A Case of Brainstem Arteriovenous Malformation Cured by Transvenous Embolization with Onyx

Objective: We report a case of ruptured brain stem arteriovenous malformation that was successfully treated by transvenous embolization in addition to transarterial embolization using Onyx. Case Presentation: A 61-year-old woman was admitted because of consciousness disorder following sudden-onset headache. CT revealed brain stem hemorrhage and MRI revealed abnormal vessels around the brainstem. Cerebral arteriovenous malformation on the right side of the pons was identified from an angiography. Her consciousness gradually improved from conservative treatment. Thereafter, endovascular treatment was performed. First, transarterial embolization with Onyx was performed to reduce the nidus as much as possible. Then, transvenous embolization for the remaining nidus was performed to completely embolize the cerebral arteriovenous malformation. No new neurological deficits were observed after treatment and no recurrence was noted on follow-up angiography 1 month after treatment. Conclusion: We treated the brainstem arteriovenous malformation using a combination of transvenous and transarterial embolizations. In suitable cases, transvenous embolization can be an alternative treatment for deep-seated cerebral arteriovenous malformations that are difficult to treat by transarterial embolization or direct surgery.