To predict the patency of the circle of Willis and cerebral ischemia during carotid artery surgery (ligation, resection, revascularization) is of utmost importance both for the surgeons and the patients. Many methods have been proposed in the literature as simple and accurate means of evaluating the adequacy of collateral hemispheric blood flow to compensate for a potentially resectable carotid artery, including Matas test, DSA, intraoperative measurement of stump pressure or back pressure, preoperative and intraoperative EEG monitoring, ocular plethysmograph (OPG), temporary balloon occlusion (TBO) alone or with single photon emission computerized tomography (SPECT), xenon-enhanced computed tomography cerebral blood flow (Xe/CT CBF), and transcranial color Doppler (TCD). However, there is no single method as accurate and reliable as expected till now. This paper evaluated the merits and flaws of each method. Our review and clinical studies showed that the combination of preoperative TBO and SPECT cerebral blood flow imaging significantly increases the safety of ICA /CCA resection, which can be used routinely to predict the patients’ tolerance for carotid artery sacrifice without developing neurologic deficits. Supported by Research Fund of the Ministry of Public Health (Grant No.96-1-340) and Sustentation Plan for Excellent Academic Leader of Shanghai Municipality (Grant No.96XD14013).
