Simulation of a balloon expandable stent in a realistic coronary artery—Determination of the optimum modelling strategy

• Published in: Journal of biomechanics Vol. 43; no. 11; pp. 2126 - 2132
• Main Authors: Zahedmanesh, Houman, John Kelly, Daniel, Lally, Caitríona
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 10-08-2010; Elsevier; Elsevier Limited
• Subjects: Angioplasty, Balloon, Coronary - instrumentation; Arterial wall mechanics; Arteries; Atherosclerosis; Balloon expandable stent; Biological and medical sciences; Blood Vessel Prosthesis; Cardiovascular biomechanics; Computer Simulation; Computer-Aided Design; Computerized, statistical medical data processing and models in biomedicine; Coronary vessels; Coronary Vessels - physiopathology; Coronary Vessels - surgery; Diseases of the cardiovascular system; Equipment Failure Analysis; Finite element method; Geometry; Humans; Mathematical models; Medical equipment; Medical sciences; Modelling; Models and simulation; Models, Cardiovascular; Optimization; Physical Medicine and Rehabilitation; Prosthesis Design; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Stents; Surgical implants; Veins & arteries; Finite element method; Arterial wall mechanics; Balloon expandable stent; Cardiovascular biomechanics; Human; Computer simulation; Coronary artery; Instrumentation therapy; Modeling; Stent; Biomechanics; Blood vessel; Sounding balloon; Circulatory system; Vascular wall; Biomedical engineering
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/j.jbiomech.2010.03.050

Abstract Computational models of stent deployment in arteries have been widely used to shed light on various aspects of stent design and optimisation. In this context, modelling of balloon expandable stents has proved challenging due to the complex mechanics of balloon–stent interaction and the difficulties involved in creating folded balloon geometries. In this study, a method to create a folded balloon model is presented and utilised to numerically model the accurate deployment of a stent in a realistic geometry of an atherosclerotic human coronary artery. Stent deployment is, however, commonly modelled by applying an increasing pressure to the stent, thereby neglecting the balloon. This method is compared to the realistic balloon expansion simulation to fully elucidate the limitations of this procedure. The results illustrate that inclusion of a realistic balloon model is essential for accurate modelling of stent deformation and stent stresses. An alternative balloon simulation procedure is presented however, which overcomes many of the limitations of the applied pressure approach by using elements which restrain the stent as the desired diameter is achieved. This study shows that direct application of pressure to the stent inner surface may be used as an optimal modelling strategy to estimate the stresses in the vessel wall using these restraining elements and hence offer a very efficient alternative approach to numerically modelling stent deployment within complex arterial geometries. The method is limited however, in that it can only predict final stresses in the stented vessel and not those occurring during stent expansion, in which case the balloon expansion model is required.