Selective Shunting Based on Dual Monitoring with Electroencephalography and Stump Pressure for Carotid Endarterectomy

PURPOSE: The aim of this study is to analyze postoperative outcomes for carotid endarterectomy (CEA) in addition to the preoperative clinical characteristics related to selective shunting based on dual monitoring with stump pressure (SP) and electroencephalography (EEG). MATERIALS AND METHODS: We retrospectively reviewed medical records of 70 patients who underwent CEA from March 2010 to December 2017. CEA was performed under general anesthesia and selective shunting was done if the SP was lower than 35 mmHg regardless of EEG or if intraoperative EEG showed any changes different from preoperative one regardless of SP. RESULTS: There was no postoperative 30-day adjusted mortality or adverse cardiac events. Three patients (4.3%) had postoperative minor stroke finally reaching pre-operative neurologic status at the time of discharge. Twenty-six patients (37.1%) used shunting and severe contralateral internal carotid stenosis or occlusion was related to shunting (P < 0.010). There were larger number of symptomatic patients in shunt group in spite of no statistical significance (P=0.116). CONCLUSION: Perioperative stroke rate was 4.3% for CEA under general anesthesia based on dual intraoperative monitoring with SP and EEG. There was no 30-day adjusted mortality and adverse cardiac event. Severe stenosis or occlusion of contralateral internal carotid artery is related to shunting (P < 0.010).

Intraoperative Neurophysiologic Monitoring: Basic Principles and Recent Update

The recent developments of new devices and advances in anesthesiology have greatly improved the utility and accuracy of intraoperative neurophysiological monitoring (IOM). Herein, we review the basic principles of the electrophysiological methods employed under IOM in the operating room. These include motor evoked potentials, somatosensory evoked potentials, electroencephalography, electromyography, brainstem auditory evoked potentials, and visual evoked potentials. Most of these techniques have certain limitations and their utility is still being debated. In this review, we also discuss the optimal stimulation/recording method for each of these modalities during individual surgeries as well as the diverse criteria for alarm signs.