title: On the necessity of modelling fluid-structure interaction for stented coronary arteries.
abstract: Although stenting is the most commonly performed procedure for the treatment of coronary atherosclerotic lesions, in-stent restenosis (ISR) remains one of the most serious clinical complications. An important stimulus to ISR is the altered hemodynamics with abnormal shear stresses on endothelial cells generated by the stent presence. Computational fluid dynamics is a valid tool for studying the local hemodynamics of stented vessels, allowing the calculation of the wall shear stress (WSS), which is otherwise not directly possible to be measured in vivo. However, in these numerical simulations the arterial wall and the stent are considered rigid and fixed, an assumption that may influence the WSS and flow patterns. Therefore, the aim of this work is to perform fluid-structure interaction (FSI) analyses of a stented coronary artery in order to understand the effects of the wall compliance on the hemodynamic quantities. Two different materials are considered for the stent: cobalt-chromium (CoCr) and poly-l-lactide (PLLA). The results of the FSI and the corresponding rigid-wall models are compared, focusing in particular on the analysis of the WSS distribution. Results showed similar trends in terms of instantaneous and time-averaged WSS between compliant and rigid-wall cases. In particular, the difference of percentage area exposed to TAWSS lower than 0.4Pa between the CoCr FSI and the rigid-wall cases was about 1.5% while between the PLLA cases 1.0%. The results indicate that, for idealized models of a stented coronary artery, the rigid-wall assumption for fluid dynamic simulations appears adequate when the aim of the study is the analysis of near-wall quantities like WSS.
authors.affiliation: Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Chiastra
authors.affiliation: Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Migliavacca
authors.affiliation: Aragón Institute of Engineering Research (I3A), Universidad de Zaragoza, C/María de Luna s/n, E-50018 Zaragoza, Spain; Centro de Investigación Biomédica en Red-Bioingeniería Biomateriales y Nanomedicina (CIBER-BBN), C/Poeta Mariano Esquillor s/n, E-50018 Zaragoza, Spain.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Martínez
authors.affiliation: Aragón Institute of Engineering Research (I3A), Universidad de Zaragoza, C/María de Luna s/n, E-50018 Zaragoza, Spain; Centro de Investigación Biomédica en Red-Bioingeniería Biomateriales y Nanomedicina (CIBER-BBN), C/Poeta Mariano Esquillor s/n, E-50018 Zaragoza, Spain; Universidad Pública de Navarra, Departamento de Ingeniería Mecánica, Energética y de Materiales, Campus Arrosadía, E-31006 Pamplona, Spain. Electronic address: mauro.malve@unavarra.es.
authors.forename: Mauro
authors.initials: M
authors.lastname: Malvè
mesh_terms: D001696:Biomechanical Phenomena; D002857:Chromium; D003035:Cobalt; D003331:Coronary Vessels / Q000502:physiology; D006439:Hemodynamics; D057446:Hydrodynamics; D008954:Models, Biological; D011091:Polyesters; D015607:Stents; D013314:Stress, Mechanical
chemical_list: D011091:Polyesters; D002857:Chromium; D003035:Cobalt; C033616:poly(lactide)
keywords: Computational fluid dynamics; Coronary artery; Fluid–structure interaction; Stent; Wall shear stress