Purpose: The aim of this study was to examine the relationship between plaque morphology and micro embolic signals (MES) detected by transcranial Doppler ultrasonography (TCD) . Patients and Methods: Clinical investigations were carried out on nine patients who underwent carotid endarterectomy (CEA), including carotid B-mode ultrasound of the carotid artery, perioperative TCD monitoring of the middle cerebral artery, and pathological examination of plaques. Patients were divided into two groups, the hyperechoic and hypoechoic group, according to the carotid Doppler ultrasound findings. TCD monitoring was performed 30 min preoperatively and every 3 days after surgery, and the plaques were examined pathologically for the presence of ulceration. Results: Preoperatively, the rate of detection of MES in ulcerative plaques was likely to be higher than that in non-ulcerative plaques. Intraoperatively, the average number of MES was 3.2 in the nine patients who underwent CEA, and the detection rate of MES was likely to be higher in the hypoechoic group than in the hyperechoic group. Postoperatively, no MES were detected. Conclusion: Surgery should be performed with extreme care, especially in patients with hypoechoic or ulcerative plaques. Perioperative sonology is useful for monitoring the safety of CEA.
