The limitations and risks of transarterial Onyx injections in the treatment of grade I and II DAVFs

Abstract

Embolization of grade III-V intracranial DAVFs using Onyx is feasible with promising results, indicating stability at the time of mid-term follow-up. This article is to evaluate the role of transarterial Onyx embolization in the treatment of grade I and II intracranial dural arteriovenous fistulas (DAVFs), including its limitations and risks. We retrospectively studied consecutive 26 patients (8 women and 18 men) treated for an grade I and II intracranial DAVF since 2006 in whom a transarterial approach was attempted with Onyx-18 embolization. There were 18 transverse-sigmoid sinus, 4 cavernous sinus, 2 superior sagittal sinus, 1 inferior petrosal sinus and 1 intradiploic fistulas. Five fistulas were Type I, 8 were Type IIa, and 13 were Type IIa+b, according to the Cognard classification. The mean clinical follow-up period was 15.6 months. Anatomic cure was proven in 13 patients (50%) and clinical cure was obtained in 17 cases (65.4%). These 13 cures were achieved after a single procedure. All these 13 patients underwent a follow-up angiography, which has confirmed the complete cure. Partial occlusion was obtained in 13 patients. Complications were as follows: 2 cardiac Onyx migration, 2 reflexive bradyarrythmia, 1 transient visual hallucination, 2 transient fifth nerve palsies and 1 permanent seventh nerve palsy in inferior petrosal sinus DAVF. Based on this experience, grade I and II intracranial DAVFs may be treated with transarterial Onyx embolization to reduce the shunted blood flow and to facilitate subsequent transvenous embolization or surgery.