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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Embolização arterial no traumatismo de bacia / Arterial embolisation on pelvic trauma

Guilherme de Palma Abrão 17 October 2008 (has links)
O trauma pélvico apresenta alta morbi-mortalidade, especialmente nos casos de dupla ruptura do anel pélvico (AP), devido à hemorragia. O objetivo deste trabalho é observar o tempo transcorrido até a realização do tratamento endovascular (TE), a sua eficácia e a estratégia de exames complementares empregado. 53 pacientes com fratura de bacia póstraumática foram submetidos a embolização arterial num estudo retro e prospectivo, realizado no período de janeiro de 2000 e dezembro de 2005. A idade dos pacientes variou entre 93 e 17 anos, com média de 37,5 anos. Houve predomínio do sexo masculino, com cerca de 62,2%. A causa do trauma mais freqüente foi o acidente de moto em 36% dos casos. Predominaram as fraturas com dupla ruptura do AP em 71,6 % dos casos. 49 pacientes apresentavam instabilidade hemodinâmica, e desses, todos receberam derivados sanguíneos previamente à realização do TE. Neste estudo 38,7% (n = 19) dos pacientes instáveis foram submetidos ao exame de tomografia computadorizada (TC) antes do TE, o tempo médio desse grupo para atingir a sala de radiologia vascular foi de 230,45 minutos. Nos pacientes enviados diretamente à arteriografia com intenção terapêutica, o tempo médio até início da realização do tratamento foi de 146,77 minutos. A diferença entre as taxas de mortalidade precoce nos grupos de pacientes submetidos ou não a TC previamente ao TE foi de 5,63%. O choque hemorrágico foi à causa de óbito em 63,33% dos pacientes que apresentaram mortalidade precoce. Na conduta inicial desses pacientes preconiza-se realizar o menor número de intervenções até o controle da hemorragia. O tempo transcorrido até a chegada na sala de radiologia vascular é fator importante no prognóstico dos pacientes com fraturas hemorrágicas da bacia. O TE precoce é uma importante ferramenta nos pacientes hemodinamicamente instáveis inicialmente / Pelvic trauma presents high morbi-mortality specially in cases of double rupture of pelvic ring due to hemorrhages. The objective of this work is to observe the time period since the rupture till the execution of endovascular treatment (ET) as well as the effectiveness and strategy for the used complementary exam. 53 patients with pos-traumatic pelvic fracture were submitted to arterial embolization during retro and prospective study. Such study was executed during the period of January 2000 to December 2005. The age of the patients varied between 17 and 93 years old, average 37.5 year old and predominantly men at about 62.2% of the cases. The most frequent cause of the traumas, 36%, was motorcycle accident. Predominantly fractures with double rupture of the pelvic ring, that is 71.6% of the cases. 49 patients presented hemodynamic instability, all of them received blood derivatives previously to the ET execution. In this study 38.7% (n=19) of the unstable patients were submitted to computerized tomography exam (CT) before the ET. The average period of time for this group to reach the room of vascular radiology was 230.45 min. For patients sent straight to arteriography with therapeutic intention, the average period time was 146.77 min. The difference, between the early mortality rate of the group undertaken or not to the CT previously to the ET, was 5.63%. The hemorrhagic shock was the cause of death in 63.33% patients, who presented early mortality. For the initial on going study of these patients, we recommend to accomplish the least number of interventions until hemorrhage is controlled. The elapsed time till the arrival at the vascular radiology room is an important factor to make prognosis about patients with hemorrhagic pelvic fractures. The early ET is an important tool for patients with hemodynamic instability
42

Avaliação da embolização de varizes periuterinas em pacientes com dor pélvica crônica secundária à síndrome da congestão pélvica / Evaluation of embolization of periuterine varices in patients with chronic pelvic pain secondary to congestion syndrome pelvic

