Ultrasound Turbulence Index during Thromboendarterectomy Predicts Postoperative Cerebral Microembolism

Background: Cerebral microembolic signals (MES) after carotid endarterectomy (CEA) are associated with an increased risk of postoperative stroke. We investigated the relationship of an intraoperatively recorded ultrasound turbulence index (TI) during CEA and the occurrence of MES. Methods: Short-time MES detection was performed on 164 patients (mean age 64 years, 140 males) in the ipsilateral middle cerebral artery within 2 h after CEA. A specialized continuous-wave ultrasound Doppler probe measured the TI within the reconstructed internal carotid artery during surgery. Results: The occurrence of postoperative MES increased significantly with the TI: a TI >26 predicted MES with a sensitivity of 72% and a specificity of 76%. The MES rate and TI were higher in patients operated with the eversion technique than in patients operated with the patch technique (p = 0.005). There was no relationship with preoperative MES, site of surgery or age of patients. Female patients had a higher risk of postoperative MES than males (p = 0.003). Conclusions: Simplified intraoperative Doppler sonography or short-time MES detection after CEA are feasible, and may be helpful for surgical quality control and decision making (e.g. treatment with platelet antagonists).