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

Object. The authors assessed clinical outcomes of patients with treated spi nal dural arteriovenous fistulas (DAVFs) and investigated prognostic factor s. Methods. Thirty consecutive patients with spinal DAVFs were treated at the authors' institution during the past 15 years: seven underwent surgery; sev en underwent surgery after failed embolization; and 16 underwent embolizati on alone. The outcomes of gait and micturition disability were analyzed. Fo llow up averaged 3.4 years (range month-11.8 years). Age, duration of sympt oms, 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 imp roved, in 15 (50%) it was unchanged, and in four (13%) it was worse. Gait d isability, as measured by the Aminoff-Logue Scale, was significantly improv ed after treatment, from 3.4 +/- 1.4 (average +/- standard deviation) to 2. 7 +/- 1.5 (p = 0.007). Mean micturition disability scores decreased, but no t significantly, from 1.9 +/- 1 to 1.6 +/- 1.1 (p = 0.20). Preintervention gait disability was not associated with improvement except for patients wit h 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 clinica l 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 ga it disability score by almost one grade at last follow up. The mean micturi tion 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 outcom es are sustained.