Flavio Meirelles de Siqueira 11 July 2016 (has links)
Introdução: a dor pélvica crônica é um problema que afeta uma significativa parcela de pacientes que buscam atendimento ginecológico. Dentre suas etiologias, destaca-se a síndrome de congestão pélvica, causada por insuficiência venosa pélvica. A justificativa deste estudo foi verificar se a técnica endovascular pode ser considerada estratégia terapêutica efetiva e válida para a população brasileira. Objetivo: avaliar a resposta clínica e a taxa de sucesso após embolização de varizes periuterinas em pacientes com dor pélvica crônica secundária à síndrome de congestão pélvica, e relatar a segurança do tratamento endovascular e o índice de complicações. Materiais e métodos: coorte retrospectiva de pacientes submetidas a tratamento endovascular da síndrome de congestão pélvica em nosso serviço, no período de janeiro de 2012 até novembro de 2015. Foram analisados dados relativos aos antecedentes das pacientes, achados de exames de imagem, veias embolizadas, taxa de complicações e resposta clínica baseada na escala visual analógica de dor. Resultados: Foi realizada embolização de varizes periuterinas em 22 pacientes no período estudado, sendo que quatro delas realizaram uma segunda embolização. Foi observada redução da dor em 17 pacientes considerando-se a primeira embolização (77.3%) e em 3 pacientes na segunda embolização (75%). Foram observadas complicações menores em 5 pacientes, como hipotensão postural, dor no pós-operatório e perfuração venosa sem repercussão clínica durante o procedimento. Conclusão: O presente estudo apresentou resultados satisfatórios da embolização de varizes periuterinas na redução dos sintomas de pacientes com dor pélvica crônica secundária à síndrome de congestão pélvica, mostrando-se como método seguro. / Introduction: Chronic pelvic pain accounts a significant number of gynecologic referrals. Among its etiologies, there is the pelvic congestion syndrome, caused by pelvic venous insufficiency. The rationale of this study was to determine whether endovascular technique can be considered effective and valid therapeutic strategy for the Brazilian population. Objective: To evaluate the clinical response and the success rate after periuterine varices embolization in patients with chronic pelvic pain secondary to pelvic congestion syndrome, and report the safety of endovascular treatment and the rate of complications. Materials and methods: Retrospective cohort of patients undergoing endovascular treatment of pelvic congestion syndrome in our department from January 2012 to November 2015. Data were analyzed on the background of patients, imaging findings, embolized veins, rate complications and clinical response based on visual analog pain scale. Results: We performed peiruterine varices embolization in 22 patients during the study period, four of which held a second embolization. 17 patients reported a reduction in pelvic pain considering the first embolization (77.3%) and 3 patients in the second embolization (75%). Minor complications were observed in 5 patients, such as postural hypotension, postoperative pain and venous perforation during the procedure, without clinical repercussion. Conclusion: The present study showed satisfactory improvement of clinical symptons after periuterine varices embolization in patients with chronic pelvic pain secondary to pelvic congestion syndrome, showing up as a safe method.
43

Avaliação radiológica imediata, aos seis meses e aos 18 meses, do uso do copolímero etileno vinil álcool (Onyx®) no tratamento endovascular de aneurismas saculares intracranianos de colo largo / Radiological evaluation on immediate, 6 and 18 month control on the use of Onyx® in the endovascular treatment of wide neck intracranial aneurysms

