Abstract
We analyze 15 cases with giant/large aneurysms of the internal carotid artery that were treated under intraoperative monitoring of motor evoked potential (MEP). Six cases with symptomatic intracavernous aneurysm were treated with proximal occlusion of the internal carotid artery (ICA) along with use of high flow bypass. In these cases, MEP was monitored for 20-30 minutes after temporary occlusion of the ICA, but no changes were observed. There were no postoperative ischemic complications. In 9 cases with giant/large paraclinoid ICA aneurysm, aneurysms were clipped with the suction decompression method or temporary trapping of the ICA. In 8 cases, MEP amplitudes decreased or flattened after trapping of the ICA for about 5 minutes. However, they recovered after immediate release of the ICA clamp. In all cases, MEP remained normal after the final clipping.
We consider that MEP sensitively detected ischemia of the anterior choroidal artery. Thus, intraoperative MEP monitoring is effective in the treatment of giant/large aneurysms of the ICA.
