Publicação
Numerical simulation of the deployment process of an arterial stent: geometrical interactions and constitutive modelling
| Resumo: | The atherosclerosis is characterized by the accumulation of fatty deposits causing the progressive straitening of the vessels; this plaque build-up can obstruct the blood flow limiting other parts of the body from receiving blood rich in oxygen and nutrients. This condition affects several vessels in human body, mainly the coronary arteries and in case of complete obstruction it can result in myocardial infarction. Like in the coronary arteries the plaque build-up presents a high prevalence in the carotids and its obstruction can lead to a stroke. Currently, stenting is the most common procedure to treat atherosclerosis, and is preferable to angioplasty avoiding a new vessel straitening. The aim of this dissertation is to simulate the deployment of the stent within an atherosclerotic artery in order to understand the biomechanical behaviour of the device, as well as the stress fields induced to the artery. Stent deployment can cause severe injuries to the vessel such as tissue damage or even rupture and post-implantation problems like restenosis, re-narrowing of the blood vessel. A way to predict the stress fields is using computational methods; combining MRI with finite element analysis can significantly increase the understanding of stents deployment and its impact. Therefore, the use of computational methods on the study of stents’ deployment allowed the evaluation between different stents’ thicknesses and different expansion pressures as well as the prediction of the mechanical behaviour of the stent when it is implanted on an artery with cellular and calcified plaque. Analysing the obtained results in ANSYS simulation software is possible to conclude that during the inflation process the balloon has a very important role in stent deployment. When the expansion of the stent occurs by applying a direct pressure on its inner surface, the dogboning value has revealed to be higher than when the deployment of the stent is performed by inflating a balloon. Also, the deployment of both stents in calcified plaque revealed to reduce the expansion of the device, however the stress fields induced on the artery are lower for the simulation with calcified plaque than with the deployment in cellular plaque. Advanced techniques, new materials and geometries could help in the development of more and high-quality stent products; finite element analysis is a very resourceful tool, which can save time and speed-up the products research and their development. |
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| Autores principais: | Silva, Ana Teresa Pais Neto Moreira da |
| Assunto: | Atherosclerosis Stent Balloon Artery Finite element analysis Aterosclerose Balão Artéria Análise de elementos finitos |
| Ano: | 2018 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | The atherosclerosis is characterized by the accumulation of fatty deposits causing the progressive straitening of the vessels; this plaque build-up can obstruct the blood flow limiting other parts of the body from receiving blood rich in oxygen and nutrients. This condition affects several vessels in human body, mainly the coronary arteries and in case of complete obstruction it can result in myocardial infarction. Like in the coronary arteries the plaque build-up presents a high prevalence in the carotids and its obstruction can lead to a stroke. Currently, stenting is the most common procedure to treat atherosclerosis, and is preferable to angioplasty avoiding a new vessel straitening. The aim of this dissertation is to simulate the deployment of the stent within an atherosclerotic artery in order to understand the biomechanical behaviour of the device, as well as the stress fields induced to the artery. Stent deployment can cause severe injuries to the vessel such as tissue damage or even rupture and post-implantation problems like restenosis, re-narrowing of the blood vessel. A way to predict the stress fields is using computational methods; combining MRI with finite element analysis can significantly increase the understanding of stents deployment and its impact. Therefore, the use of computational methods on the study of stents’ deployment allowed the evaluation between different stents’ thicknesses and different expansion pressures as well as the prediction of the mechanical behaviour of the stent when it is implanted on an artery with cellular and calcified plaque. Analysing the obtained results in ANSYS simulation software is possible to conclude that during the inflation process the balloon has a very important role in stent deployment. When the expansion of the stent occurs by applying a direct pressure on its inner surface, the dogboning value has revealed to be higher than when the deployment of the stent is performed by inflating a balloon. Also, the deployment of both stents in calcified plaque revealed to reduce the expansion of the device, however the stress fields induced on the artery are lower for the simulation with calcified plaque than with the deployment in cellular plaque. Advanced techniques, new materials and geometries could help in the development of more and high-quality stent products; finite element analysis is a very resourceful tool, which can save time and speed-up the products research and their development. |
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