Arteriovenous malformations (AVM) and arteriovenous 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. Endovascular therapy and radiosurgery became accepted alternatives or adjuncts to surgery. In many instances the choice of the primary therapeutic modality is not clear and arguments can be found for several options. However, microsurgery, endovascular therapy and radiosurgery differ very much with regard to invasiveness, length of stay at the hospital but also residual risk after therapy. The emerging treatment concepts are the object of this book. The result is a unique structured presentation of AVM and AVF therapy.