Academic literature on the topic 'TAVI'

Le remplacement valvulaire aortique percutané (TAVI) est une thérapie qui s’impose de plus en plus chez les patients porteurs d’une sténose aortique sévère. Toutefois, un nombre croissant d’études démontre que l’utilisation, crimping (sertissage) et déploiement, de ces bioprothèses est induit une altération de la structure de leurs feuillets péricardiques. Ce qui soulève la question de la durabilité à long-terme de ces dispositifs.Dans les travaux de cette thèse, nous avons développé des outils permettant d’analyser le traumatisme subi par les feuillets de péricardes.La première stratégie visait à déterminer les différences de comportements des péricardes bovins et porcins en matière de diffusion vis à vis de différents solutés. Nous avons pu mettre en évidence que la perméabilité du péricarde porcin était plus élevée (en moyenne 5-fois) et plus hétérogène comparativement à celle du péricarde bovin. La seconde stratégie consistait à caractériser, à l’aide des outils développés, les lésions traumatiques induites lors du déploiement des prothèses auto-expansible ou déployable par inflation d’un ballon. Quelque soit le type de prothèses utilisées, une altération de la perméabilité membranaire des péricardes a été observée après leurs déploiements.La dernière stratégie était de déterminer si le crimping de bioprothèses auto-expansibles pouvait entrainer une calcification plus importante des feuillets péricardiques. Un modèle d’évaluation de la calcification in-vivo chez le lapin a été utilisé. Cette étude à permis d’observer que le taux de calcium ainsi que la minéralisation du péricarde n’étaient pas affectées par le crimping<br>Transcatheter aortic valve replacement (TAVR) is a growing therapy indicated to treat severe aortic valve stenosis. However, an increasing number of studies demonstrated that crimping and deployment of these bioprostheses induce structural alterations of the pericardial leaflets. These observations raise interrogations concerning the long-term durability of these devices.In this thesis works, we developed tools to analyze pericardial leaflets injuries.The first strategy consisted to determine the differences between bovine and porcine pericardium toward the filtration of various solute.It was possible to observe that porcine pericardium hydraulic conductance was higher (5-folds) and more heterogeneous than bovine pericardium.The second strategy consisted to characterize the lesions induced by deployment of self and balloon expandable valved-stents.After deployment, both types of valved-stents showed an alteration of their pericardial hydraulic conductance.The last strategy was to determine if self-expandable valved-stents crimping could increase their pericardial leaflets calcification. The rabbit model was used as an in-vivo evaluation model.This study showed that the calcium concentration and the mineralization of their pericardial leaflets were unaffected by valved-stents crimping

Taustaa: TAVI (transcatheter aortic valve implantation)-toimenpide on perinteistä aorttaläppäleikkausta mini-invasiivisempi operatiivinen vaihtoehto oireisen aorttaläpän stenoosin hoidossa. Aineisto ja menetelmät: Tutkimme retrospektiivisesti marraskuun 2011 ja syyskuun 2015 välisenä aikana TAVI:lla hoidettujen (n=123) potilaiden päätetapahtumien esiintyvyyttä. Vertailuaineistona toimii ikävakioidut perinteisellä aorttaläppäleikkauksella hoidetut potilaat (n=68). Tulokset: Sairaalakuolleisuudessa ei todettu eroa TAVI:lla ja AVR:lla hoidettujen potilaiden välillä. Verisuonikomplikaatioita esiintyi merkittävästi enemmän TAVI-ryhmässä ja RIFLE-luokituksen mukaista akuuttia munuaisten vajaatoimintaa kehittyi merkittävästi useammalle AVR-ryhmässä. Komplikaatioita kehittyi vähemmän transfemoraalista reittiä hyödyntäen kuin muilla TAVI-tekniikoilla. Pohdinta: OYS:ssa TAVI:lla hoidettujen potilaiden hoidon tulokset komplikaatioiden esiintyvyys ovat samaa tasoa kuin kansainvälisissä tutkimuksissa on aiemmin esitetty. Olennaiset hoidon lopputulemat ovat samankaltaiset TAVI:lla ja perinteisen läppäkirurgia välillä.

La prise en charge du rétrécissement aortique a connu une véritable révolution avec l’avènement du remplacement valvulaire aortique percutané (TAVI). Cette technique, s’adressant initialement à des patients à haut risque chirurgical, a été étendue à des patients à moindre risque du fait de l’amélioration des résultats et s’est accompagnée, au fil des années, d’une simplification de la procédure. Cependant, la sélection rigoureuse des patients en amont de la procédure reste la clé du succès de cette technique. Les facteurs cliniques et échographiques sont insuffisants pour permettre une évaluation précise du profil de risque. Certains biomarqueurs et les calcifications de la valve aortique, permettraient d’améliorer la stratification du risque. L’objectif de ce travail était d’évaluer la valeur pronostique de la troponine et du score calcique valvulaire dans le TAVI à l’ère de l’évolution des pratiques. Le premier chapitre de cette thèse a permis de confirmer la valeur pronostique de la troponine en pré et post-procédure TAVI et celle du score calcique avec les valves de la précédente génération. Le deuxième chapitre de ce travail a permis de mettre en évidence l’impact de la prédilatation sur l’élévation de troponine post-procédure avec un rôle pronostique potentiel<br>Management of aortic stenosis was revolutionized by the advent of transcatheter aortic valve replacement (TAVI). This technique, initially targeting patients at high surgical risk, was extended to lower risk patients regarding to improved outcomes and was accompanied, over the years, by a simplification at each step of the procedure. However, the careful selection of patients upstream of the procedure remains the key to success. Clinical and echographic factors are not sufficient to allow an accurate assessment of their risk profile. Thus, biomarkers and aortic valve calcifications evaluation may improve risk profile stratification. The objective of this thesis was to evaluate the prognostic value of troponin and aortic valve calcium score in patients undergoing TAVI in the era of TAVI simplificationThe first chapter of this thesis confirmed the prognostic value of pre- and post-procedure troponin (myocardial injury) in patients undergoing TAVI and of calcium score with previous generation prosthesis.The second chapter highlighted the impact of predilatation on this post-procedure troponin elevation with a potential prognostic impact

