title: A methodology for the customized design of colonic stents based on a parametric model.
abstract: The choice of necessary stent properties depends mainly on the length of the stenosis and degree of occlusion. So a stent design with variable radial stiffness along its longitudinal axis would be a good option. The design proposed corresponds to a tube-based stent with closed diamond-shaped cells made from a NiTi alloy. By acting independently on different geometric factors, variable geometries can be obtained with different radial force reactions. A design adjustment according to specific requirements, in order to get a better fit to ill-duct and reduces complications, is possible. A parametric analysis using finite element has been conducted to determine the influence of slot length, number of circumferential slots, tube thickness and shape-factor on stent mechanical behavior, which allow eliminating the need for extensive experimental work and knowing and quantifying the influence of those factors. The results of finite element simulations have been used, by means of least-squares fit techniques, to obtain analytical expressions for the main mechanical characteristics of the stent (Chronic Expansive Radial Force and Radial Compression Resistance) in terms of the different geometrical factors. This allows the stent geometry to be customized without launching an iterative and costly process of modeling and simulation for each case.
authors.affiliation: Department of Mechanical Engineering, University of Zaragoza, María de Luna 3, 50018 Zaragoza, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Puértolas
authors.affiliation: Department of Mechanical Engineering, University of Zaragoza, María de Luna 3, 50018 Zaragoza, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Navallas
authors.affiliation: Department of Surgery, University of Zaragoza, Domingo Miral s/n, 50009 Zaragoza, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Herrera
authors.affiliation: Department of Manufacturing Engineering, University of Zaragoza, María de Luna 3, 50018 Zaragoza, Spain.
authors.forename: E
authors.initials: E
authors.lastname: López
authors.affiliation: Department of Gastroenterology, Lozano Blesa University Hospital, Zaragoza, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Millastre
authors.affiliation: Department of Mechanical Engineering, University of Zaragoza, María de Luna 3, 50018 Zaragoza, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Ibarz
authors.affiliation: Department of Mechanical Engineering, University of Zaragoza, María de Luna 3, 50018 Zaragoza, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Gabarre
authors.affiliation: Department of Material Science, Univ. of Zaragoza, María de Luna 3, 50018 Zaragoza, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Puértolas
authors.affiliation: Department of Mechanical Engineering, University of Zaragoza, María de Luna 3, 50018 Zaragoza, Spain. Electronic address: lugravi@unizar.es.
authors.forename: L
authors.initials: L
authors.lastname: Gracia
mesh_terms: D003251:Constriction, Pathologic; D020342:Finite Element Analysis; D055595:Mechanical Phenomena; D011474:Prosthesis Design; D015607:Stents
keywords: Customized parametric design; Mechanical properties; Non-linear finite element analysis; Radial force calibration; Self-expanding Colonic stent; Stent design parameters