An absence of platelet VWF prevents occlusive thrombus formation in the modified Folts arterial stenosis model. (A) Mean blood flow through the carotid artery was reduced to 50% by making stenosis and subsequently crush injury was induced. WT mice consistently formed an occlusive thrombus in response to the stenosis and crush injury. In contrast, there was no occlusive thrombus formation in the carotid artery of the Nbeal2^−/− mouse (n = 7, bar shows ± standard error of the mean [SEM]; P < .0001). (B) WT mice formed occlusive thrombi at an average time of 330 seconds after deendothelization of the stenosed vessel. Nbeal2^−/− mice were unable to form occlusive thrombi in vivo (n = 7, bar shows ± SEM; P < .0005). (C) Representative macroscopic images of the gross anatomy of an excised carotid artery from WT and Nbeal2^−/− mice. The WT carotid features a prominent clot (arrows) within the longitudinal arterial lumen (outlined) suggesting the presence of an occlusion. There is a clear absence of occlusive matter within the lumen of the Nbeal2 carotid (outlined). (D) Carstairs histological staining revealed that the WT thrombi were primarily composed of platelets (blue material in the lumen).