title: On Studying the Interaction Between Different Stent Models and Rabbit Tracheal Tissue: Numerical, Endoscopic and Histological Comparison.
abstract: Stenting technique is employed worldwide for treating atherosclerotic vessel and tracheal stenosis. Both diseases can be treated by means of metallic stents which present advantages but are affected by the main problem of restenosis of the stented area. In this study we have built a rabbit trachea numerical model and we have analyzed it before and after insertion and opening of two types of commercial stent: a Zilver(®) Flex™ Stent and a WallStent™. In experimental parallel work, two types of stent were implanted in 30 New Zealand rabbits divided in two groups of 10 animals corresponding to each stent type and a third group made up of 10 animals without stent. The tracheal wall response was assessed by means of computerized tomography by endoscopy, macroscopic findings and histopathological study 90 days after stent deployment. Three idealized trachea models, one model for each group, were created in order to perform the computational study. The animal model was used to validate the numerical findings and to attempt to find qualitative correlations between numerical and experimental results. Experimental findings such as inflammation, granuloma and abnormal tissue growth, assessed from histomorphometric analyses were compared with derived numerical parameters such as wall shear stress (WSS) and maximum principal stress. The direct comparison of these parameters and the biological response supports the hypothesis that WSS and tensile stresses may lead to a greater tracheal epithelium response within the stented region, with the latter seeming to have the dominant role. This study may be helpful for improving stent design and demonstrates the feasibility offered by in-silico investigated tracheal structural and fluid dynamics.
authors.affiliation: Aragón Institute of Engineering Research, University of Zaragoza, C/María de Luna s/n, 50018, Zaragoza, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Chaure
authors.affiliation: Grupo de Investigación Técnicas de Mínima Invasión (GITMI), Faculty of Veterinary, Universidad de Zaragoza, C/Miguel Servet 177, 50013, Zaragoza, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Serrano
authors.affiliation: Grupo de Investigación Técnicas de Mínima Invasión (GITMI), Faculty of Veterinary, Universidad de Zaragoza, C/Miguel Servet 177, 50013, Zaragoza, Spain.|École Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704, Maisons-Alfort, France.
authors.forename: R
authors.initials: R
authors.lastname: Fernández-Parra
authors.affiliation: Aragón Institute of Engineering Research, University of Zaragoza, C/María de Luna s/n, 50018, Zaragoza, Spain. fany@unizar.es.|Centro de Investigación en Red en Bioingeniería, CIBER-BBN, Biomateriales y Nanomedicina, C/Poeta Mariano Esquillor s/n, 50018, Zaragoza, Spain. fany@unizar.es.
authors.forename: E
authors.initials: E
authors.lastname: Peña
authors.affiliation: Grupo de Investigación Técnicas de Mínima Invasión (GITMI), Faculty of Veterinary, Universidad de Zaragoza, C/Miguel Servet 177, 50013, Zaragoza, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Lostalé
authors.affiliation: Centro de Investigación en Red en Bioingeniería, CIBER-BBN, Biomateriales y Nanomedicina, C/Poeta Mariano Esquillor s/n, 50018, Zaragoza, Spain.|Grupo de Investigación Técnicas de Mínima Invasión (GITMI), Faculty of Veterinary, Universidad de Zaragoza, C/Miguel Servet 177, 50013, Zaragoza, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: De Gregorio
authors.affiliation: Aragón Institute of Engineering Research, University of Zaragoza, C/María de Luna s/n, 50018, Zaragoza, Spain.|Centro de Investigación en Red en Bioingeniería, CIBER-BBN, Biomateriales y Nanomedicina, C/Poeta Mariano Esquillor s/n, 50018, Zaragoza, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Martínez
authors.affiliation: Aragón Institute of Engineering Research, University of Zaragoza, C/María de Luna s/n, 50018, Zaragoza, Spain.|Centro de Investigación en Red en Bioingeniería, CIBER-BBN, Biomateriales y Nanomedicina, C/Poeta Mariano Esquillor s/n, 50018, Zaragoza, Spain.|Departamento de Ingeniería Mecánica, Energética y de Materiales, Universidad Pública de Navarra, Campus Arrosadía, 31006, Pamplona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Malvè
mesh_terms: D000818:Animals; D003198:Computer Simulation; D004195:Disease Models, Animal; D004724:Endoscopy; D011474:Prosthesis Design; D011817:Rabbits; D015607:Stents; D014057:Tomography, X-Ray Computed; D014132:Trachea / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D014135:Tracheal Stenosis / Q000473:pathology / Q000503:physiopathology / Q000601:surgery
keywords: Finite element method; Fluid–structure interaction; Nitinol; Trachea; WallstentTM; ZilverFlexTM stent