Abstract
Occlusive thrombi formed under high flow shear rates develop very rapidly in arteries and may lead to myocardial infarction or stroke. Rapid platelet accumulation (RPA) and occlusion of platelet-rich thrombi and clot shrinkage have been studied after flow arrest. However, the influence of margination and shear rate on occlusive clot formation is not fully understood yet. In this study, the influence of flow on the growth and shrinkage of a clot is investigated. Whole blood (WB) and platelet-rich plasma (PRP) were perfused at high shear rates (> 3,000 s−1) through two microfluidic systems with a stenotic section under constant pressure. The stenotic section of the two devices are different in stenotic length (1,000 vs 150 μm) and contraction angle of the stenosis (15° vs 80°). In all experiments, the flow chamber occluded in the stenotic section. Besides a significantly increased lag time and decreased RPA rate for PRP compared to WB (p < 0.01), the device with a shorter stenotic section and steeper contraction angle showed a shear-dependent occlusion and lag time for both PRP and WB. This shear-dependent behavior of the platelet aggregate formation might be caused by the stenotic geometry.
Highlights
Occlusive thrombi formed under high flow shear rates develop very rapidly in arteries and may lead to myocardial infarction or stroke
Casa et al.[18] investigated the influence of the von Willebrand factor (vWF) and platelets at various concentrations. They reported that vWF is the primary mediator of high shear thrombosis and hypothesized that vWF stored in α-granules of platelets may be critical for occlusive thrombus formation
We report high shear rate thrombus formation in Casa’s and Van Rooij’s flow chamber
Summary
Occlusive thrombi formed under high flow shear rates develop very rapidly in arteries and may lead to myocardial infarction or stroke. Besides a significantly increased lag time and decreased RPA rate for PRP compared to WB (p < 0.01), the device with a shorter stenotic section and steeper contraction angle showed a shear-dependent occlusion and lag time for both PRP and WB This sheardependent behavior of the platelet aggregate formation might be caused by the stenotic geometry. The objective of this study is to investigate the influence of the shear rate, platelet margination and the hemodynamics on platelet aggregate growth and shrinkage using two microfluidic flow chamber with a different geometry. Casa et al.[18] investigated the influence of the vWF and platelets at various concentrations They reported that vWF is the primary mediator of high shear thrombosis and hypothesized that vWF stored in α-granules of platelets may be critical for occlusive thrombus formation. They found a higher clot contractile force and a higher platelet density for higher shear rates (3–1,500 s −1)
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