Endovascular Treatment of Cerebral AVM: Our Experience with Onyx

We have been using Onyx, a non-adhesive liquid polymer, to treat cerebral AVMs endovascularly since 1999. During this time we have treated 45 consecutive, unselected patients. From the outset this product brought about a change in our approach to treating this type of lesion because of the different injection behaviour observed for this material compared with the adhesive Histoacryl that had been employed until then. The object of this article is to assess the results achieved by our team using this new embolic agent, following angiographic and clinical follow-up of cases for a minimum of six months and a maximum of five years (mean: two years). We propose new categories of cerebral AVM based on the expected behaviour of Onyx within the nidus. Our appraisal indicates that we have improved our angiographic results, achieving complete occlusion of the malformation in 22% of cases and over 80-% closure in 69% of cases. The morbimortality rate for the procedure was 18%.