COMPUTER AIDED SURGERY: APPLICATION TO AORTIC DISSECTION

Le résumé fourni par la source

Cardiovascular diseases (CVDs) are the leading cause of mortality in the European Union and accounted for about 36% of all deaths in 2019. Among these diseases, aortic dissection is relatively unknown and difficult to treat, with a survival rate for most severe cases not exceeding 10%. This pathology occurs when an injury leads to a localized tear of the innermost layer of the aorta, called the entry port. It allows blood to flow between the layers of the aortic wall, forcing the layers apart and creating a false lumen. The dissection of these layers may extend over a long portion of the thoracic and abdominal aorta. Endovascular treatment seeks to obliterate the entrances to the false lumen with a stent. The currently available surgical tools for endovascular procedures are selected only from information based on medical imaging techniques. The images are carried out before the intervention and therefore do not consider the deformation of the vascular structure by the implementation of the prosthesis. While many biomechanical studies have been done on the endovascular treatment of aneurysms of the abdominal aorta, there are, however, very few studies on aortic dissections. However,there are few studies as well on the postoperative demonstration of blood flow phenomena in the aortic dissection endovascular treatment. It is crucial to study the hemodynamic of blood in the aorta after an intervention, because the deployment of a stent leads to modifications in the blood flow. For the surgeons, the procedure can only be performed empirically, using MRI-4D images to view the post-operative flow of the patient's blood in the aorta with the stent. The numerical simulation method, instead allows us to simulate the complete endovascular procedure for an adapted recommendation during surgical planning. This thesis aims to present a numerical tool, from the open-source software FOAM-Extend, allowing for Multiphysics numerical simulations, performing the fluid-structure coupling between the hemodynamics and the arterial deformation to assist in the planning process. In addition, using Abaqus software, we realized the placement of the surgical tools in a “biomechano-faithful” aortic dissection model. This model will be able to predict the deformation of the flap and the artery wall during the implementation of the tools. Also, with the numerical simulation, we could obtain the postoperative hemodynamic in the aorta, to predict the modification of flow. Finally, the numerical simulation results are compared with the MRI data to have a validation of the numerical models. There is a parallel thesis that focuses on flows in aorta phantoms PIV applied in AD (same geometry) and enables the confrontation and inter-validation of both model methods at the time of the study.

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