症候性大型‐巨大海綿静脈洞部内頚動脈瘤に対する治療戦略―バイパス術・血管内治療の併用タイミングについて―

Abstract

For the treatment of symptomatic large-giant aneurysm in the cavernous portion of the internal carotid artery (ICA), it is often necessary to occlude the ICA with or without extracranial-intracranial (EC-IC) bypass surgery. We report 11 patients with such symptomatic lesions treated between January 2004 and June 2008 by staged endovascular trapping of the aneurysm with detachable coils following selective EC-IC bypass placement. The necessity of the bypass was determined according to neurological conditions and radiological findings during the preoperative balloon test occlusion (BTO) of the ICA. When ischemic symptoms occurred during BTO, high-flow bypass was selected. Otherwise, findings on single-photon emission computed tomography were used for the bypass selection. Following completion of the bypass, dual antiplatelet therapy was induced. Then the confirmative BTO and endovascular ICA occlusion (ICA-O) under local anesthesia were planned several days after the bypass placement. A total of 4 high-flow bypasses with radial artery graft were placed before ICA-O, while 7 patients underwent endovascular ICA-O without bypass surgery. There were no perioperative complications related to the procedures in 10 cases, but 1 developed cerebral infarction 7 days after bypass placement possibly due to distal embolism from intraaneurysmal thrombus. No patients showed postoperative symptoms according to insufficient ipsilateral cerebral blood flow, and cranial nerve palsies improved in all patients. Favorable outcomes can be expected for patients with such aneurysms by staged endovascular ICA-O with selective EC-IC bypass. Although endovascular ICA-O can be safe and useful, understanding of adequate antithrombotic therapy and treatment timing are especially important in cases with bypass placement.