Cauda equina arteriovenous fistula supplied by proximal radicular artery and concomitant sacral dural arteriovenous fistula: A case report and literature review.

backgroundCauda equina arteriovenous fistulas (AVFs) fed by the proximal radicular artery are exceedingly rare. Spinal dural arteriovenous fistulas (DAVFs) in the sacral region are rare and usually misdiagnosed. We report a case of a cauda equina AVF with concomitant sacral DAVF. We also review the coexistence of multiple types of spinal vascular malformations in a single patient. CASE DESCRIPTION: A 54-year-old man presented with progressive weakness of the lower extremities for 1 month. Magnetic resonance imaging (MRI) of the lumbosacral and thoracic spine showed spinal cord congestion, extending from the conus medullaris to the level of T7, and abnormal tortuous and dilated flow void, running from the level of L5 to T12 along anterior surface of the spinal cord. Spinal angiography demonstrated the fistula at the level of L2 below the conus medullaris. Based on intraoperative findings, the cauda equina AVF supplied by the proximal radicular artery with cranial drainage through the enlarged radicular vein was confirmed and successfully obliterated. Another enlarged arterialized radicular vein running parallel to another cauda equina nerve root is observed with unknown origin. After the operation, the patient showed mild improvement of his symptoms. Follow-up MRI and contrast-enhanced MR angiography revealed an another sacral DAVF vascularized by the lateral sacral artery.

conclusionThe coexistence of different spinal vascular malformations in a same patient is extremely rare. Most authors of several studies hypothesized that venous hypertension and thrombosis due to the presence or treatment of the first spinal vascular lesion may produce a second DAVF.