Arteriovenous malformations (AVM) and fistulas (AVF) differ from all other pathology affecting the central nervous system by their high-flow arteriovenous shunts. Permanent occlusion of these shunts is the essence and the challenge of therapy. Much progress has been made since the first neurosurgical efforts to deal with these problems. Endovascular therapy and radiosurgery became accepted alternatives or adjuncts to surgery. In many instances the choice of the primary therapeutic modality...