Ronie Leo Piske 30 May 2008 (has links)
Introdução: A alta incidência de oclusão incompleta e recanalização dos aneurismas intracranianos de colo largo tratados por via endovascular levaram ao desenvolvimento de novas técnicas, entre elas o uso do Onyx ®. Objetivos: avaliar a eficiência do agente embólico líquido Onyx® em produzir oclusão completa dos aneurismas intracranianos de colo largo e avaliar a estabilidade do tratamento aos 6 meses e aos 18 meses, por meio de controles angiográficos. Casuística e métodos: Esta tese foi realizada na Seção de Neuroradiologia Intervencionista da Med Imagem, do Hospital São Joaquim da Real e Benemérita Associação Portuguesa de Beneficência de São Paulo, através da revisão de dados clínicos e radiológicos de 69 pacientes tratados pelo autor, com 84 aneurismas intracranianos de colo largo no período de julho de 2002 a fevereiro de 2006. Dez pacientes eram do sexo masculino e 59 do sexo feminino, com idade variando de 24 anos a 86 anos (mediana de 52 anos). Todos os aneurismas tinham origem lateral à artéria e apresentavam pelo menos um dos critérios usados para definir colo largo - colo maior que 4 mm de diâmetro e relação saco/colo menor que 1,5. Cinqüenta aneurismas eram pequenos, 30 grandes e quatro gigantes (diâmetro máximo menor que 12mm, de 12mm a 25mm e maiores que 25mm, respectivamente). As apresentações clínicas mais comuns foram: achado incidental em 34 pacientes, pós-hemorragia sub aracnóide e recanalização após tratamento com espirais destacáveis em 10. A maioria dos aneurismas era da artéria carótida interna (76 aneurismas). Controles angiográficos foram feitos ao final, aos seis meses e aos 18 meses do tratamento (controles I, II e III respectivamente), sendo analisados principalmente o grau de oclusão (completa ou incompleta), incidência de recanalização e complicações clínicas. Avaliação estatística foi feita pelo método de Kaplan-Meier para o percentual cumulativo de oclusão completa e percentual de recanalização e análise univariada e multivariada dos fatores preditivos de oclusão total imediata e tardia através de regressão logística. Resultados: O índice de oclusão completa foi de 65,5%, 84,6% e de 90,3% para todos os aneurismas, nos controles I, II e III respectivamente. Estes índices foram de 74%, 95,1% e de 95,2% para os aneurismas pequenos e de 53,3%, 70% e de 80% para os aneurismas grandes nos controles I, II e III respectivamente. Oclusão completa ocorreu em 50% dos aneurismas gigantes nos controles I e II, sem haver controle III neste grupo. Recanalização ocorreu em 3 aneurismas (4,6%). O porcentual cumulativo de oclusão completa foi de 97,63% (IC de 95% variando de 95,27 a 100) para os aneurismas pequenos aos 9 meses e de 83,86% (IC de 95% variando de 67,73 a 100) para os aneurismas grandes aos 21 meses. Três pacientes faleceram (4,3%), havendo relação com o procedimento em dois (2,9%). Morbidade permanente ocorreu em cinco pacientes (7,2%), sendo incapacitante em um (1,4%). Conclusões: 1. O uso do Onyx® foi eficiente na oclusão completa dos aneurismas intracranianos de colo largo. 