Delayed treatment of spinal dural arteriovenous fistulas negatively impact long-term neurological outcomes: a longitudinal cohort study

Introduction: Dural arteriovenous fistulas are rare vascular malformations that affect the brain and the spinal cord. Spinal dural arteriovenous fistulas (sdAVFs) are the most frequently encountered vascular malformation affecting the spinal cord. Due to the unspecific nature of the presenting symptoms, delays in the diagnosis of sdAVFs are not uncommon. To identify predictors of long-term neurologic outcomes following either open surgical or endovascular treatment of spinal dural arteriovenous fistulas (sdAVFs).

Methods: This retrospective, population-based cohort study examined 34 patients consecutively diagnosed with sdAVFs at a tertiary care center between 2005 and 2020. Patients were assessed using the Aminoff-Logue disability scale (ALS) at various time-points including symptom onset, primary care visit, first specialist outpatient visit, as well as both short and long-term follow-up. The postoperative long-term gait and bladder ALS scores constituted the primary outcomes of the study.

Results: The median age of the patients was 65 years, with a male predominance (71%). Most lesions were in the lumbar region (47%). Significant deteriorations in ALS gait and bladder scores were observed preoperatively, followed by postoperative improvements (p < 0.05). There was no difference in outcomes between surgical and endovascular treatments. Older age (OR 1.10, CI: 1.03–1.17, p = 0.007), worse preoperative ALS gait scores (OR 5.12, CI: 2.61–10.05, p < 0.001), and longer time from first specialist outpatient visit to first treatment (OR 1.00, CI: 1.00-1.01, p = 0.040) were independently associated with worse long-term gait outcomes. Only preoperative ALS bladder score was a predictor of long-term bladder function (OR 92.7, CI: 28.0–306.7, p < 0.001).

Conclusion : Both surgical and endovascular treatments for sdAVFs led to significant neurologic improvements. However, treatment delays were associated with less favorable long-term outcomes. Prompt diagnosis and early intervention, prior to symptom progression, may enhance recovery, and help preserve neurological function.