Neuromonitoring of perioperative microembolization and its association with postoperative stroke after carotid endarterectomy

Abstract Purpose This study aims to assess whether perioperative microembolization can identify patients at risk for postoperative stroke. Methods A total of 257 carotid endarterectomy procedures in 254 patients were analyzed (154 symptomatic, 103 asymptomatic). Neuromonitoring, combining transcranial Doppler ultrasonography and continuous electroencephalography, was utilized to evaluate cerebral perfusion and detect microembolic signals (MES). Monitoring covered the entire intraoperative phase and a standardized 20-minute postoperative observation window. Results Postoperative stroke occurred in seven patients, six of whom were symptomatic prior to the procedure. In exploratory penalized regression analyses, higher postoperative MES counts (OR 1.02 per MES, 95% CI 1.01–1.04; p < 0.001) and an intraoperative burden of ≥ 10 MES (OR 6.06, 95% CI 1.40–34.78; p = 0.016) were associated with postoperative stroke. Symptomatic patients exhibited a significantly higher embolic burden (6.7 ± 13.3 vs. 2.2 ± 5.0, p = 0.004). Conclusion Beyond its role in guiding selective shunting, transcranial Doppler monitors the occurrence of microembolization, which could serve as a potential indicator of perioperative stroke. In this exploratory analysis, both an intraoperative burden of 10 or more MES and sustained postoperative microembolization were associated with postoperative stroke. Given the low number of events, these findings are hypothesis-generating and require prospective validation before they can guide perioperative management.