Long-term risk of hemorrhage and mortality after treatment of high-grade intracranial dural arteriovenous fistulas.

ABSTRACT

BACKGROUND: Despite recent multi-institutional efforts, long-term data on clinical and radiological outcomes after treatment of high-grade dural arteriovenous fistulas (dAVFs) remain scarce. This study aimed to evaluate the long-term risk of hemorrhage and fistula-related mortality after treatment. METHODS: Retrospective analysis of all consecutive patients primarily diagnosed with a high-grade dAVF (Cognard grade 2b, 2a+b, 3, 4) between January 2012 and September 2022 at a large neurovascular center. Primary endpoints were intracranial hemorrhage (ICH) and all-cause mortality after treatment; secondary endpoints were angiographic occlusion, complication rate and neurological deficits. RESULTS: A total of 121 patients underwent 141 treatments (122 endovascular therapy (EVT), 5 radiotherapy, 14 surgery) of which 12 patients (10%) underwent retreatment. Follow-up was available in all patients for a median of 4.2 (IQR 2.5 to 6.6) years. Eleven patients (9%) died during the follow-up period, of which three deaths (2%) occurred after hemorrhagic presentation, one of them attributable to treatment. One death (0.8%) was due to delayed hemorrhage after partial occlusion from EVT. No other post-treatment bleedings occurred. Angiographic follow-up after multimodality treatment was available in 93% of patients after a median of 6 months; the overall occlusion rate was 90%. The overall rate of complications was 25% after EVT and 14% after surgery. The rates of new transient and permanent neurological deficits after EVT were 9% and 3%, respectively. CONCLUSIONS: The long-term rate of re-bleeding or dAVF-related mortality was low when high rates of angiographic occlusion were achieved. The risk for treatment-related complications leading to neurological sequela was low.