Hemodynamic simulation of two-way artery bypass graft model with the interaction of blood-arterial wall-microcirculation

Background: There are problems such as intimal hyperplasia leading to restenosis after artery bypass graft surgery. A detailed understanding of hemodynamics is very important for the treatment of arterial stenosis. Objective: The novel model of two-way artery bypass graft considering microcirculation function is proposed to investigate hemodynamic characteristics. Methods: The two-way artery bypass graft model with the interaction of blood-arterial wall-microcirculation is constructed. Different suture angles (20°, 30°, 45°) in the model are considered to compare the differences of hemodynamics. The fluid-structure interaction and a seepage condition are adopted. Results: The results show that almost all blood flows into the graft tubes when it comes to the bifurcation between the graft tubes and the host artery. The blood flow is symmetrically distributed in the upper and lower graft tubes. The peak pressures in the 20°, 30° and 45° models are about 370, 750 and 500 Pa respectively. Sequentially, the wall shear stresses of approximately 3, 0.4 and 2 Pa in the three models are generated in the post-stenotic region. The more suitable distributions and levels of pressure and wall shear stress are generated in the 45° model in contrast to the 20° and 30° models. Conclusion: It indicates that the addition of microcirculation could better simulate the physiological flow characteristics. Compared with the 20° and 30° models, the 45° model produces better hemodynamic effects. 45° may be the optimal bypass graft angle.