Transarterial Embolization of Intracranial Dural Arteriovenous Fistulas with Direct Cortical Venous Drainage using Ethylene Vinyl Alcohol Copolymer (Onyx)

Purpose: This communication concerns the new possibilities and technical aspects of using ethylene vinyl alcohol copolymer ( Onyx, EVAC) for endovascular treatment of intracranial dural arteriovenous fistulas with direct cortical venous drainage (DAVF-CVs). Patients and Methods: Five patients with symptomatic DAVF-CVs were treated primarily with transarterial embolization using Onyx. Results: All patients had complete obliteration of their DAVFs with a single Onyx injection that resulted in passage of embolic agent to the draining vein. One asymptomatic technical adverse event occurred ( a broken microcatheter on retrieval). On clinical follow-up ( mean 12.6 months, range 1-27 months), two patients with intracranial hemorrhage and one patient with cerebellar symptoms improved significantly after treatment, with residual symptoms that did not affect independence. One patient had remission of tinnitus and headache but developed seizures, and one patient was asymptomatic. Imaging follow-up ( mean 4 months, range 1-7 months) did not show any revascularization. Conclusion: Embolization with Onyx represents a significant improvement in the endovascular treatment of DAVF-CVs. Cases that would not be effectively treated with cyanoacrylate or particles can be cured by embolization alone.