2. O tratamento foi estável nos controles angiográficos aos 6 meses e aos 18 meses. / Introduction: The high rate of incomplete occlusion and intracranial large neck aneurysms recanalization lead to the development of new techniques, including the use of Onyx®. Purpose: to evaluate the efficacy of the liquid embolic system Onyx ® to produce completes occlusion of the intracranial large neck aneurysms and evaluates the stability of the treatment at 6 month and 18 month angiographic control. Materials and Methods: this thesis has been performed at Section of Interventional Neuroradiology of Med Imagem, at the Hospital São Joaquim da Real e Benemérita Associação Portuguesa de Beneficência de São Paulo, based on a review of clinical and radiological records of 69 patients treated by the author, harboring 84 large neck intracranial aneurysms between July 2002 and February 2006. Ten patients were male and 59 female, with age ranging from 24 to 86 years old. All aneurysms were lateral to the parent vessel and were wide neck (neck > 4 mm and/or domus to neck ratio < 1.5). Fifty aneurysms were small (<12 mm), 30 were large (12 to 25 mm) and 4 were giant (> 25 mm). Thirty four aneurysms were incidental, 10 were ruptured and 10 were recanalized after coil treatment and the majority was located in the internal carotid artery (76). Angiographic follow-up was done at the end of the procedure, at six month and at 18 month (controls I, II and III respectively), analyzing the rate of complete occlusion, recanalization and clinical complication. Statically analysis were done by Kaplan-Meier method for cumulative percentage of complete aneurysm occlusion and for recanalization, and univariate and multivariate analysis of predictive factors of immediate and late complete occlusion through logistic regression. Results: Complete aneurysm occlusion was achieved in 65.5% on immediate control, in 84.6% at 6 month, and in 90.3% at 18 month follow-up periods for all aneurysms. This rate was 74%, 95.1% and 95.2% for small and 53.3%, 70% and 80% for large aneurysms at the same follow-up periods. In the giant aneurysm group, two had complete and stable occlusion at six month follow-up angiography. Recanalization was seen in three aneurysms (4,6%). Kaplan Meyer\'s cumulative percentage of complete aneurysm occlusion was 97.63% (CI 95% ranging from 95,27 to 100) for small aneurysms at 9 months and 83.86% (CI 95% ranging from 67,73 to 100) for large aneurysms at 21 months. There were three deaths (4,3%), two procedure-related (2.9%). Overall morbidity was 7.2%, being disabling in one (1,4%). Conclusions: 1. The use of Onyx was efficient in the complete occlusion of wide neck intracranial aneurysms. 2. The treatment was stable at 6 month and 18 month angiographic controls.
44

