The incompressible fluid flow around the geometries of cerebral artery aneurysms is studied in this thesis. The aneurysm is a local extension of a vessel. This disease is dangerous only in the case of rupture. Then the blood is released into the brain. The need of accurate computation of the velocity and pressure fields in this geometries is motivated exactly by the question which aneurysm has tendency to rupture. The finite element method (FEM) is used for the computation of the flow. A good domain discretization is one of the main step in FEM. Modern computed tomography is able to produce series of the two- dimensional images and it is necessary to create an appropriate three-dimensional model of the tissue. This thesis includes the description of the mesh generation and the ways to smooth and improve the meshes. In the theoretical part the equations of fluid flow are formulated. A suitability of a choice of boundary conditions is discussed. Weak formulation for the equations and its discretization are presented. In the practical part velocity and pressure fields are computed by the various finite elements. Wall shear stress which plays an important role in the evolution of an aneurysm is also computed on the introduced meshes. Comparison of mesh smoothing filters, used finite elements and used...

Bakgrund: Aortaaneurysm är en vidgning på stora kroppspulsådern, en asymtomatisk diagnos som kan blir livshotande om den brister. Aneurysm kan repareras med antingen öppen kirurgi eller endoskopiskt. Män är majoriteten av dessa patienter och rökning, hjärtkärlsjukdomar samt hög ålder utgör riskfaktorer. Syfte: Syftet med litteraturöversikten var att beskriva personers erfarenheter av att leva med ett aortaaneurysm. Metod: Designen är kvalitativ litteraturöversikt med induktiv ansats. Resultatartiklar söktes fram på databaserna CINAHL, PubMed och PsychInfo med hjälp av relevanta sökord för ämnet. Även manuella sökningar gjordes. De framtagna artiklarna lästes med hjälp Fribergs 5-stegsmodell och analyserades utifrån Graneheim och Lundmans kvalitativa innehållsanalys. Analysen resulterade i tre huvudkategorier och sju subkategorier. Resultat: Vägledning i att ha levt med aortaaneurysm, Emotionella aspekter av att ha levt med aortaaneurysm och Livet och vardagen med aortaaneurysm var de tre huvudkategorierna som framkom från analysen, och subkategorierna Information från vården, Kunskap kring diagnosen, Rädsla för diagnosen, Tankar kring döden, En framtid trots diagnos, Mötet med vården samt Begränsningar i vardagen. Information var det som var mest påtagligt och som under tidens gång visade sig kunna påverka övriga subkategorier både positivt och negativt beroende på mängd, leveranssätt och tidpunkt.  Slutsats: Genom denna litteraturöversikt visade sig erfarenheterna variera och dessa var individuella beroende på var i livet deltagaren befann sig och hur livet i övrigt var för deltagaren. Ytterligare studier behövs för att ta fram ett mer personcentrerat och individuellt tillmötesgående för personer med aortaaneurysm. / Background: Aortic aneurysm is a dilation of the aorta, an asymptomatic diagnosis that can become life-threatening if it burst. Aneurysms can be repaired with either open surgery or endoscopically. The majority of patients are men, and smoking, cardiovascular disease and old age are risk factors. Aim: The aim of the literature review was to describe people´s experiences of living with an aortic aneurysm. Method: The design is a qualitative literature review with an inductive approach. Result articles were searched on the databases CINAHL, PubMed and PsychInfo using relevant keywords for the topic. Manual searches were also performed. The produced articles were read using Friberg's 5-step model and analyzed on the basis of Graneheim and Lundman's qualitative content analysis. The analysis resulted in three main categories being selected with seven subcategories. Results:  Guidance in lived aortic aneurysm, Emotional aspects in lived aortic aneurysm and Life and daily living with aortic aneurysm were the three main categories which emerged in our analysis. With the subcategories Information from the healthcare, Knowledge about the diagnosis, Fear of the diagnosis, Thoughts about death, Future despite the diagnosis, Meeting the healthcare and Obstacles in everyday life. Information was what was most noticeable and over time, it turned out to be able to influence other subcategories both positively and negatively depending on quantity, delivery method and time. Conclusion: Through this literature review, the experiences turned out to be varied and these were individual depending on where in life the participant was and how life in general was for the participant. Further studies are needed to develop a more person-centred and individualized approach for people with aortic aneurysm.

Durante la pandemia COVID-19 se ha incrementado el uso de la telemedicina y de plataformas virtuales en el campo de la medicina, por ello en nuestra institución contamos con un sistema multicámara que permite la visualización en vivo de procedimientos endovasculares. Se realizaron once casos de aneurismas, malformaciones arteriovenosas y hematomas subdurales crónicos que fueron tratados y transmitidos en vivo sin problemas técnicos a través de la plataforma Zoom®. El tiempo promedio de transmisión y del número de participantes fue de 2.5 horas y 6 participantes, respectivamente. En todos los casos se discutió la técnica empleada y las complicaciones ocurridas. El aprendizaje remoto con plataformas en línea es hoy en día una herramienta importante, pero no un sustituto del aprendizaje práctico para procedimientos endovasculares. Recomendamos su implementación durante la pandemia de COVID-19 como un sustituto temporal, especialmente para los médicos en entrenamiento que no tienen acceso a intervenciones endovasculares avanzadas.

