Surgical and endovascular treatment of spinal dural arteriovenous fistulas: long-term disability assessment and prognostic factors

Abstract

Object. The authors assessed clinical outcomes of patients with treated spinal dural arteriovenous fistulas (DAVFs) and investigated prognostic factors. Methods. Thirty consecutive patients with spinal DAVFs were treated at the authors' institution during the past 15 years: seven underwent surgery; seven underwent surgery after failed embolization; and 16 underwent embolization alone. The outcomes of gait and micturition disability were analyzed. Follow up averaged 3.4 years (range 1 month–11.8 years). Age, duration of symptoms, pre- and postintervention magnetic resonance (MR) imaging findings, and preintervention disability were correlated with outcome. Seventeen patients (57%) experienced improved gait, 12 (40%) were unchanged, and one (3%) was worse. In 11 patients (37%) micturition function was improved, in 15 (50%) it was unchanged, and in four (13%) it was worse. Gait disability, as measured by the Aminoff—Logue Scale, was significantly improved after treatment, from 3.4 ± 1.4 (average ± standard deviation) to 2.7 ± 1.5 (p = 0.007). Mean micturition disability scores decreased, but not significantly, from 1.9 ± 1 to 1.6 ± 1.1 (p = 0.20). Preintervention gait disability was not associated with improvement except for patients with Aminoff—Logue Scale Grade 4 disability (eight of nine improved; p = 0.024). For patients treated within 13 months of symptom onset, mean micturition disability decreased (p = 0.035). No association was found between clinical improvement and age, a symptom duration less than 30 months, or pre- and postintervention MR imaging—documented spinal cord edema. Conclusions. Spinal DAVF treatment significantly improved patients' mean gait disability score by almost one grade at last follow up. The mean micturition disability score was not significantly improved, unless treatment was performed within 13 months of symptom onset. Longer and more uniform follow-up study is needed to determine if improved and stabilized clinical outcomes are sustained.