Aortic stenosis is a life-threatening valvular heart disease. At the onset of symptoms, a patient’s prognosis becomes poor and the risk of death rapidly increases. Aortic valve replacement surgery remains the gold standard in treatment for aortic stenosis. However, in the total population of patients with severe aortic stenosis, about one third are deemed inoperable due to their high surgical risk. In recent years, the development of transcatheter aortic valve implantation (TAVI), a non-invasive heart valve replacement procedure brought hope for the elderly, high-risk and inoperable aortic stenosis patient population pool. A literature review was performed to examine the safety, efficacy and effectiveness evidence for transcatheter aortic valve treatment option. The results showed that TAVI is a safe treatment option, however the effectiveness for the whole patient population is unknown. The adoption of this alternative treatment option is certainly coupled with multiple dimension of impact from a public health perspective. It remains inconclusive whether TAVI is an effective treatment option to be adopted.<br>published_or_final_version<br>Public Health<br>Master<br>Master of Public Health

Mestrado em Tecnologias da Imagem Médica<br>Introdução: A implantação de válvula aórtica percutânea (IVAP) tornou-se uma alternativa terapêutica de sucesso em doentes com estenose aórtica grave sintomática, considerados inoperáveis ou de risco cirúrgico proibitivo. Lesão renal aguda e eventos neurológicos são complicações frequentes após o mesmo, e admite-se que possam estar envolvidos fenómenos de ateroembolismo com origem na aorta torácica. O objetivo do presente estudo foi investigar a existência de uma associação entre a carga aterosclerótica, avaliada por TCMD, e a ocorrência de LRA e eventos neurológicos após IVAP. Métodos: Foram selecionados 215 pacientes (idade média 79.0±8.43; 47.9% sexo masculino) que realizaram o procedimento por via transfemoral, com exame de TCMD no sistema. A aorta torácica foi anatomicamente dividida em aorta ascendente, arco aórtico, e aorta descendente, sendo esta última subdividida entre 5 a 8 segmentos de acordo com as artérias intercostais. Os segmentos com uma espessura da íntima ≥ 2mm foram classificados como envolvidos por aterosclerose. A carga aterosclerótica foi determinada com base na proporção de segmentos da aorta torácica afetados, assim como a espessura máxima das placas de ateroma. Os índices de aterosclerose avaliados por TCMD foram correlacionados com a ocorrência de LRA e AVC/AIT utilizando um modelo de regressão logística multivariada. Resultados: Verificaram-se 51 (23.7%) casos de LRA e 17 (7.9%) eventos neurológicos. O modelo de regressão logística multivariada demostrou uma aparente relação entre a espessura máxima de placa na AoD e LRA, mas nenhuma associação entre carga aterosclerótica e eventos neurológicos. Conclusão: A ocorrência de LRA aparenta estar associada à presença de aterosclerose na AoD. Não foi possível retirar conclusões relativas a eventos neurológicos.<br>Background: Transcatheter Aortic Valve Implantation (TAVI) has become a successful alternative therapy in patients with symptomatic severe aortic stenosis deemed inoperable or with prohibitive surgical risk. Acute kidney injury and neurological events are frequent complications after the procedure, and it is assumed that may be involved atheroembolism phenomena originating in the thoracic aorta. The aim of this study was to investigate the possibility of an association between atherosclerotic burden, assessed by MDCT, and the occurrence of AKI and neurological events after TAVI. Methods: We selected 215 patients (mean age 79.0 ± 8.43; 47.9% male) who underwent a transfemoral approach of the procedure, with MDCT examination in the system. The thoracic aorta was anatomically divided into the ascending aorta, aortic arch and descending aorta, the latter being subdivided into 5 to 8 segments according to the intercostal arteries. The segments with a intimal thickness ≥ 2mm were classified as involved in atherosclerosis. The atherosclerotic load is determined based on the proportion of segments of thoracic aorta affected, as well as the maximum thickness of the atheromatous plaques. Atherosclerotic indices evaluated by MDCT were correlated with the occurrence of AKI and stroke / TIA using a multivariate logistic regression model. Results: We found 51 (23.7%) cases of AKI and 17 (7.9%) neurological events. The multivariate logistic regression model demonstrated an apparent relationship between the maximum thickness plate in the descending aorta and AKI, but no association between atherosclerotic burden and neurological events. Conclusions: The presence of AKI appears to be associated with the presence of atherosclerosis in the descending aorta. It was not possible to draw conclusions on the neurological events.