Wyniki wyszukiwania - BazTech

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Numerical and experimental analysis of balloon angioplasty impact on flow hemodynamics improvement

Tomaszewski Michał, Sybilski Kamil, Małachowski Jerzy, Wolański Wojciech, Buszman Piotr P.

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 3

169--183

EN

Purpose: The paper focuses on the numerical and experimental evaluation of the fluid flow inside chosen fragments of blood vessels. In the first stage of the study, the experimental tests were conducted using a research test stand, designed to be used in this evaluation. The study evaluated the blood flow through a silicone vessel with an implanted coronary stent. Methods: The PIV method was used in order to visualize the flow vectors inside a silicone vessel. Deformed vessel geometry implemented for computational fluid dynamics purposes was obtained owing to a non-linear simulation of the stent expansion (angioplasty process) in a silicone vessel. Additionally, a vessel model with a statistical 55% area stenosis and an irregular real vessel with an atherosclerotic plaque were also subjected to analysis from the hemodynamic flow point of view. A vessel with a statistical stenosis was also used to simulate the angioplasty process, which resulted in obtaining a flow domain for the vessel with an atherosclerotic plaque after the stent implantation. Results: For each case, distributions of parameters such as OSI or TAWSS were also analyzed and discussed. The areas of low TAWSS values appear close to the stent struts. Conclusions: Stents with increased diameters, compared to the normal vessel diameter, create a higher risk of occurrence of the areas with low WSS values. Excessive stent deformation can cause inflammation by injuring the vessel and can initiate the restenosis and thrombotic phenomena through the increased vessel diameter.

2

Numerical analysis of stent expansion process in coronary artery stenosis with the use of non-compliant balloon

Bukala J., Kwiatkowski P., Malachowski J.

Biocybernetics and Biomedical Engineering

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2016

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Vol. 36, no. 1

145--156

EN

In the paper the authors present an applied methodology, data and numerical results for numerical analysis of the stent crimping process and stent implantation in the coronary artery stenosis with the use of a non-compliant angioplasty balloon. The authors focused on the modeling methodology of balloon angioplasty with minimum possible simplification, i.e.: a full load path (compression and inflation in single analysis), 3D unsymmetrical geometry and discretization, highly nonlinear material models (hyperelasticity, plastic kinematic formulation, crushable foam) and sophisticated contact models (bodies with highly different stiffness). The use of a highly compressible crushable foam material model for an arterial plaque is considered as the most original part of the work. The presented results allow for better understanding of the mechanisms governing stent crimping and implementation.

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Finite element analysis of the percutaneous coronary intervention in a coronary bifurcation

Bukała J. K., Małachowski J., Kwiatkowski P.

Acta of Bioengineering and Biomechanics

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2014

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Vol. 16, no. 4

23--31

EN

Purpose: The paper presents the process of numerical modeling and simulation of balloon angioplasty of the coronary artery using Finite Element Method. Methods: The authors focused on the issue of adequate pressure applying in an arterial tissue during the post-dilatation process in the 'kissing balloon' stenting technique applied to patients with bifurcation stenosis. Despite great progress in the field of interventional cardiology, angioplasty in bifurcations still belongs to the most difficult interventions, generally being less effective and more risky than in the cases of straight stenosis.Results: During the modeling procedures and further simulations, the authors focused on mutual cooperation of non - compliant angioplasty balloons and the coronary artery. The other goal was to develop a sufficiently accurate model of the coronary artery fragment, including its bifurcation and angioplasty balloons, however it was decided to ignore the modeling of coronary stents.Conclusions: The undertaken issue is considered as relatively complicated and complex but, in the authors opinion, the implementation of advanced computer aided engineering techniques may, in this case, answer several important questions without the need of performing costly and aggravating in vivo tests.

4

Modelowanie przepływu krwi przez naczynie wieńcowe ze stentem

Kurowska-Nouyrigat W., Szumbarski J.

Aktualne Problemy Biomechaniki

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2009

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z. 3

115--120

PL

Jedną z popularniejszych nieinwazyjnych metod leczenia arteriosklerozy jest angioplastyka i implantacja stentów (na świecie około 1 min interwencji rocznie, z czego 60-80% ze stentem). Niestety, w 20-30% przypadków wprowadzeniu stentu towarzyszy powikłanie polegające na przeroście śródbłonka powodującym restenozę w przeciągu 3-6 miesięcy po implantacji. Stosując realistyczny, trójwymiarowej model geometryczny naczynia z implantowanym stentem, przeprowadzono analizę czynników geometrycznych i przepływowych ukazujące ich związek z rozwojem restenozy.

EN

Nowadays, cardiac disease are one of the most common cause of death. Each year almost one million of angioplasty interventions and stents implantations are made all over the world. Unfortunately, in 20-30% of cases neointimal proliferations leads to restenosis occurring within the following period of 3-6 months. The aim of the current research is to analyse how geometrical changes inflicted by the stent implantation affect the WSS distribution.

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Microscopic and histological analysis of the processes occurring in the aperture and wall of a coronary vessel after stent implantation

Grygier D., Kuropka P., Dudziński W.

Acta of Bioengineering and Biomechanics

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2008

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Vol. 10, nr 3

55-60

EN

The serious problem of angioplasty is restenosis, which relates to approx. 15–30% of all the patients subjected to the procedure. The present research was inspired by an attempt to explain this phenomenon and to analyse its causes. Two coronary arteries coming from the patients after stent implantation were subjected to analysis using light and electron microscopy. As a result of expansion of the stent and pressing the implant metallic structure into the artery wall, it comes to breaking the endothelium continuity, uncovering the structures of the intercellular matrix and the internal membrane and, consequently, to creation of a thrombus in the damaged area. As a result of the tissue response, the extracellular matrix is created and neointime formed.