Resultados do tratamento radiocirúrgico de doentes com malformações arteriovenosas encefálicas classificadas como graus 3A, 3B, 4 ou 5 previamente submetidos ou não à embolização / The results of radiosurgical treatment of grade 3A, 3B, 4 and 5 cerebral arteriovenous malformations previously treated or not with embolization

Evandro César de Souza 04 May 2010 (has links)
Introdução: O risco do tratamento das malformações arteriovenosas encefálicas (MAVEs) é proporcional à sua graduação. O processo de seleção da técnica empregada depende, além da natureza e localização das MAVEs, das condições clínicas e idade dos doentes e da disponibilidade de profissionais treinados e de equipamentos apropriados no ambiente onde o doente é tratado. Objetivo: Avaliar a eficácia da radiocirurgia e da embolização prévia ao tratamento radiocirúrgico das MAVEs classificadas como graus 3A, 3B, 4 ou 5. Métodos e Resultados: O trabalho baseou-se na observação retrospectiva de prontuários clínicos e de arquivos de imagens de 90 doentes com diagnóstico de MAVEs classificadas como graus 3A, 3B, 4 ou 5 submetidos a tratamento com radiocirurgia precedida ou não de embolização no Departamento de Radioterapia e Radioterapia Estereotáctica, Neuroradiologia Intervencionista e Neurocirugia da Real e Benemérita Associação Portuguesa de Beneficência de São Paulo, de outubro de 1993 a outubro de 2008. As idades dos doentes variaram de sete a 60 anos (média de 30,6 anos ± 11,59 anos, mediana de 28 anos). Eram do sexo feminino 46 (51,1%) doentes. Todos foram submetidos a três exames de ressonância magnética (RM) ou tomografia computadorizada (TC) no primeiro ano de acompanhamento e a um exame de RM ou TC do encéfalo no segundo e terceiro anos. Quando um dos exames sugeriu oclusão da MAVE ou o período de acompanhamento foi maior que três anos, os doentes foram submetidos à angiografia digital do encéfalo. Em 51 (56,7%) dos 90 doentes tratados ocorreu oclusão completa da MAVE após a primeira radiocirurgia (1ª Rc), em 21 (23,3%) foram evidenciadas complicações clínica em 36 (40,0%), foram visibilizadas anormalidades no exame de RM. Em 30 (33,3%) doentes evidenciou-se hipersinal no encéfalo em T2 na RM xvi e, em seis (6,7%), radionecrose. Trinta e dois(82,0%) dos 39 doentes que não apresentaram oclusão completa da MAVE após a 1ª Rc foram submetidos à segunda radiocirurgia (2ª Rc). Ocorreu oclusão completa em 12 (37,5%) destes doentes, instalaram-se complicações clínicas em cinco (15,6%) e, anormalidades no exame de RM em oito (25,0%), ou seja, hipersinal em T2 na RM em três (9,5%) e radionecrose em cinco (15,6%). Conclusão: Concluiu-se que a radiocirurgia foi eficaz no tratamento das MAVEs graus 3A, 3B, 4 e 5, que as MAVEs classificadas como grau 3B devem tratadas, preferencialmente, apenas com radiocirurgia e que as MAVEs classificadas como 3A, 4 e 5 devem ser submetidas à embolização previamente à radiocirugia para reduzir-se sua graduação e seu fluxo sanguíneo / Introduction: The risk of treatment of the cerebral arteriovenous malformations (AVM) is proportional to their grade and is affected by the method used. The selection of the AVM therapeutic method depends of the vascular pattern and anatomical site, clinical condition and age of the patient, experience of the treating team and of the equipment available. Objectives: This study aimed the evaluation of the efficacy of the radiosurgical treatment of Grade 3A, 3B, 4 and 5 cerebral AVMs in patients previosly treated or not with embolization. Methods and Results: The data of the clinical notes and the computed tomography (CT) and magnetic ressonance (RM) images of the brain of 90 patients with Grade 3A, 3B, 4 or 5 cerebral embolised or not AVMs treated with radiosurgery at the Department of Radiotherapy, Stereotactic Radiotherapy, Interventional Neuroradiology and Neurosurgery at Real e Benemerita Associação Portuguesa de Beneficência de São Paulo were retrospectively reviewed. The ages of the patients ranged from 7 to 60 years of (average = 30.6 ± 11.59 years; median = 28 years) and 46 (51.1%) were female. During the first year after treatment three MR or CT scans of the brain were evaluated and one at the end of the 2nd and 3rd years after the treatment one MR or CT scan were re-evaluated respectively. When the brain scans suggest AVM occlusion, cerebral angiography was performed. In 51 of the 90 patients (56.7%) there was complete occlusion of the AVM after one radiosurgical treatment; 21 of the patients (23.3%) had clinical complications. In 36 patients (40.0%) new abnormalities of the MR became evident. Thirty (33.3%) presented T2 hypersignal and six (6.7%), had radionecrosis. From the 39 patients who did not had complete occlusion of the AVM, 32 (82.0%) had a second radiosurgical course of treatment; in 12 xviii (37.5%) the AVM became completely occluded but five (15.6%) had clinical complications. Eight (25.0%) of these patients presented new abnormalities at the MR scan of the brain; three (9.5%) had T2 hypersignal and five (15.6%) radionecrosis. Conclusions: Radiosurgery was effective in the treatment of Grade 3A, 3B, 4 and 5 cerebral AVMs , Grade 3B cerebral AVM should be treated only with radiosurgery without previous embolization, and Grade 3A, 4 and 5 AVMs should be treated with embolization to reduce their AVM grade and blood flow prior to radiosurgery
45

In vitro characterization of cyanoacrylate embolic glues used for vascular embolization / Caractérisation in vitro de colles emboliques cyanoacrylates utilisées pour l'embolisation vasculaire

