ANTI-PLATELET DRUGS: CORRELATION BETWEEN PLATELET FUNCTION AND PERIOPERATIVE BLOOD LOSS IN VASCULAR SURGERY Moniaci D*, Iazzolino L*, Renghi A**, Garavoglia M****, Bellomo G***, Pergolini P***, Brustia P* *S.C.D.O. di Chirurgia Vascolare, Ospedale ”Maggiore della Carità”, Novara **S.C.D.U. di Anestesia e Rianimazione I, Ospedale ”Maggiore della Carità”, Novara ***S.C.D.O. di Laboratorio di Analisi Chimico-Cliniche, Ospedale ”Maggiore della Carità”, Novara ****S.C.D.U. di Chirurgia Generale, Ospedale ”Maggiore della Carità”, Novara Introduction In the patient enrolled for Carotid Endarterectomy the anti pla- telet (AP) therapy must continue or has to be introduced in the perioperative period because of the protective effect played both on the carotid postoperative thrombosis and on the coronary complications 1,2,3 . Some Authors even suggest the use of a combined AP therapy, in order to further reduce the risk of postoperative thrombosis 4 . Considering that the balance of an anti-platelet therapy is de- licate and stands between a vascular event and the risk of sur- gical bleeding, the introduction of new tools for assessment of platelet function (Aggregometry and PFA), may suggest impor- tant information to the surgeon, such as the identification of the patients with a perioperative high bleeding risk and the iden- tification of the candidates for the carotid endarterectomy who might undergo combined AP therapy (due to the weak effect of a single therapy). ANTIPLATELET THERAPY Bridge Therapy 6 Aspirin/ dipyridamole: 5 ASA 200 mg: 21 Combined Therapy 6 ASA 100 mg 43 ASA 100 mg ASA 200 mg Thienopyridines Thienopyridines: 28 Direct carotid endarterectomy Direct carotid endarterectomy Bypass Bypass Eversion technique Eversion technique Patch Angioplsty Patch Angioplsty Aspirin/ dipyridamole Bridge Therapy Combined Therapy Materials and Methods A prospective study about all the patients enrolled for Carotid Endarterectomy between October 2008 and May 2009 at the “Vascular and Endovascular Surgery Division”, Novara aimed to evaluate the correlation between AP drug (type/dose), perio- perative bleeding (on the basis of surgeon evaluation) and pla- telet data obtained by PFA and Aggregometry. Results 108 patients were enrolled: 59% were under acetylsalicylic acid therapy, 25% under thienopyridines therapy, 5% under aspirin/ dipyridamole therapy, 6% under bridge therapy (the tempora- ry perioperative substitution of low-molecular-weight heparin or unfractionated heparin in place of warfarin) and 5% under combined therapy. Perioperative outcome: 3 out of 108 patients (2,8%) suffered from minor neurological accidents due to microembolizations, the- re were no hemorragic complication, no cardiac ischemic acci- dents. The PFA and Aggregometry data do not correlate with a longer bleeding time. No AP therapy caused haemostatic difficulties. In the patients with thromboembolic complications neither Aggregometry nor the surgeon’s opinions resulted predictive; we underline that in those patients the PFA data marked a resistance to the ASA the- rapy, but this ASA resistance was sensed also in other patients who had not had such consequences. Conclusions The first outcome of our study is that in CEA surgery AP therapies provide a successful protection against thromboembolic compli- cations without increasing the bleeding time length. The PFA and Aggregometry data do not correlate with surgical bleeding time. If the PFA data are in accordance with the literature 5,6 , those concerning Aggregometry diverge from the literature which instead correlates Aggregometric data and thromboembolic/hemorragic complications. This can be caused by a sample of patients not wide enough, as the complications mentioned above in the samples we studied are small 7 . In order to evaluate the Aggregometric skills about clinical predictability we conclude that further studies on larger samples of pa- tients are essential 8,9 . Bibliography 1 Engelter S, Lyrer P. Antiplatelet therapy for preventing stroke and other vascular events after carotid endarterectomy. Stroke. 2004 May;35(5):1227-8. Epub 2004 Apr 1 2 Chassot PG, Delabays A, Spahn DR. 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Beneficial effects of clopidogrel combined with aspirin in reducing cerebral emboli in patients undergoing carotid endarterectomy. Circulation. 2004 Mar 30;109(12):1476-81. Epub 2004 Mar 8. 5 Gum PA, Kottke-Marchant K, Welsh PA, White J, Topol EJ: A prospective, blinded determination of the natural history of aspirin resistance among stable patients with cardiovascular disease. J Am Coll Cardiol 2003;41:961–965. 6 Chakroun T, Gerotziafas G, Robert F, Lecrubier C, Samama MM, Hatmi M, Elalamy I: In vitro aspirin resistance detected by PFA-100 ■ closure time: pivotal role of plasma von Willebrand factor. Br J Haematol 2004;124:80–85. 7 Casagrande JT, Pike MC, Smith PG: The power function of the ‘exact’ test for comparing two binomial distributions. Appl Stat 1978; 27: 176–80. 8 Karger R, Donner-Banzhoff N, Müller HH, Kretschmer V, Hunik M: Diagnostic performance of the platelet function analyzer (PFA-100) for the detection of disorders of primary haemostasis in patients with a bleeding history – a systemic review and me- taanalysis. Platelets 2007;18:249–260. 9 Toth O, Calatzis A, Penz S, Losonczy H, Siess W: Multiple electrode aggregometry: a new device to measure platelet aggregation in whole blood. Thromb Haemost 2006;96:781–788. email:diegomoniaci@hotmail.com CEA SURGICAL TECHNIQUE XXIV World Congress of the International Union of Angiology April 21 - 25, 2010 Buonos Aires, Argentina View publication stats View publication stats