Abstract TP83: Benefit Of Multimodal Intraoperative Neuromonitoring Techniques During Carotid Procedures

Abstract

Background: Carotid intervention is done for reduction of stroke risk. Intraoperative neuromonitoring (IOM), including electroencephalography (EEG), somatosensory evoked potential (SSEP), and cerebral oximetry/near-infrared spectroscopy (NIRS) may be used to guide operative decision-making and minimize the risk of perioperative complications. The utility of combining IOM methods is unclear. Therefore, we sought to investigate the value of multimodal IOM for carotid interventions. Methods: A retrospective review of all patients undergoing carotid intervention from January 1, 2012 to December 31, 2019 at a single academic medical center was done. Patients with acute stroke undergoing catheter directed thrombectomy were excluded. Data collected included: patient demographics, IOM parameters, surgical intervention with endpoints of 30-day post-operative complications. Surrogate end-points of IOM change and intraoperative hemodynamic interventions were also assessed. Efficacy and diagnostic value of each IOM modality alone, and in combination, were assessed using multivariable logistic regression. Results: 409 carotid interventions in 311 patients meeting inclusion criteria were identified. Patients were 63.3% male, 36.7% female, 83.4% white, 7.1% Hispanic, and 5.9% other. 162(39.6%) interventions were performed for ipsilateral symptoms including 111(27.1%) ipsilateral stroke, 91(22.3%) TIA. Use of a single versus multiple IOM modalities was not associated with a reduction in post-operative neurologic events. Changes in SSEP demonstrated a 2.97 odds ratio for predicting neurologic adverse events (AE), though this was not statistically significant. Conclusion: IOM changes were associated with an increase in AEs but IOM impact on intraoperative changes in surgical plans were infrequent. It is unclear whether IOM had a significant impact on procedural modifications though this may reflect an underpowered sample size. The low impact of IOM on outcome raises the question of cost-effectiveness of these techniques in reducing intraoperative complications from carotid procedures.