脳動静脈奇形の塞栓術におけるｐｉｔｆａｌｌとその対策

Abstract

As the embolization of AVMs is often an adjuvant therapy combined with surgical extirpation or radiosurgery, the goal is to optimize the outcome of the following procedure. As the natural history of AVMs predicts a relatively low rate of neurological injury, the combined therapeutic modalities should have a low complication rate. We report the perisurgical complications of 66 AVMs and discuss techniques to avoid complications. Of the 66 patients treated with endovascular embolization, 14 subsequently underwent surgical resection and 43 had radiosurgery. Four patients obtained total occlusion of their AVM by embolization alone and required no further treatment. In 48 patients, more than 70% of the nidus was occluded with embolization. We observed 3 permanent and 9 temporary complications. Four complications occurred immediately after embolization, due to overembolization or thromboembolism. Seven delayed complications occurred, possibly due to retrograde thrombosis or a chemical reaction to the glue. In 4 of the 14 cases without AVM obliteration following embolization and radiosurgery, meningeal feeders developed or recanalized after the treatment with absorbable particles. We recommend embolization prior to radiosurgery to treat all fistulous and meningeal feeders and packing of the nidus with non-absorbable embolic materials. In 10 cases, repeat embolization achieved further nidus reduction prior ro repeat radiosurgery. Intranidal aneurysms that pose a high risk of bleeding were also embolized. To avoid complications with embolization, the AVM angioarchitecture, hemodynamics and functional location should be well recognized. Complications can be reduced with preoperative functional imaging, superselective angiograms, appropriate selection of embolic materials, and appropriate selection of embolization targets. The priority of vessels to be embolized is dictated by the subsequent treatment. Agressive embolization of high-risk vessels or those that will cause abrupt hemodynamic changes should be avoided.