The behavior between fluid and structure from coupling system of bile, bile duct, and polydioxanone biliary stent: A numerical method

The performance and effects of 12 different structures of stents in the bile duct were compared and used the finite element method. Numerical models of the 12 kinds of fluid-structure interaction(FSI) coupling systems were established to investigate the relationship between three aspects (velocity distribution of bile, wall shear stress (WSS) distribution of bile, and Von Mises Stress(VMS) distribution on the stent and bile duct) and the structural parameters of the stent (monofilament diameter and the number of braiding heads). After calculating and analyzing the simulation results yielding distributions of velocity, WWS, and VMS and regions of bile duct susceptibility to stenosis, they were consistent with previous findings on the locations of restenosis occurring after stent removal, indicating that the simulation results could provide a useful reference for studying biliary stents. The results of the simulations showed that (i) eddy currents were prone to occur at the stent ends regions; (ii) the WSS distribution of the bile fluid in contact with the stent and bile duct related to the stent structure; (iii) the high VMS on the stent and bile duct was prone to occur at the stent ends. The simulation results of 12 FSI coupling systems were studied and two superior stent model structures were obtained by comprehensive evaluation.