Curative Embolization of Brain Arteriovenous Malformations with Onyx: Patient Selection, Embolization Technique, and Results

BACKGROUND AND PURPOSE: A new curative embolization technique with Onyx for selected small and medium-sized superficially located brain AVMs was developed, which consists of obliteration of the nidus, including incremental occlusion of the draining veins. We report our first clinical results. MATERIALS AND METHODS: Between June 2008 and July 2011, 24 patients (7 women, 17 men; mean age, 41 years; range, 6-74 years) with AVMs were selected for curative embolization with Onyx. Presentation was hemorrhage in 14 and seizures in 10 patients. AVM location was frontal in 11, occipital in 6, parietal in 4, and temporal in 3. AVM size was a mean of 2.2 cm (median, 2; range, 1-3 cm). RESULTS: Complete angiographic obliteration of the AVM with Onyx in a single session was achieved in all 24 patients. There were no hemorrhagic or ischemic complications (0%; 95% CI, 0%-16.3%), and no new deficits induced by the treatment. Of 14 patients with ruptured AVMs, 1 patient who presented with a large frontal hematoma died shortly after surgical evacuation of the hematoma following complete embolization of a micro-AVM. Follow-up angiography at 3 months in 23 patients demonstrated a small AVM remnant in 1 that was treated with gamma knife radiosurgery. The other 22 AVMs remained completely occluded. CONCLUSIONS: In selected patients with small and medium-sized superficial brain AVMs, as defined in our study, injection of Onyx by using a curative embolization technique in a single session seems to provide a safe and effective alternative to radiosurgery or surgery