Subarachnoid hemorrhage during arteriovenous malformation embolization as a result of vessel wall "sandblasting".

Preoperative selective particulate embolization of arteriovenous malformations can make subsequent surgical resection of such lesions safer for the patient and easier for the surgeon. Nevertheless, embolization carries intrinsic risks, which include subarachnoid hemorrhage. We report two cases of subarachnoid hemorrhage during particulate embolization that we think was attributable to catheter positioning near a vessel curve and subsequent denudation of the vessel wall to the degree that hemorrhage was induced.