Platelet Retraction Forces Induced Under High Shear Gradient Activation

Hemodynamics play an important role in the activity of platelets. High shear rate gradients can occur at locations where blood vessels bend, branch, or narrow and can arise at a vascular stent or artificial valve. These shear gradients have been observed to cause platelets to adhere to the vessel wall, leading to their activation and aggregation [1, 2]. High shear gradients can cause a self-sustaining process where platelet aggregation increases the local shear gradient, further causing platelets to adhere and aggregate. This process can become dangerous if the aggregate grows large enough to obstruct the vessel or if it detaches and clogs a vessel downstream.