Spontaneous closure of non-cavernous sinus dural arteriovenous fistulas: A case series and systematic review of the literature.

ABSTRACT

BACKGROUND AND PURPOSE: To report 9 new cases of non-cavernous sinus dural arteriovenous fistulas (NCS-DAVFs) that closed spontaneously and systematically review reports of other cases in the literature. MATERIAL AND METHODS: We performed a retrospective analysis of 9 cases from 2 institutions of NCS-DAVFs that closed spontaneously. Using PubMed and Scopus in accordance with the PRISMA guidelines, we systematically reviewed English language articles about NCS-DAVFs showing spontaneous closure. RESULTS: Review of the cases from 2 institutions identified 9 cases of NCS-DAVFs showing spontaneous closure in follow-up magnetic resonance angiography (MRA), and the systematic review of the literature yielded an additional 38 cases, which had been diagnosed by repeated arteriography. Collectively, the patients included 23 men and 24 women with a mean age of 54 years. The shunts were located in the transverse-sigmoid sinus in 24 cases (51%), anterior condylar confluence in 11, and other locations in 12. Based on the venous drainage pattern on arteriography, 27 cases (57%) were classified as low-risk NCS-DAVF (without cortical venous reflux) and 17 were classified as high-risk NCS-DAVF (with cortical venous reflux). Shunt closure was observed within 3 months in 17 cases (36%). Extrinsic predisposing factors for shunt closure were detected in 14 cases (30%). These included angiography in 7 cases, sinus recanalization in 4, development of sinus occlusion in 2, and sinus compression by a newly developed hematoma in 1. CONCLUSION: Spontaneous closures of NCS-DAVFs can occur for both high- and low-risk types. One-third of these closures occur within 3 months.