Spontaneous closure of a superior sagittal sinus dural arteriovenous fistula with an extensive angioarchitectural network: A case report and systematic review of the literature

BACKGROUND: Intracranial dural arteriovenous fistulas (DAVFs) have been documented to occasionally spontaneously regress. However, the mechanism responsible for this occurrence remains speculative. METHODS: We present a case of a Borden II – Cognard IIa+b DAVF involving the superior sagittal sinus (SSS) with bilateral external carotid artery supply that regressed spontaneously. A systematic literature review was conducted to explore the current theories explaining the spontaneous regression of DAVFs according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. RESULTS: A total of 26 studies and 54 cases were included in our results. Of the included cases, 57.14% of cases were Borden I, 16.33% were Borden II, and 26.53% were Borden III. Ruptured status or intracranial hemorrhage was documented in 24.1% of all cases, the majority of which (69.2%) were in cases with aggressive lesions (Borden II or greater). The most commonly involved location was the transverse sinus (38.89% of cases, n = 21), and the SSS was only involved in 12.96% of all cases. 50% of included cases proposed a mechanism responsible for spontaneous regression. The most frequently proposed mechanisms were thrombosis of the involved sinus/chronic inflammatory changes or direct endothelial injury, endoluminal stasis, and thrombogenic effects of contrast medium during angiography. We present the case of a 54-year-old woman with an aggressive ruptured DAVF that likely developed following a pediatric traumatic brain injury that was left untreated before she presented to our institution after significant delay. Her DAVF regressed on repeat angiography before neurovascular intervention without a clear identifying mechanism as proposed by the current literature. CONCLUSION: Our results suggest that spontaneous regression is not necessarily associated with lower risk DAVFs. The present case offers a unique long-term insight into the natural history of an aggressive ruptured DAVF of the SSS that regressed without intervention. Further research into the natural history of DAVFs will be helpful in deducing key factors leading to spontaneous regression.