Captured agglomerates (ie, platelet aggregates) show 3 distinct morphologies primarily controlled by VWF length. (A) The platelet aggregate morphology depends on the VWF length and concentration. Three states, namely cluster state, elongated state, and loose state, are shown in the figure as a primary function of VWF length. (B) The top view of aggregate morphology observed in silico (noted in the colored boxes) for selective VWF conditions as denoted in panel A. Similar aggregate morphology observed in vitro is depicted side by side for comparison. For all 3 examples, the flow direction is from left to right. The platelet color in silico is rendered to match the in vitro counterparts. The in vitro images for panels B1 and B2 were adopted from Ruggeri et al.¹³  under elevated shear rates (10 000∼20 000 s⁻¹) with human normal plasma VWF (whole blood). The in vitro counterpart of panel B3 was adopted from Chauhan et al³⁹  with endothelial VWF (ultra-long) under venous shear rates. Both results were obtained without platelet activation.