Chapter 48 Carotid endarterectomy monitoring

Publisher Summary Carotid endarterectomy neuromonitoring is performed to identify those patients who need a shunt during carotid cross-clamping (CCC). Neuromonitoring can be performed with somatosensory evoked potentials (SEP). This chapter discusses the relationships between pre and intraoperative variables and intraoperative SEP features. Population study presented in the chapter confirms that there are pre and intraoperative differences among the different groups of patients. Data from the study demonstrates that the strategy of SEP monitoring is an efficient and reliable method to select patients who need to be shunted in carotid endarterectomy. The degree of ipsilateral stenosis was lower and the degree of contralateral stenosis was higher in patients in whom intraoperative monitoring revealed SEP alterations that indicated shunting. This could forecast that a lower degree of ipsilateral stenosis implies a higher blood steal after CCC and a higher degree of contralateral stenosis implies less efficient suppleances through the polygon of Willis. There were significantly lower stump pressure and a higher gradient immediately after CCC. A similar trend was observed in patients who developed mild alterations, because of a drop in blood pressure. Another finding was that the mean pre-induction blood pressure was higher in patients who developed blood-pressure related alterations outside the cross-clamping period. This suggests that these patients actually need a higher blood pressure to overcome the obstacle and questions the opportunity of operating on them under low pressure regimen. None of the pre and intraoperative parameters are sufficient in isolation to predict the necessity to shunt in individuals under the population study.