Cerebral Abscess After Onyx Embolization of an Arteriovenous Malformation

Background: Endovascular embolization is being increasingly used to treat cerebral arteriovenous malformations. Common complications associated with embolization include intracranial hemorrhage and ischemic stroke; intracranial infections seldomly occur and are even less frequently reported. Although abscess formation after embolization is exceedingly rare, it is a serious condition that warrants immediate attention.

Case description: This 53-year-old male with a ruptured left temporal-occipital arteriovenous malformation. He underwent uncomplicated 2-stage embolization with Onyx and was discharged. Five weeks after embolization, he returned to the hospital with worsening aphasia and contralateral hemiparesis, and a cerebral abscess was detected at the site of embolization. Bacterial cultures were positive for Escherichia coli, and he was treated successfully with surgical excision of the abscess and Onyx material, followed by long-term antibiotics.

Conclusions: Although rare, formation of an intracranial abscess after endovascular embolization is a potential complication in the treatment of arteriovenous malformations.