title: Perioperative microemboli and platelet aggregation in patients undergoing carotid endarterectomy.
abstract: 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.
authors.affiliation: Department of Vascular Surgery, St Antonius Hospital, Nieuwegein, The Netherlands. jmvogten@hotmail.com
authors.forename: J Mathys
authors.initials: JM
authors.lastname: Vogten
authors.forename: Wim B M
authors.initials: WB
authors.lastname: Gerritsen
authors.forename: Rob G A
authors.initials: RG
authors.lastname: Ackerstaff
authors.forename: Eric P
authors.initials: EP
authors.lastname: van Dongen
authors.forename: Jean-Paul P M
authors.initials: JP
authors.lastname: de Vries
mesh_terms: 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
chemical_list: D000925:Anticoagulants; D015415:Biomarkers; D019007:P-Selectin; D010975:Platelet Aggregation Inhibitors; D006493:Heparin; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin