Control of hemorrhage during AVM surgery is one of the key issues to prevent NPPB. Inadequate procedures for hemostasis of feeders and drainers, so-called dilated capillaries and arteries (moja moja blood vessels) that are located on the side facing the normal brain, and inappropriate surgical strategies for intraoperative hemorrhage from these blood vessels are frequently the main cause of the difficulty in achieving hemostatic control. We conclude that it is important to aggressively reduce the occurrence of intraoperative hemorrhage and prevent or minimize the dilatation of abnormal capillaries and arteries due to inappropriate surgical procedures on the basis of the fundamental surgical strategy, i.e., feeder-->nidus-->drainer. Adequately securing the length and adequate coagulation of hemorrhagic blood vessel, employing a skillful bipolar coagulator technique aimed at controlling intraluminal pressure and blood flow on the central side, are believed to be key factors in hemorrhage treatment.