Arteriovenous Fistula with Long Segments of Prominent Epidural Venous Drainage Causing Severe Compressive Thoracic Myelopathy Successfully Treated with Combined Endovascular and Surgical Treatments: A Case Report and Review of the Literature

The authors describe an extremely rare case of spinal osseous epidural arteriovenous fistulas (SOEAVFs) with unique characteristic features. A 25-year-old man presented with progressive weakness and paresthesia of the lower extremities for 1 month. Magnetic resonance imaging of the thoracic spine showed an extradural dilated vascular flow void structure extending from T4 to T8 levels with abnormal hyperintense T2 signal from T6 to T8 levels. Magnetic resonance angiography and spinal angiography revealed unique features of SOEAVF supplied by multiple small arterial feeders of intercostal arteries converging into a dilated round venous sac corresponding to a bony defect of T7 lamina and spinous process. The venous drainage directly drained into prominent epidural venous plexus extending from the level of T4 to T8 without intradural venous drainage, causing severe compressive myelopathy. Transarterial embolization was performed using N-butyl cyanoacrylate through the main feeder. Subsequently, he successfully underwent laminectomy and total excision of the fistula and large epidural draining venous plexus. Histopathology confirmed spinal vascular malformations with evidence of previous embolization. He gradually improved until being ability to walk independently 3 months later. Follow-up spinal angiography confirmed complete resection of SOEAVF. The patient has remained clinically asymptomatic 5 years after operation.