Graduate Studies


First Advisor

Linxia Gu

Date of this Version

Summer 5-2018


Sedaghati, F. (2018). Bifurcation Stenting For Malignant Hilar Biliary Obstruction: A Comparison Between Dedicated And Separate Y-Shape Stents. Retrieved from Digital Commons, University of Nebraska-Lincoln


Thesis Presented to Faculty of The Graduate College at University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Mechanical Engineering & Applied Mechanics, Under the Supervision of Professor Linxia Gu, Lincoln, Nebraska: May 2018

Copyright © 2018 Farbod Sedaghati


Hilar cholangiocarcinoma is one of the most common disorders of biliary obstruction. Various stent configurations have been used for the palliative treatments of the biliary bile duct, including dedicated Y-shaped (DYS) stent and two-piece stent forming a Y-shape, also referred to as a separate Y-shape (SYS) stent. The mechanical characterizations of the bifurcating stents are scare. The aim of this study is to characterize the mechanical performance of both DYS and SYS self-expanding Nitinol stents using finite element method for better understanding of the biomechanical environment changes on the bile duct and its clinical implications. The crimping and expansion of both stents in the bile duct was simulated. The hyperelastic constitutive model of porcine bile ducts was constructed from tensile tests. The acute performance of both stents was quantified and compared in terms of the lumen gain, wall deformation and stress. Results showed the SYS stent provided better lumen gain, but larger stress and strain on the bile duct wall, compared to the DYS. A larger wall stress is generally associated with tissue remodeling and thus chronic complications. Also, the efficacy of the two Y-stenting methods was compared with respect to plastic strain distribution, stent migration, and delivery challenges. This work might facilitate the pre-surgery planning and new stent design.

Advisor: Linxia Gu