[Complication after Embolization of an AVM with Onyx]

Report on a 34-year-old woman with an arteriovenous malformation (AVM) in the area of the right hippocampus. On the basis of an interdisciplinary indication for step-by-step embolization of the AVM, the first partial embolization with Onyx occurred successfully and without complications. 10 days later, the second partial embolization also turned out well, but during retraction of the microcatheter an exit of Onyx happened into the guiding catheter in spite of continuous aspiration. From there the embolic material was carried off to the carotid T during the control angiography. Despite several efforts of retraction and fragmentation of the dislocated Onyx, finally infarctions with hemiparesis and aphasia resulted in the areas of the terminal branches of the left middle cerebral artery and the left pericallosal artery. However, the expert opinion could not ascertain a malpractice in the treatment of the AVM. Therefore, a suit was not filed against the interventional neuroradiologist.