Distinct Radioanatomic Features and Treatments for Spinal Epidural Arteriovenous Fistulae

Spinal epidural arteriovenous fistula (SEDAVF) is a novel clinical entity that is distinct from spinal dural arterovenous fistula, although both diseases manifest as venous congestive myelopathy. We reviewed nine cases of SEDAVF to elucidate its pathogenesis and radioanatomic features and to optimize treatment strategy. All cases exhibited similar angioarchitecture, with a single shunt at the epidural venous plexus that drains into the intradural perimedullary vein and connects to the ventral spinal vein. Interestingly, all lesions were located on the ventral side of the lower lumber and sacral region, and shunts were located ventrally in association with the epidural pouch suspected to be isolated as extradural venous lake. This may be the result of the specificity of the feeding artery and a congenital shift in the distribution of the venous drainage system at the terminal film and conus. We explored two options for the treatment for SEADF: endovascular transarterial embolization and surgical shunt interruption. Among our patients, three were treated using the endovascular approach and six were treated with surgery. While both treatments were effective at improving symptoms, the delay between disease onset and diagnosis precluded a complete cure. Early diagnosis and adequate treatment based on precise knowledge of the angioarchitecture and pathogensis of SEDAVF is essential for improved outcomes.