[Strategy for the treatment of large-giant aneurysms in the cavernous portion of the internal carotid artery].

The treatment of a large-giant aneurysm in the cavernous portion of an internal carotid artery(ICA)requires occlusion of the ICA, with or without extracranial-intracranial(EC-IC)bypass surgery. Although a balloon occlusion test(BOT)is used to determine the need for bypass surgery and select the bypass type, the criteria are not well established. In this study, we retrospectively analyzed 10 consecutive patients(11 sides)with cavernous large and giant aneurysms treated during the past 8 years. Therapeutic strategies for each patient were selected according to the results of neurological and radiological examinations, and regional cerebral oxygen saturation. A total of 6 high-flow bypasses were placed before ICA occlusions. Three patients had STA-MCA bypasses before ICA occlusions, and two underwent endovascular ICA occlusion without bypass surgery. Favorable outcomes were obtained in all cases with respect to cranial nerve palsy, but one patient had insufficient ipsilateral cerebral blood flow postoperatively, and hemiparesis was revealed. An emergent STA-MCA bypass was performed in this case, which minimized the hemiparesis. Despite radiological evaluation during the BOT procedures, we had one false negative result. This indicates that the BOT requires increased sensitivity and specificity, and that a safety margin should be adopted when determining indications for bypass surgeries.