Spinal Dural Arteriovenous Fistula Symptomatic after D12 Vertebral Body Fracture: Case Report and Literature Review

Introduction: Spinal dural arteriovenous fistulas (SDAVF) are abnormal connections between arteries and veins of the spine with the passage of blood from arteries to veins without going through the capillary network. It is a rare spinal vascular malformation with an annual incidence of 5–10 cases per million and represents 3%-4% of all space-occupying lesions affecting the spinal cord. They occur predominantly in men (80%), commonly involve the thoracolumbar spine, and usually cause progressive myelopathy because of venous congestion of the spinal cord. It is widely accepted that SDAVF is fed by the radiculomeningeal artery, located on the dura mater of the spinal nerve root sleeve, and drains into the radiculomedullary vein. SDAVF has a variable course ranging from acute onset that mimics anterior spinal artery syndrome to chronic and progressive symptoms. Untreated, it may progress to subacute necrosis of the spinal cord with permanent and severe impairment, including limb paralysis and loss of sphincter function. Herein, we describe a case in which symptoms started after a vertebral fracture.

Objective: Report a case in which symptoms associated with a SDAVF started after a vertebral body fracture and review the literature associated.

Method: Case report followed by a literature review performed in PubMed with the terms “Spinal Arteriovenous Fistula”.

Results: Male, 59 years old, previously healthy, on April 24^th, 2018 fell of 1 meter of height, without symptoms at the scene, but for the pain. On April 26th evolved with progressive loss of strength in lower limbs, no sensory alterations nor bladder dysfunction. Sought medical care in HC-FM-USP and at physical examination was conscious and oriented, muscle strength demonstrating a paraparesis grade IV and no sensory impairments. A medical work-up was performed starting with a thoracolumbar CT, which showed an A2 AOSpine fracture of the twelfth thoracic vertebra, without spinal cord compression. Investigation went on with a spinal MRI, showing the presence of flow voids on the cord surface, suggesting a SDAVF. An angiography was performed and partially embolization of the fistula was done on account of the difficulty to approach the catheter because of the small diameter of the feeding artery. Therefore, microsurgical treatment of the fistula was performed, and patient was discharged with improvement of the paraparesis and rehabilitation programmed.