A case of cerebral arteriovenous malformation complicated with intracerebral hemorrhage after endovascular embolization

We reported a case of cerebral arteriovenous malformation (AVM), complicated with intracerebral hemorrhage (ICH), after endovascular embolization. A 51-year-old male suffered from intraventricular hemorrhage due to a rupture of an intranidal aneurysm on October 4, 1999. The first embolization procedure for the aneurysm and a part of the nidus was performed with 2-hydroxyethyl methacrylate-metyl methacrylate (HEMA-MMA) and Liquid coil on day 21 after admission. On day 28, a second embolization was carried out for the residual nidus. Although most of the nidus was obliterated, the patient became comatose 10 hours after the second embolization. Computed tomography revealed a massive ICH in the right parietal lobe, and he underwent emergency evacuation of the hematoma. During the surgery, HEMA-MMA was seen in a draining vein. This caused venous stasis. Although the patient gradually improved postoperatively, he became comatose again because of a recurrence of ICH on day 36. Evacuation of the hematoma and removal of the nidus were performed again. The operative specimen showed AVM embolized by HEMA-MMA with non-specific inflammation and partial inflammatory degeneration of the vascular wall. Hemodynamic change such as venous stasis or elevated pressure of the feeding artery seemed to be the cause of the hemorrhage. Multi-staged embolization with longer intervals and intraoperative flow control were regarded as crucial for avoiding delayed hemorrhage.