Long-term outcome in patients treated for benign dural arteriovenous fistulas of the posterior fossa

Dural arteriovenous fistula (dAVF) draining into a dural sinus without recruitment of cortical veins is regarded as relatively benign lesion and treatment is advocated only if the patient is severely affected by the symptoms. The aim of this study was to compare the clinical outcomes in patients who received endovascular treatment or no treatment, respectively. Twenty-one patients presented consecutively with pulsating tinnitus as leading symptom and with angiographically proven dAVF at the transverse or sigmoid sinus (Borden I). Nine patients underwent different types of endovascular embolisation, and 12 patients were not treated. After a median follow-up period of 2.3 years, outcome was evaluated by assessing the patients' symptoms and scores on the mRS, EQ-5D, SF-36 and HIT-6 scales. Complete long-term closure of the dAFV was achieved in two out of nine cases; subtotal occlusion was found in seven patients. Pulsating tinnitus persisted less frequently in treated than in untreated patients. Neurologic symptoms occurred in both groups. Neither these findings nor the clinical outcome and scores on the quality-of-life scales varied substantially between the two groups. Partial treatment did not resolve the clinical symptoms of patients with "benign" dural AVF in the follow-up and was not clearly superior to conservative management. These results suggest that embolisation should be offered only if there is a possibility of a complete cure without major periinterventional risks. Further studies should be performed to assess the risk-benefit ratio of pursuing more aggressive treatment strategies in patients with unbearable symptoms.