Li, Yongjiang 18 April 2017 (has links)
L’embolisation vasculaire est un traitement peu invasif utilisé pour éliminer ou interrompre de façon sélective les apports vasculaires à des régions spécifiques du corps. Une technique consiste en l’introduction d’un microcathéter dans le vaisseau sanguin cible et à administrer un agent embolique qui réagit au contact du sang. Les colles emboliques à base de cyanoacrylate sont les principaux agents liquides utilisés pour l’embolisation à cause de leur faible viscosité, leur bonne capacité de pénétration et leur faible toxicité tissulaire. Pour permettre sa détection après injection, la colle est mélangée à un agent de contraste radio-opaque telle que l’huile iodée Lipiodol®. Bien que la technique soit couramment utilisée, il existe peu de données sur la dynamique du processus d’injection au sein de flux sanguins complexes ou sur la cinétique de polymérisation du mélange colle-Lipiodol. Par conséquent, une occlusion sans danger est difficile à réaliser, même entre les mains de radiologues expérimentés. Le principal objectif de la thèse est d’étudier de façon quantitative les propriétés physiques et la cinétique de polymérisation des colles cyanoacrylates mélangées au Lipiodol dans différentes proportions. Nous avons conçu un nouveau dispositif expérimental pour caractériser le processus de polymérisation d’un mélange colle/Lipiodol en contact avec une solution ionique ou protéinée. Les résultats montrent un processus de polymérisation rapide à l’interface entre la colle et le substrat, suivi par la proagation d’un front de polymérisation dans le volume de préparation de colle. Les constantes de temps des processus dépendent des compositions de la solution et du mélange de colle. Un autre objectif est d’analyser le processus d’embolisation dynamique. Un modèle in vitro du processus d’injection est utilisé pour étudier en premier lieu la formation de goutte entre deux flux immiscibles et qui ne réagissent pas entre eux. L’injection d’une préparation de colle dans une solution ionique en écoulement est ensuite réalisée pour montrer l’influence conjointe de la polymérisation et de l’hydrodynamique. C’est la première fois qu’une telle caractérisation exhaustive de colles emboliques à base de cyanoacrylate est obtenue. Les résultats peuvent apporter des informations cruciales aux radiologues interventionnels, ce qui les aidera à comprendre et contrôler le comportement de la colle après injection afin d’accomplir une oblitération permanente des vaisseaux en toute sécurité. / Vascular embolization is a minimally invasive treatment used to selectively eliminate or stop the vascular supply to specific body areas. One technique consists of navigating a microcatheter into the targeted blood vessel and injecting an embolic agent which reacts in contact with blood. Cyanoacrylate-based embolic glues are the main liquid adhesives used for vascular embolization owing to their low viscosity, good penetration ability and low tissue toxicity. To enable its detection once injected, the glue is mixed with a radio-opaque contrast agent such as the Lipiodol iodized oil. Although the technique is commonly used, there is very little information on the dynamics of the injection process in complex blood flows or on the polymerization kinetics of the glue-Lipiodol mixture. Consequently, safe occlusion is difficult to achieve, even in the hands of experienced radiologists. The main objective of the thesis is to quantitatively investigate the physical properties and polymerization kinetics of cyanoacrylate glues mixed with Lipiodol in different proportions. We have designed a new experimental setup to characterize the polymerization process of a glue/Lipiodol mixture on contact with an ionic or proteinaceous solution. We find that there is a fast polymerization process at the interface between the glue and the substrate, followed by the propagation of a polymerization front in the glue mixture volume. The time constants of the processes depend on the solution and glue mixture compositions. Another objective is to analyze the dynamic embolization process. An in vitro model of the injection process is used to first investigate the drop formation between two non-reacting immiscible flows. The injection of a glue mixture into a flowing ionic solution is then performed to show the joint influence of polymerization and hydrodynamics. It is the first time that such comprehensive characterization of cyanoacrylate-based embolic glues is acquired. The results can provide crucial information to interventional radiologists, that will help them understand and control the glue behavior after injection to achieve a safe and permanent obliteration of the vessels.
46

L'utilisation des agents d'embolisation liquides dans les vaisseaux périphériques : mise au point, défis et futures perspectives : preuves de concept d'un nouvel agent sclero-embolique : Alconyx / The use of liquid embolic agents in peripheral vessels : current status, challenges and future perspectives : proof of concept of a new sclero-embolic agent Alconyx : Alconyx

