Functional Outcome in Patients with Dural Arteriovenous Fistulae after Surgical Treatment

Spinal dural arterio-venous fistulas (SDAVF) are rare vascular pathologies. Degree of symptom improvement after surgery remains unclear. We evaluated surgically treated SDAVF patients for functional outcome and symptom improvement. Retrospective inclusion of consecutive patients treated surgically in our department between 2007-2019. We measured functional outcome using the McCormick Scale and modified Japanese Orthopaedic Association (mJOA) score. We included 27 patients with a median follow-up of 8.8 months (IQR 27.8). Mean age was 61.8 years (SD 8.4), 40.7% were female. Most frequent location was the thoracic spine in 15 (55.6%) followed by lumbar in 8 (29.6%), cervical in 3 (11.1%) and sacral spine in one patient (3.7%). Most common presenting symptom was progressive myelopathy (24/27 patients, 88.9%). In all patients the SDAVF was completely resected; however, four patients (14.8%) required a second surgery. Six patients (22.2%) deteriorated immediately after surgery with five recovering to baseline upon discharge. On discharge, presenting symptoms had improved in 17 patients (63%); 8/25 patients (32%) had a McCormick score of 1. Twenty (74.1%) continued to improve on follow-up. In total 23/27 patients (85.2%) improved. In the univariable analysis mJOA score on admission was associated with mJOA score on follow-up (coefficient 0.6, 95%CI 0.4-0.81, p < 0.001), whereas age was inversely associated (coefficient -0.1, 95%CI -0.19-0.01, p = 0.08). Untreated SDAVF leads to progressive myelopathy which may result in considerable disability. Surgical disconnection and resection provides a safe treatment option with low perioperative morbidity and excellent chances for symptom improvement or progression prevention.