CAR 2. Multimodal Neurophysiologic Monitoring Reduces Shunt Incidence During Carotid Endarterectomy

Abstract

The use of a shunt during carotid surgery is controversial. Good results have been found in the literature both with routine use of a shunt and with no shunt during general anesthesia. Other studies report similar results with selective shunting with the support of cerebral monitors. Different experiences are found in the literature with transcranial Doppler (TCD), electroencephalography (EEG), stump pressure (SP), and somatosensory evoked potentials (SSEP). To the best of our knowledge, there are no controlled studies to document the relative efficacy of these techniques. The purpose of this study was to describe the results of our experience using multimodal neurophysiologic monitoring by EEG with SSEP for cerebral monitoring during carotid surgery. We conducted a retrospective analysis of patients treated with carotid endarterectomy in our unit in the last 2 years. We used several forms of cerebral monitoring. Until 2017, we preferred SP with TCD or, if that was not available, EEG. Since 2017, we introduced EEG with SSEP, always in association with SP. We analyzed those two groups of patients before and after introduction of EEG with SSEP. From January 2016 to December 2018, we performed 156 carotid revascularizations. In the first group of 93 patients treated under combined SP and TCD (or EEG), we observed one stroke (1.1%) and two transient ischemic attacks (2.1%); we selectively used a shunt in 21 cases (22.5%). In the second group of 63 patients who had SP and EEG with SSEP monitoring, we observed one stroke (1.5%) and two transient ischemic attacks (3.1%); a shunt was necessary in 12 cases (12.9%). Combination of different methods allows minimal shunt use during carotid surgery. EEG with SSEP monitoring during carotid surgery has been demonstrated to be safe and sensitive for prediction of cerebral ischemia during carotid clamping. In our experience, EEG with SSEP monitoring represents an effective parameter to indicate shunting.