5,945 research outputs found
Vascular remodeling after endovascular treatment: quantitative analysis of medical images with a focus on aorta
No full textIn the last years, the convergence of advanced imaging techniques and endovascular procedures
has revolutionized the practice of vascular surgery. However, regardless the anatomical
district, several complications still occur after endovascular treatment and the impact of endovascular
repair on vessel morphology remains unclear. Starting from this background, the
aim of this thesis is to ll the gaps in the eld of vessel remodeling after endovascular procedure.
Main focus of the work will be the repair of the aorta and, in particular thoracic and
thoracoabdominal treatments. Furthermore an investigation of the impact of endovascular
repair on femoro-popliteal arterial segment will be reported in the present work. Analyses of
medical images will been conducted to extract anatomical geometric features and to compare
the changes in morphology before treatment and during follow-up.
After illustrating in detail the aims and the outline of the dissertation in Chapter 1, Chapter
2 will concern the anatomy and the physiology of the aorta along with the main aortic
pathologies and the related surgical treatments. Subsequently, an overview of the medical
image techniques for segmentation and vessel geometric quantication will be provided.
Chapter 3 will introduce the concept of remodeling of the aorta after endovascular procedure.
In particular, two types of aortic remodeling will be considered. On one side remodeling can
be seen as the shrinkage of the aneurysmal sac or false lumen thrombosis. On the other side,
aortic remodeling could be seen as the changes in the aortic morphology following endograft
placement which could lead to complications.
Chapter 4 will illustrate a study regarding the analysis of medical images to measure the geometrical
changes in the pathological aorta during follow-up in patients with thoracoabdominal
aortic aneurysms treated with endovascular procedure using a novel uncovered device, the Cardiatis
Multilayer Flow Modulator.
Chapter 5 will focus on the geometrical remodeling of the aortic arch and descending aorta in
patients who underwent hybrid arch treatment to treat thoracic aneurysms. The goal of the
work is to develop a pipeline for the processing of pre-operative and post-operative Computed
Tomography images in order to detect the changes in the aortic arch physiological curvature
due to endograft insertion.
Chapter 6 will focuse on the use of 3D printing technology as valuable tool to support patient's
follow-up. In particular, we report a case of a patient originally treated with endovascular
procedure for type B aortic dissection and which experimented several complications during
follow-up. 3D printing technology is used to show the remodeling of the aortic vasculature
during time.
Chapter 7 will concern patient-specic nite element simulations of aortic endovascular procedure.
In particular, starting from a clinical case where complication developed during followup,
the predictive value of computational simulations will be shown.
Chapter 8 will illustrate a study concerning the evaluation of morphological changes of the
femoro-popliteal arterial segment due to limb exion in patients undergoing endovascular
treatment of popliteal artery aneurysms
Finite element analysis of TAVI: Impact of native aortic root computational modeling strategies on simulation outcomes
No full textIn the last few years, several studies, each with different aim and modeling detail, have been proposed to investigate transcatheter aortic valve implantation (TAVI) with finite elements. The present work focuses on the patient-specific finite element modeling of the aortic valve complex. In particular, we aim at investigating how different modeling strategies in terms of material models/properties and discretization procedures can impact analysis results. Four different choices both for the mesh size (from 20k elements to 200k elements) and for the material model (from rigid to hyperelastic anisotropic) are considered. Different approaches for modeling calcifications are also taken into account. Post-operative CT data of the real implant are used as reference solution with the aim of outlining a trade-off between computational model complexity and reliability of the results
Alice and Cliff Donahue
No full textPhotograph - Friends of Alice B. and William Clifford Donahue, Athabasca, Alberta. Seated, left to right: Cliff Donahue, Joe Mikkelsen, Beryl Mikkelsen, and Marge Logan. Standing, left to right: Don Logan, Alice B. Donahue, Aaron Jones, Lorene Jones, and Beatrice Par
Alice B. Donahue - 09
No full textPhotograph - Alice B. Donahue at flooded campsite on the Athabasca River, Athabasca, Albert
- …
