A methodology for the customized design of colonic stents based on a parametric model. (July 2017)

• Record Type: Journal Article
• Authors: Puértolas, S.; Navallas, D.; Herrera, A.; López, E.; Millastre, J.; Ibarz, E.; Gabarre, S.; Puértolas, J.A.; Gracia, L.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 71(2017)
• Page Start: 250
• Page End: 261
• Publication Date: 2017-07
• Subjects: Self-expanding Colonic stent -- Customized parametric design -- Mechanical properties -- Non-linear finite element analysis -- Stent design parameters -- Radial force calibration; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2017.03.023
• Languages: English
• ISSNs: 1751-6161

Abstract

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. Graphical abstract: Highlights: Methodology for the design of customized self-expandable NiTi colonic stents. Study of the influence of geometric factors on the mechanical response of stents. Obtention of the surface stent behavior for different design parameters. Effective tool to adjust the stent design to needs without specific simulations. Bell-shaped colonic self-expandable stent design with variable radial stiffness.