Amount of platelets adhering to a collagen-coated surface in BSS, GTA, and type 3 vWD at various shear rates. Data represent the amount of adherent platelets on the surface, expressed as an arbitrary units, at 7 minutes of perfusion of blood from each patient (numbered as “−1”; see Table 1) with BSS (○), type 3 vWD (▿), and GTA (▵) at the indicated shear rates. In BSS and type 3 vWD, the maxmal value at 340 s⁻¹ decreased as a function of shear rate, with no detectable platelet adhesion at shear rates greater than 1,210 s⁻¹, whereas adhesion in control blood (•) increased as a function of shear rate. Thrombus growth in GTA blood was absent at all shear rates.