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Author
Perales de Rocafiguera, Bruno
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An aortic aneurysm is a permanent dilatation of the largest blood vessel in the body, the aorta. The presence of this phenomenon can eventually lead to a tear in the inner vascular tissue of the artery, known as aortic dissection. This disease has an estimated incidence of 6 per 100,000 people per year, with a mortality of up to 50%. Current treatments range from pharmacology and drugs to open surgery and intravascular synthetic stenting. The limitation of these techniques is that they are merely a containment of the disease, they have high mortality, morbidity, and reintervention rates. Tissue regeneration and patient recovery are not promoted. Aortyx has developed a bioresorbable adhesive patch that promotes tissue regeneration and mimics the mechanical properties of the aortic wall. The patch can be implanted in the diseased vessel where the dissection is located by means of a minimally invasive delivery device consisting of an endovascular catheter and a flower-shaped nitinol deployer.
The main objective of this project is to apply the finite element analysis method to analyze, iterate and optimize the device through which the corresponding endovascular treatment is performed. Firstly, the process of implantation of the patch to the aortic wall is studied; this process determines the capacity of the system to fix the patch in the affected region of the aorta. Parallelly, the folding and unfolding process of the endovascular device is studied; this process determines the capability of the system to correctly introduce the patch in the catheter and release it in the corresponding region of the aorta.
In this project, the parameters that allow the definition of the simulation models used to study the behavior of the endovascular device have been determined. It has been demonstrated that the simulation models faithfully reflect the real behavior of the system. Finite Element Analysis has made it possible to define a geometry of the deployer that improves the behavior of the system in the process of folding inside the catheter and unfolding out of it in a straight and deflected fashion. In addition, it has also improved the behavior in the process of implantation of the patch to the aortic wall. This new deployer design has been used to determine the parameters that define the folding and unfolding process of the endovascular device. The use of the simulation models has allowed to determine the optimal combination between the spoke concavity of the deployer’s petals and the wire diameter of its filaments. Finally, the geometry of the deployer’s stem has been modified to improve the performance of the system in the unfolding process through the deflected path of the catheter’s end tip.
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