Multimodality therapy for cerebral arteriovenous malformations focusing on endovascular therapy: Strategy and technical aspects

Objective : In treating cerebral arteriovenous malformations (AVM), the efficacy of presurgical or preradiosurgical embolization is still considered suspicious, mainly due to the high incidence of the endovascular procedure. In this article, the efficacy of presurgical as well as preradiosurgical embolizaton is described. Methods : During January 2005 to July 2007, fifty patients with AVMs were treated in our institute and thirty-nine patients were treated by means of "multimodality" therapy including preoperative or preradiosurgical embolization. Among them, twelve patients received preoperative endovascular procedures, whereas seven patients underwent preradiosurgical embolization. As to the endovascular procedures, n-butyl cyanoacrylate (NBCA) was used as the embolic material. The interval between endovascular therapy and surgery/radiosurgery was one to seven days except for one case (mean 4.4 days). Results : One session was required for the endovascular procedures in 14 patients, two in three patients and, four in one patient. There was no permanent morbidity or mortality related to either modality. The modified Rankin Scale Score of the patients treated by multimodality therapy was 0 in eleven, 1 in five, and 2 in three. Conclusion : The main role of presurgical embolization is the occlusion of feeders which seem surgically difficult to access ; meanwhile the role of preradiosurgical embolization is AVM volume reduction by intranidal embolization. To achieve effective embolization for AVMs, a thorough discussion among the neurovascular surgeon, radiologist and neuroendovascular physician is mandatory to maintain a high success rate in each modality.