Simulation of steatosis zonation in liver lobule—a continuummechanical bi-scale, tri-phasic, multi-component approach

Abstract

The human liver is an important metabolic organ which regulates metabolism of the body in a complex time depending and non-linear coupled functionperfusion-mechanism. Harmful microstructure failure strongly affects the viability of the organ. The excessive accumulation of fat in the liver tissue, known as a fatty liver, is one of the most common liver micro structure failures, especially in western countries. The growing fat has a high impact on the blood perfusion and thus on the functionality of the organ. This interaction between perfusion, growth of fat and functionality on the hepatic microcirculation is poorly understood and many biological aspects of the liver are still subject of discussion. The presented computational model consists of a bi-scale, tri-phasic, multi-component approach based on the theory of porous media. The model includes the stress and strain state of the liver tissue, the transverse isotropic blood perfusion in the sinusoidal micro perfusion system. Furthermore, we describe the glucose metabolism in a two-scale PDE-ODE approach whereas the fat metabolism is included via phenomenological functions. Different inflow boundary conditions are tested against the influence on fat deposition and zonation in the liver lobules. With this example we can discuss biological assumptions and get a better understanding of the coupled function-perfusion ability of the liver.