Perioperative microemboli and platelet aggregation in patients undergoing carotid endarterectomy.
In carotid endarterectomy (CEA) patients, platelet aggregation is increased despite heparinization. We investigated whether this phenomenon correlates with the occurrence of perioperative microemboli. Of 27 CEA patients, 18 (67%) used aspirin and 9 also used clopidogrel. Blood was collected at multiple time points before, during, and after CEA. Platelet aggregation and P-selectin expression were determined. Transcranial Doppler monitoring was used to measure microemboli. Platelet aggregation showed a significant increase 5 minutes postheparinization compared with preheparinization (19.7 +/- 2.8% vs 8.9 +/- 0.9% in the aspirin group and 22.5 +/- 4.4% vs 8.7 +/- 1.2% in the clopidogrel group; p < .01 and p < .05, respectively). P-selectin expression showed a tendency to increase postheparinization in both groups (p = .07 and p = .09, respectively). The number of microemboli ranged from 0 to 50. Clopidogrel patients displayed fewer microemboli than aspirin patients (4.1 +/- 2.3 vs 17.6 +/- 18.2; p < .01). Patients with a high number of microemboli displayed had a tendency toward higher baseline platelet aggregation than patients with a low number of microemboli (p = .08). In conclusion, platelet aggregation is transiently increased during CEA despite the administration of antiplatelet agents. Clopidogrel is associated with a decreased number of perioperative microemboli. The exact relationships between these findings, postoperative microemboli formation, and the risk for thromboembolic complications after CEA remain to be determined.
Vogten
J Mathys
JM
Department of Vascular Surgery, St Antonius Hospital, Nieuwegein, The Netherlands. jmvogten@hotmail.com
Gerritsen
Wim B M
WB
Ackerstaff
Rob G A
RG
van Dongen
Eric P
EP
de Vries
Jean-Paul P M
JP
D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D000077144:Clopidogrel; D004359:Drug Therapy, Combination; D004617:Embolism / Q000175:diagnosis; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood / Q000502:physiology; D010974:Platelet Aggregation / Q000187:drug effects* / Q000502:physiology; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011446:Prospective Studies; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods
D000925:Anticoagulants; D015415:Biomarkers; D019007:P-Selectin; D010975:Platelet Aggregation Inhibitors; D006493:Heparin; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin