Hemodynamic studies of platelet thrombosis using microfluidics

Platelets contribute to thrombus formation in a variety of ways. Platelet adhesion, activation, and thrombus growth depend greatly on the type of hemodynamic environment surrounding an inciting event. Microfluidic systems may be used to explore these relationships. In this review, we describe some important considerations required in the design of a microfluidic system and identify some limitations that may require use of a macroscale system.

Choice of a hemodynamic model for occlusive thrombosis in arteries

Intravascular thrombosis can lead to heart attacks and strokes that together are the leading causes of death in the US (Kochanek, K.D., Murphy, S.L., Xu, J.Q., 2014). The ability to identify the offending biofluid mechanical conditions and predict the timescale of thrombotic occlusion in vessels and devices may improve patient outcomes. A computational model was developed to describe the growth of thrombus based on the local hemodynamic shear rate. The model predicts thrombus deposition based on initial geometric and fluid mechanical conditions, which are updated throughout the simulation to reflect the changing lumen dimensions. Thrombus growth and occlusion from whole blood was measured in in vitro experiments using stenotic glass capillary tubes, a PDMS microfluidic channel, and a PTFE stenotic aorto-iliac graft. Comparison of the predicted occlusion times to experimental results shows excellent agreement. The results indicate that local shear rate plays a critical role in acute thrombosis, and that hemodynamic characterization may have clinical utility.