Two-step presurgical endovascular treatment of five arteriovenous malformations partially fed by single vessels en passage

PURPOSE To describe a method for the preoperative embolization of arteriovenous mal formations (AVM) containing vessels en passage (VeP). First, before emboliz ation of the primary AVM, the distal portion of the VeP beyond the AVM,whic h supplies the parenchymal compartment, is blocked through placement of an endovascular ligature (fibered coils). This protects the post lesional pare nchymal tissue and isolates malformational compartments before embolization . Thus the proximal AVM-supplying segment of the VeP can be safely embolize d. PATIENTS AND METHODS Five of 204 AVM patients admitted for preoperative embolization between 198 9 and 1997 fulfilled the following treatment criteria for the placement of an endovascular ligature in a VeP before embolization: 1. The diameter of t he distal portion of the VeP behind the AVM was large whereas the parenchym al blush was poor; 2. The VeP fed a large portion of the AVM; 3. The VeP wa s judged to be accessible only late in the surgical procedure; 4. The VeP a nd its off branches were an integral part of the AVM periphery and thus not suitable for microdissection. RESULTS in all five cases the leptomeningeal collateral perfusion (the arterial sup ply to parenchymal brain areas) served to supply brain areas distal to the AVM after primary blockage of a VeP by endovascular ligature with fibered c oils. Embolization and complete surgical dissection of the AVM was then ach ieved in all cases. No neurological deficits occurred. CONCLUSION Experience with our five cases indicates that a preparatory endovascular li gature of a VeP between parenchyma and the malformational compartment follo wed by embolization of the AVM can serve as an alternative to open surgical dissection of a vessel en passage and that it safely allows effective preo perative embolization. (C) 1999 by Elsevier Science Inc.