After a standardized trauma to carotid arteries or femoral veins of hamsters, the antithrombotic effects of two antiplatelet agents (aspirin and the glycoprotein llb/llla antagonist G4120) and two anticoagulants (heparin and the direct thrombin inhibitor rhirudin) were studied in vivo. The thrombus area volume was assessed by image analysis of the transilluminated experimental vessels. Heparin, r-hirudin, and G-4120 demonstrated a dosedependent complete inhibition of arterial and venous thrombosis. In contrast, the antithrombotic effect of aspirin was only partial in both vessel types. A significant correlation between activated partial thromboplastin time (aPTT) at the end of the experiments and the antithrombotic effect was observed with the anticoagulant agents. However, only r-hirudin inhibited thrombus formation at a therapeutical prolongation of aPTT, while heparin required supratherapeutical amounts to achieve the same inhibition. The data confirm that the inhibition of aspirin, heparin, r-hirudin, and G-4120 on the formation of platelet-rich thrombi is independent of the blood flow rate.
Stockmans F, Stassen JM, Vermylen J, Hoylaerts MF, Nystrom A. A technique to investigate microvascular mural thrombus formation in arteries and veins. II. Effects of aspirin, heparin, r-hirudin, and G-4120. Ann Plast Surg 1997;38:63-68