Patient-specific fluid–structure interaction model of bile flow: comparison between 1-way and 2-way algorithms

Abstract

Gallbladder disease is one of the most spread pathologies in the world. Despite the number of operations dealing with biliary surgery increases, the number of postoperative complications is also high. The aim of this study is to show the influence of the biliary system pathology on bile flow character and to numerically assess the effect of surgical operation (cholecystectomy) on the fluid dynamics in the extrahepatic biliary tree, and also to reveal the difference between 1-way and 2-way FSI algorithms on the results. Moreover, the bile viscosity and biliary tree geometry influence on the choledynamics were evaluated. Bile velocity, pressure, wall shear stress (WSS), displacements and von Mises stress distributions in the extrahepatic biliary tree are presented, and comparison is made between a healthy and a lithogenic bile. The patient-specific biliary tree model is created using magnetic resonance imaging (MRI) and imported in a commercial finite element analysis software. It is found that in the case of lithogenic bile, velocities have lower magnitude while pressures are higher. Furthermore, stress analysis of the bile ducts shows that the WSS distribution is found mostly prevailing in the common hepatic duct and common bile duct areas. It is shown that when it is necessary to evaluate the bile flow dynamics in urgent medical situations, 1-way analysis is acceptable. Nevertheless, 2-way FSI provides more accurate data, if necessary to evaluate the stress–strain state of bile ducts. The proposed model can be applied to medical practice to reduce the number of post-operative complications.

Keywords:

• Extrahepatic biliary tree
• choledynamics
• patient-specific modelling

Disclosure statement

No potential conflict of interest was reported by the author(s).

Acknowledgements

Alex G. Kuchumov acknowledges the Perm Region government grant for the development of the scientific school “Computer biomechanics and digital technologies in biomedicine”. The work is partly performed in the framework of the development program of the Scientific and Educational Mathematical Center of Privolzhskiy Federal District, project 075-02-2020-1478. The contribution of Vasily Vedeneev into the study of bile duct properties was supported by the Russian Science Foundation (grant No. 19-71-30012). Aleksandr Khairulin acknowledges the financial support of the Ministry of Science and Higher Education of the Russian Federation in the framework of the program of activities of the Perm Scientific and Educational Center “Rational Subsoil Use”.