Possible determinants of early microembolism after carotid endarterectomy.
OBJECTIVE
High numbers of microembolic signals (MES) have been associated with increased risk of postoperative stroke after carotid endarterectomy (CEA). We sought to identify factors predictive of postoperative MES.


METHODS
Transcranial Doppler monitoring of the ipsilateral middle cerebral artery for MES was performed for 30 minutes during the first postoperative hour in sequential patients undergoing CEA. Stepwise binomial logistic regression analysis was performed to identify preoperative and intraoperative variables that predicted the occurrence of postoperative MES.


RESULTS
We studied 141 patients (mean age, 69 years); 102 (72%) were male, and 69 (49%) had at least 1 MES (range, 1 to 118) detected in the first postoperative hour. The risk of postoperative MES was greater in women (P=0.027), patients not receiving antiplatelet therapy (P=0.033), and patients undergoing left-sided CEA (P=0.049). Other variables such as residual stenosis seen on completion angiography and operative technique were not associated with postoperative MES.


CONCLUSIONS
Postoperative MES were most likely in women, patients not receiving preoperative antiplatelet therapy, and patients who had a left CEA. Microembolism might explain why these same factors are associated with higher rates of perioperative stroke.
Stork
Jacinda L
JL
National Stroke Research Institute, Austin and Repatriation Medical Centre, West Heidelberg, Victoria 3081, Australia.
Levi
Christopher R
CR
Chambers
Brian R
BR
Abbott
Anne L
AL
Donnan
Geoffrey A
GA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003911:Dextrans / Q000627:therapeutic use; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000517:prevention & control; D007432:Intraoperative Period; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D008991:Monitoring, Physiologic; D015999:Multivariate Analysis; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011184:Postoperative Period; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000209:etiology* / Q000517:prevention & control; D017585:Ultrasonography, Doppler, Transcranial
D003911:Dextrans; D010975:Platelet Aggregation Inhibitors