Perioperative microembolism is not associated with cognitive outcome three months after carotid endarterectomy.

OBJECTIVE: To investigate the association between perioperative microembolism and cognitive outcome 3 months after carotid endarterectomy (CEA).

DESIGN: Prospective study.

MATERIALS AND METHODS: Patients were tested 1 day before and 3 months after surgery with neuropsychological tests measuring a wide range of cognitive functions. Number of microemboli was monitored with transcranial Doppler ultrasonography in 58 patients during the operation and in a random subgroup of 27 patients directly following the procedure.

RESULTS: Forty patients (69%) had intraoperative embolism, varying from 1 to 33 isolated microemboli and/or 1 to 11 embolic showers. Postoperative emboli were present in 22 of the 27 patients (81%), ranging from 1 to 142 isolated microemboli. More than 10 microemboli (including showers) were detected in 13 patients (22%) intraoperatively and in 6 patients (22%) postoperatively. Twenty-two patients (38%) showed deterioration in three or more cognitive function variables at 3 months. There were no significant associations between any cognitive change or deterioration score and presence or number of intraoperative and/or postoperative emboli.

CONCLUSIONS: The degree of microembolism during and immediately following CEA is generally small and seems to be of no significance with respect to postoperative cognitive functioning. Future research should include a larger group of patients to allow reliable subgroup analysis.