Simulation of red blood cell deformation and radial migration in microvessels

Abstract

The width of the cell-free layer near walls of microvessels strongly influences the resistance to blood flow in microvessels. However, the radial migration of red blood cells in flowing blood is not well understood from a mechanical viewpoint. Here, a theoretical method is used to simulate the motion and deformation of mammalian red blood cells in microvessels. Each red blood cell is represented as a set of interconnected viscoelastic elements in two dimensions. The motion and deformation of the cell in a microvessel and the motion of the surrounding plasma is computed using a finite-element numerical method. In simulations of red blood cell motion in capillary-sized channels, initially circular cell shapes rapidly approach shapes typical of those seen experimentally in capillaries, convex in front and convex at the rear. An isolated red blood cell entering an 8-μm capillary close to the wall is predicted to migrate in the radial direction as it traverses the capillary, achieving a position near the center-line after traveling a distance of about 60 μm. Cell trajectories agree closely with those observed in microvessels of the rat mesentery. Supported by NIH grant HL34555.