Ureteral stents are a measure used for many medical issues involving urology, such as kidney stones or kidney transplants. The purpose of applying stents is to help relieve the urine flow while the ureter is either blocked or trying to close itself, which creates blockages. These ureteral stents, while necessary, cause pain and discomfort to patients due to them being a solid that moves around inside the patients’ body. The ureter normally moves urine to the bladder through peristaltic forces. Due to the ureter being a hyperelastic material, these peristaltic forces cause the ureter to deform easily, making it necessary for the stent to properly move the urine that flows through it for the patient not to face further medical complications. In this study, we seek to find a relation between the amount of stent side holes and the overall flow rate inside the stent with the ureter contracting due to peristalsis. A fully coupled fluid-structure interaction (FSI) model is developed to visualize how the ureter deforms due to peristalsis and the subsequent effect on the urine flow due to the ureter’s deformation. Numerical simulations using COMSOL Multiphysics, a commercial finite-element based solver, were used to study the fluid-structure interaction, and determine whether the stent performs more properly as the amount of stent side holes increases. The results showed that the stent model with a 10 mm distance between side hole pairs provided the highest outlet flow rate, which indicates a proper stent design that allows for maximized urine discharge. We hope this study can help improve the stent design in kidney transplant procedures to further ease the inconvenience on the patients.
Martinez, E, Xu, B, Li, J, & Yang, Y. "Numerical Study of Fully Coupled Fluid-Structure Interaction of Stented Ureter by Varying the Stent Side-Holes." Proceedings of the ASME 2021 Fluids Engineering Division Summer Meeting. Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics. Virtual, Online. August 10–12, 2021. V001T02A037. ASME. https://doi.org/10.1115/FEDSM2021-64044
Proceedings of the ASME 2021 Fluids Engineering Division Summer Meeting. Volume 1: Aerospace Engineering Division Joint Track; Computational Fluid Dynamics