Long-term Outcomes after Staged and Multimodal Treatment for Diffuse Intracranial Dural Arteriovenous Fistulas Involving Interconnected Dural Sinuses: A Single-center Case Series

Abstract

Diffuse intracranial dural arteriovenous fistulas involving interconnected dural sinuses are uncommon lesions with complex angioarchitecture and an evolving clinical course. However, long-term treatment outcomes and surveillance strategies remain poorly characterized. We retrospectively reviewed 49 consecutive patients with intracranial dural arteriovenous fistulas treated at our institution for 10 years. The study included 9 patients with diffuse intracranial dural arteriovenous fistulas involving 2 or more interconnected dural sinus compartments. Endovascular treatment was used as the first-line therapy for symptomatic or hemodynamically significant lesions, and stereotactic radiosurgery was incorporated for residual low-flow shunts or selected lesions that were not amenable to safe or complete endovascular treatment. Follow-up magnetic resonance imaging and digital subtraction angiography were used to assess shunt occlusion, recurrence, and newly detected shunt lesion in other dural sinus compartments. Nine patients were male. On a sinus-compartment basis, 30 shunt-related sinuses were identified. Shunting most commonly involved the transverse-sigmoid sinus, followed by the torcular confluence and the superior sagittal sinus. Cortical venous reflux was observed in 6 patients. Five patients showed multi-compartment shunt involvement at diagnosis, whereas 4 indicated newly detected shunt involvement during follow-up. Staged multimodal treatment achieved complete occlusion in 18 shunting compartments and partial occlusion in 8 with improved venous drainage; the remaining 4 were managed conservatively. The mean follow-up was 49 months (range, 20-70 months), and patients had favorable outcomes with a modified Rankin Scale score of 0-2. Diffuse intracranial dural arteriovenous fistulas may follow an evolving angiographic course even after treatment, underscoring the importance of long-term follow-up and individualized staged management.