title: Simulation of longitudinal stent deformation in a patient-specific coronary artery.
abstract: In percutaneous coronary intervention (PCI), stent malapposition is a common complication often leading to stent thrombosis (ST). More recently, it has also been associated with longitudinal stent deformation (LSD) normally occurring through contact of a post balloon catheter tip and the protruding malapposed stent struts. The aim of this study was to assess the longitudinal integrity of first and second generation drug eluting stents in a patient specific coronary artery segment and to compare the range of variation of applied loads with those reported elsewhere. We successfully validated computational models of three drug-eluting stent designs when assessed for longitudinal deformation. We then reconstructed a patient specific stenosed right coronary artery segment by fusing angiographic and intravascular ultrasound (IVUS) images from a real case. Within this model the mechanical behaviour of the same stents along with a modified device was compared. Specifically, after the deployment of each device, a compressive point load of 0.3N was applied on the most malapposed strut proximally to the models. Results indicate that predicted stent longitudinal strength (i) is significantly different between the stent platforms in a manner consistent with physical testing in a laboratory environment, (ii) shows a smaller range of variation for simulations of in vivo performance relative to models of in vitro experiments, and (iii) the modified stent design demonstrated considerably higher longitudinal integrity. Interestingly, stent longitudinal stability may differ drastically after a localised in vivo force compared to a distributed in vitro force.
authors.affiliation: Computational Engineering and Design Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK.
authors.forename: Georgios E
authors.initials: GE
authors.lastname: Ragkousis
authors.affiliation: Southampton University Hospitals NHS Trust, Southampton, UK; Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Curzen
authors.affiliation: Computational Engineering and Design Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK. Electronic address: N.W.Bressloff@soton.ac.uk.
authors.forename: Neil W
authors.initials: NW
authors.lastname: Bressloff
mesh_terms: D003198:Computer Simulation; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D054855:Drug-Eluting Stents; D004867:Equipment Design; D004868:Equipment Failure; D006801:Humans; D055595:Mechanical Phenomena; D008955:Models, Cardiovascular; D013997:Time Factors; D018084:Ultrasonography, Interventional
keywords: Finite element analysis; Longitudinal stent deformation; Patient specific model; Stent malapposition; Stents