Impact of General Versus Local Anesthesia on Early Postoperative Cognitive Dysfunction Following Carotid Endarterectomy: GALA Study Subgroup Analysis

Abstract

The aim of this study was to compare the influence of either general (GA) or local (LA) anesthesia on the postoperative neurocognitive outcome in patients undergoing carotid endarterectomy (CEA) in a randomized study. Therefore, we performed a subgroup analysis of the multicenter GALA study. A total of 40 patients were enrolled and randomized to receive either LA (n = 17) or GA (n = 23) anesthesia. The indication for intraoperative shunting was based on the intraoperative cognitive performance in the LA group and on the clinical experience of the surgeon in the GA group. Outcome measurements included patient performance on a neuropsychological Trail Making Test, evaluation of patients mood using the self-report inventory BSKE, and serum levels of the neurobiochemical marker S100ß. The data were analyzed for each variable using a t-test and were presented as the mean (SD). Differences in shunt frequency were analyzed performing a chi-squared test. Group differences in the Trail Making Test, BSKE evaluation, and S100ß concentrations were derived from the analyses of covariances with repeated measurements using preoperative values as covariates. Compared to baseline, the S100ß concentrations increased significantly in the GA group [0.086 (0.038) vs. 0.061 (0.024) μg/l; p < 0.001] before unclamping of the carotid artery, whereas there were no changes in the LA group [0.068 (0.024) μg/l, p = 0.09 vs. 0.061 (0.021) μg/l, p = 0.09). Furthermore, we detected significant group differences after surgical intervention (GA 0.087 (0.031) μg/l; LA 0.06 (0.021) μg/l; p = 0.006). The postoperative neurocognitive performance in the Trail Making Test decreased significantly in the GA group, whereas there were no significant changes in the LA group. The self-report inventory BSKE evaluation revealed no significant group differences. We concluded that performing local anesthesia in patients undergoing CEA positively influenced early postoperative neurocognitive outcomes. Significant group differences in postoperative S100ß concentrations confirmed the beneficial effect of local anesthesia.