Hemorrhage risk after partial endovascular NBCA and ONYX embolization for brain arteriovenous malformation

To estimate for hemorrhage risk of partially endovascularly embolized brain arteriovenous malformation (BAVM).

We retrospectively reviewed 147 consecutive patients with BAVM-treated mainly with endovascular N-butyl cyanoacrylate (NBCA) and ONYX embolization. In Kaplan-Meier survival analysis, the index date was the dated of initial endovascular embolization; cases were censored at time of subsequent intracranial hemorrhage (ICH), or loss to follow-up, and multivariate proportional-hazards regression models included age of presentation (≤30 years old), clinical presentations, and other potential confounders.

We reviewed 147 patients with BAVM (58.8% male; mean age±SD at treatment: 27.5±11.1 years) treated with endovascular embolization. One hundred and forty-four NBCA and 76 ONYX embolizations were performed. Complete obliteration of BAVMs was achieved in 29 patients (19.7%). Thirty-two (21.8%) patients were treated with additional Gamma-knife radiosurgery. During 499.5 years of follow-up, 15 partially treated patients suffered a further hemorrhage, which caused four deaths. The crude annual risk of hemorrhage was 3.0% and the annual death rate was 0.8%. Among partially treated patients with hemorrhage at initial presentation, the risk of hemorrhage was 3.8%, while the risk of hemorrhage for patients without hemorrhage at initial presentation was 2.5%. The annual rate of subsequent hemorrhage was 2.6% for non-ICH and 4.2% for ICH in the partial NBCA embolization group compared with 2.4% for non-ICH and 2.4% for ICH in the partial ONYX embolization group.

The effect of partial AVM embolization with liquid embolic agents may still be unclear as for risk reduction of annual hemorrhage rate of cerebral AVM.