Microconfined flow behavior of red blood cells in vitro

The high red blood cell (RBC) deformability is essential to optimal gas exchange between gas and tissues in microcirculation in vivo. This review is focused on the flow behavior of RBCs in microconfined geometries in vitro, such as circular section capillaries, rectangular channels and pores, where at least one transverse dimension is comparable to cell size. Experimental results on RBC velocity and shape are reviewed together with modeling predictions and numerical simulations. In spite of the progress made so far, the pathophysiological implications of altered RBC deformability are still to be fully elucidated, and more data from clinically-relevant experimental methods and modeling-based interpretation are needed. Future directions include the emerging application of microfluidics techniques to investigate RBC flow in complex geometries.