Abstract
AVM embolization has long been recognized as one of the most useful endovascular procedures. Although it stands out in preoperative situations, its efficacy as a preradiosurgical treatment is not fully accepted. The cause of this discrepancy may be due to errors on both sides : embolization and radiosurgery. An adequate combination strategy with effective embolization to prevent recanalization combined with accurate planning will yield better results. Thanks to the development of catheter and high image resolution the safety of embolization has increased dramatically. Preoperative risk assessment and technical improvements may reduce intraoperative ischemic and hemorrhagic complications ; however, delayed bleeding due to drainage occlusion remains unresolved. This complication may occur even after the radiosurgery. When faced with the life-threatening possibility of drainer occlusion, rapid radical measures should be employed. High grade AVM is considered an untreatable disease according to the recent guideline. However, the resultant size reduction to grade-up cases of Spetzler-Martin grade IV (particularly the S-2 group) with staged embolization or radical treatment by Onyx, will afford an opportunity for treatment, and targeted embolization of the bleeding source for cases with repeated hemorrhage combined with radiosurgery may be an option to maintain the patient QOL.
