An ovine in vivo framework for tracheobronchial stent analysis

• Published in: Biomechanics and modeling in mechanobiology Vol. 16; no. 5; pp. 1535 - 1553
• Main Authors: McGrath, Donnacha J., Thiebes, Anja Lena, Cornelissen, Christian G., O’Shea, Mary B., O’Brien, Barry, Jockenhoevel, Stefan, Bruzzi, Mark, McHugh, Peter E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2017; Springer Nature B.V
• Subjects: Airway management; Alloys - pharmacology; Animals; Biological and Medical Physics; Biomechanics; Biomedical Engineering and Bioengineering; Biophysics; Breathing; Bronchi - diagnostic imaging; Bronchi - physiology; Computed tomography; Computer applications; Computer Simulation; Deformation mechanisms; Engineering; Functional Residual Capacity; Granulation; Human motion; Imaging, Three-Dimensional; Implants; Lungs; Mechanical properties; Migration; Original Paper; Pressure; Respiratory tract; Sheep; Space life sciences; Stents; Stress, Mechanical; Surgical implants; Theoretical and Applied Mechanics; Tomography, X-Ray Computed; Total Lung Capacity; Trachea - diagnostic imaging; Trachea - physiology; Tumors; Ventilation; Finite element method; Stenting; Biomechanical; Nitinol; Lung; Tracheobronchial
• ISSN: 1617-7959; 1617-7940
• DOI: 10.1007/s10237-017-0904-8

Tracheobronchial stents are most commonly used to restore patency to airways stenosed by tumour growth. Currently all tracheobronchial stents are associated with complications such as stent migration, granulation tissue formation, mucous plugging and stent strut fracture. The present work develops a computational framework to evaluate tracheobronchial stent designs in vivo. Pressurised computed tomography is used to create a biomechanical lung model which takes into account the in vivo stress state, global lung deformation and local loading from pressure variation. Stent interaction with the airway is then evaluated for a number of loading conditions including normal breathing, coughing and ventilation. Results of the analysis indicate that three of the major complications associated with tracheobronchial stents can potentially be analysed with this framework, which can be readily applied to the human case. Airway deformation caused by lung motion is shown to have a significant effect on stent mechanical performance, including implications for stent migration, granulation formation and stent fracture.