Percutaneous dilatational tracheostomy (PDT) has become an appropriate alternative to conventional surgical tracheostomy. It is now performed worldwide by a diverse array of physician specialists. Although adverse events are relatively uncommon, serious complications can arise from this bedside procedure. We report a patient who suffered life-threatening hemorrhage from a common carotid artery laceration and pseudo-aneurysm formation in the innominate artery following an elective PDT procedure.

Understanding the hemodynamics of the cardiovascular system and associated diseases is important for mitigating health risks. We applied flow diagnostic techniques to investigate pulsatile flow characteristics past sidewall cavities, which have implications to two biomedical problems in the cardiovascular system: sidewall aneurysms and the left atrial appendage. Superhydrophobically-coated mesh diverters and synthetic slippery surfaces were studied for their effects on flow diversion and cavity flow enhancements. The study of pulsatile flow over a coated mesh diverter showed that the formation of the primary vortex was prevented which prevents flow stagnation and downwash flow in the cavity. The second study indicates that the healthy heart cycle is essential to reducing flow stasis inside the left atrial appendage. After applying a synthetic slippery surface to the interior of a side wall cavity model, this surface reduced the wall shear stress and allowed vortical flow to reach deeper into the cavity.

La physiopathologie de l’anévrysme de l’aorte abdominale (AAA) est complexe. Elle implique notamment des facteurs hémodynamiques, une protéolyse matricielle, un stress oxydatif et une réaction immune. Des modèles expérimentaux ont été mis au point pour explorer les mécanismes impliqués dans la genèse et la croissance des AAAs. Dans ce travail, nous explorons le rôle de ces modèles dans la compréhension du remodelage vasculaire des AAAs. Dans une première partie, une revue de la littérature sur les modèles expérimentaux d’AAA est menée. Dans une seconde partie, nous explorons l’origine et le rôle des calcifications des AAAs expérimentaux. Dans une troisième partie, le modèle de xénogreffe aortique décellularisée est utilisé pour étudier le rôle de l’immunité adaptative dans la rupture. Notre revue identifie les principaux modèles d’AAA. Leur limite majeure est la survenue d’une cicatrisation empêchant l’évolution vers la rupture. Notre exploration des calcifications anévrysmales retrouve une co-localisation des calcifications avec de l’ADN libre et un modèle expérimental démontre la capacité de l’ADN libre à induire des calcifications. La croissance anévrysmale est toutefois ralentie par les calcifications. Notre étude sur le modèle de xénogreffe décellularisée retrouve la possibilité d’induire une rupture lorsqu’une pré-sensibilisation contre la matrice extracellulaire est réalisée. Les glycoprotéines de structure et les protéoglycanes semblent être les composants matriciels en cause dans ces ruptures. Les modèles expérimentaux constituent des outils majeurs pour l’étude des mécanismes impliqués dans le remodelage vasculaire des AAAs. / Pathophysiology of abdominal aortic aneurysms (AAA) is complex. It mainly involves hemodynamics, matrix proteolysis, oxidative stress and an immune reaction. Several experimental models have been described to explore mechanisms involved in this disease. In the present work, we explore the role of experimental models in AAA vascular remodeling. First, a literature review regarding experimental models of AAA is performed. Second, we explore the origin and the role of calcifications observed in experimental models. Third, the decellularized xenograft model is used to study the role of adaptive immunity in triggering rupture. Our review identifies main AAA models. Their major limit is aortic healing, preventing evolution toward rupture. We find that AAA calcifications co-localized with free DNA and that free DNA could induce calcifications experimentally. However, AAA growth is decreased by calcifications. The decellularized xenograft model can evolve toward rupture when pre-sensitization against the extracellular matrix is performed. Structural glycoproteins and proteoglycans seems to be the main matrix component involved in these ruptures. Experimental AAA models are major tools to study mechanisms involved in vascular remodeling.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20801号 / 医博第4301号 / 新制||医||1025(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 松田 道行, 教授 山下 潤, 教授 宮本 享 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13167号 / 論医博第2154号 / 新制||医||1029(附属図書館) / (主査)教授 宮本 享, 教授 小泉 昭夫, 教授 柳田 素子 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第21456号 / 社医博第90号 / 新制||社医||10(附属図書館) / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 滝田 順子, 教授 小杉 眞司, 教授 三森 経世 / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM

No description available.