2012 Volume 40 Issue 6 Pages 414-419
We treated 38 cases of the internal carotid artery (IC) aneurysms between April 2007 and December 2011. Twenty-seven cases were IC-posterior communicating artery (PCoA) aneurysms, eight cases were IC-anterior choroidal artery (AChA) aneurysms and three cases were IC anterior wall aneurysms. The intraoperative motor evoked potentials (MEPs) and fluorescein cerebral angiography (FAG) were monitored in these cases, and we estimated the cause and measures of blood flow insufficiency in the anterior choroidal artery. In five patients, disappearance or decrease of MEP amplitude was observed. In three patients with AChA aneurysm, transient MEP changes was caused by stenosis or occlusion of the AChA by the clip, and MEP recovered to the control level after the clip reposition. Postoperative deficits were not observed. In two patients with PCoA aneurysm, the vasospasm of AChA occurred due to mechanical stimulation to AChA during dissection from aneurysm, and MEP disappeared. By application of papaverine hydrochloride to the AChA, MEP recovered in a patient and postoperative neurological deficits did not occur. In the other patient, patency of AChA was observed by FAG but MEP was not recovered and motor deficits were observed. In clip application of the IC-AChA aneurysm, although patency of the AChA was microscopically apparent, the occlusion of the true inside of the AChA did not occur. We should apply clips to preserve the AChA in reference to MEP findings.
Intraoperative MEP monitoring and FAG are useful to prevent ischemic complication by occlusion of the AChA during IC aneurysm surgery.
