Outcome of Endovascular Treatment of Cerebral Arteriovenous Malformations with Ethylene Vinyl Alcohol Coploymer

Abstract

Cerebral AVMs are very rare lesions, and this rarity contributes to the difficulty of treating them. There is no consensus concerning the method of treatment to be chosen among neurosurgery, radiosurgery or embolization. Onyx embolization could serve as a curative option with accepted morbidity and mortality. The introduction of Onyx and of catheters with detachable tips has no doubt increased the rate of endovascular occlusion, and decreased the risks associated with treatment in our experience. Understanding the angioarchitectural characteristics of the treated AVM could help in better differentiation between lesions suitable for curative Onyx embolization, with fewer treated feeders and high occlusion rate and those non-suitable for curative embolization. Good selection of intranidal catheter tip position with slow, controlled injections that avoid the draining veins can minimize the procedural risk even in eloquent locations. We think that curative embolization should be offered for selected cases based on certain criteria that need further research to develop grading system in structuring the risk–benefit assessment of obliterative embolization of a particular AVM. For the cases that are not fulfilling these criteria, embolization should be offered as preparing step for other modality of treatment. In our experience, for curative embolization, the AVM should be small sized (< 3 cm), supplied by one vascular territory, with feeders that can tolerate reflux up to 2–3 cm, with clear proximal parts of the draining veins, and not located in deep structures.