Numerical investigation of venous valve flow conditions in relation to development of disease

Venous valves are vital to the proper function of the circulatory system. These valves open and close with pressure oscillations due to contraction and relaxation of the surrounding skeletal muscle, enabling return of blood from the lower extremities against gravity back to the heart. However, major diseases such as deep vein thrombosis (DVT) are known to originate in the vicinity of venous valves. DVT can further progress into pulmonary embolism (PE), a leading cause of death in the United States, and an especially serious concern for those who experience extended periods of physical inactivity (such as hospitalization or long plane rides). Here, we use a three-dimensional (3-D) fully-coupled fluid-solid interaction model based on the lattice-Boltzmann model and the lattice spring model to study the effect of valve morphology on disease-conducive flow conditions. Specifically, we investigate the effect of valve mechanical properties and 3-D shape on shear stress, fluid stasis and residence time, which are generally linked to thrombus formation in a variety of physiological locations. Our findings will help to enable better identification of at-risk patients to take measures to prevent DVT and PE.