Background and Purpose Spinal epidural arteriovenous fistulas (SEDAVFs) are an increasingly recognized form of spinal vascular malformation. The aim of this study was to analyze the clinical presentation, imaging findings and treatment outcomes of spinal epidural arteriovenous fistulas in a contemporary single-center series.

Materials and Methods Consecutive patients diagnosed and/or treated for SEAVFs at our institution between January 2000 and November 2018 were included. Data were collected on demographics, clinical presentation, imaging findings and treatment outcomes. All cross-sectional and angiographic imaging were reviewed by a diagnostic and interventional neuroradiologist and endovascular neurosurgeon. All patients underwent at least 3 months of clinical follow-up.

Results Forty-nine patients were included. Median follow-up was 21 months. 29 patients (59.2%) were males and mean age was 63.5±14.8 years. The median time from symptomatic presentation to diagnosis was 12 months. The most common finding on lumbar spine MRI were T2 hyperintense signal in the conus (42 patients, 85.7%), perimedullary flow voids (34 fistulas, 69.4%) and cord enhancement (30 patients, 61.2%). Thirty-eight patients had a spinal MRA and 35 (92.1%) had a pouch of contrast/venous varix in the epidural space. All patients on DSA had a pouch of contrast in the ventral or lateral epidural space at the site of the abnormal fistulous connection (49 lesions, 100.0%). 40 SEAVFs (81.6%) were located in the lumbosacral spine. A total of 40 patients underwent endovascular embolization for treatment of their fistula. One patient suffered a treatment related complication (2.5%). Of the treated patients, 4 patients (10.0%) had residual fistula requiring additional embolization or surgery.

Conclusions SEDAVFs have similar findings to spinal dural arteriovenous fistulas on conventional MRI with high T2 cord signal, cord enhancement and perimedullary flow voids. However, they have a characteristic appearance on spinal MRA and DSA with a large pouch of epidural contrast. Endovascular embolization is safe and effective for treatment of these lesions.

Disclosures W. Brinjikji: None. H. Cloft: None. G. Lanzino: None.