Onyx embolization as a first line treatment for intracranial dural arteriovenous fistulas with cortical venous reflux.

Purpose: Our purpose was to present our experience regarding embolization of intracranial dural arteriovenous fistulas (DAVFs) with cortical venous reflux using Onyx, a non-adhesive liquid embolic agent.

Materials And Methods: From January 2006 to December 2007, 16 patients (12 men and 4 women) with a mean age of 61 years (range 42 - 78) with an intracranial DAVF with cortical venous reflux underwent at least one transarterial embolization using Onyx. According to the Cognard classification, 2 lesions were grade V, 5 were grade IV, 6 were grade III, 2 were grade IIa+b, and 1 was grade IIb. The clinical presentation included 5 hemorrhagic deficits, 10 non-hemorrhagic manifestations, and 1 patient was asymptomatic.

Results: Twenty-four embolization sessions were performed in 16 patients with an average of 3 arterial feeders (range 1 - 9) embolized per DAVF. Immediately after embolization, complete occlusion was achieved in 9/16 (56%) patients after the first session. Further postembolization surgical treatment was performed in 3 patients. Partial reperfusion occurred in 1 patient at the time of mean follow-up of 3.7 months (range 0 - 12). Treatment has been completed for 11/16 patients with angiographic cure in 10/11 (91%). An infratentorial bleeding complication related to embolization occurred in one patient with temporary worsening of the patient's gait disturbance. At the time of mean clinical follow-up of 4.5 months (range 0 - 12), no procedure-related permanent morbidity was added to our cohort.

Conclusion: According to our experience, embolization of intracranial DAVFs with cortical venous drainage using Onyx is feasible with promising results, indicating stability at the time of mid-term follow-up. In very complex DAVFs additional embolization material might be necessary, and in some cases surgery is warranted.