Saeed Kilani, Mohammad Ali 07 December 2016 (has links)
Les agents d'embolisation liquides utilisés dans le traitement endovasculaire ont de nombreuses limitations. Des polymères, tels que l’Onyx et les cyanoacrylates sont disponibles. L’alcool est un agent puissant, mais non radio-opaque. Les cyanoacrylates entrainent une réaction inflammatoire significative. Leur polymérisation rapide est responsable d’un comportement mal prévisible.Il existe une possibilité de traitement incomplet.L’Onyx est efficace pour le traitement des MAV.Une pénétration plus distale est obtenue avec l’alcool, mais associée à un risque de migration systémique. Nous avons évalué les propriétés d'un nouvel agent embolique (Alconyx) composé d'un mélange d'alcool et d'Onyx. Cet agent devrait cumuler les avantages respectifs de l'alcool et de l'onyx avec une visualisation adéquate sous fluoroscopie, une meilleure pénétration distale que l'Onyx seul et moins de toxicité systémique liée à la réduction de quantité d’alcool injecté. Divers mélanges ont été testés avec différentes concentrations d'Onyx 18 et d’alcool absolu. Alconyx 25 (75% Onyx 18; 25% d'éthanol) est la formulation la plus prometteuse. Nous avons démontré sa facilité d'injection in vivo, sa nature cohésive sans fragmentation ainsi que sa bonne visualisation sous fluoroscopie. En raison de sa moindre viscosité démontrée in vitro, Alconyx a été capable de pénétrer profondément dans le lit artériel.. L'occlusion proximale par Alconyx 25 devrait permettre d'améliorer le contact entre l'éthanol et la paroi vasculaire et donc augmenter son pouvoir sclérosant et limiter son passage systémique. Les propriétés occlusives d’Alconyx 25 sont similaires à celle de l’Onyx 18 sous haute pression in vitro. / Commercially available liquid embolization agents used in endovascular treatment have many limitations. Polymeric agents as Onyx and cyanoacrylate are available. Ethanol also is a potent sclero-embolic agent. Cyanoacrylates are effective liquid embolic agents, however, their rapid polymerization makes their behaviour unpredictable with possibility of incomplete treatment. These properties render their use challenging.Onyx is easy to use. However, in very small arterial niduses, Onyx, is unable to penetrate deeply. Deep penetration is obtained with ethanol, associated with risk of systemic migration.Poor visualization of ethanol under fluoroscopy is major drawback. Mixing Onyx with ethanol had never been described in the literature till now. In this work, various mixtures have been tested with different concentrations of Onyx 18 and absolute ethanol. Alconyx 25 (75% Onyx 18; 25% ethanol) seems to be a promising product. We proved its ease of injection in vivo and in vitro, its cohesive nature showing no fragmentation or interruption of the injected column as well as its good visualization under fluoroscopy. It was able to penetrate deeply in the arterial bed. The occlusive properties of Alconyx 25 were rated as good as Onyx 18 under high pressure in vitro. Further investigation is needed to better understand the behavior of ethanol in the suspension and its effect on tissues compared to Onyx diluted simply with an equivalent amount of DMSO. Studies on other commercially available concentrations of Onyx would certainly be interesting.
47

L'embolisation portale résorbable répétée : stimulus de la régénération hépatique / Repeated resorbable portal vein embolization : stimulating liver regeneration

Gaillard, Martin 10 December 2019 (has links)
Le foie possède une capacité de régénération importante qui lui permet de reconstituer son volume suite à une agression. L’induction d’une régénération hépatique est réalisée en pratique courante en chirurgie hépatique afin de préparer le foie à une hépatectomie majeure. Elle est également utilisée dans de nombreux modèles animaux afin de favoriser la prise de greffe hépatocytaire au cours de la transplantation d’hépatocytes pour le traitement de maladies métaboliques héréditaires hépatiques. Les principaux objectifs de ce travail ont été d’étudier une méthode peu invasive pour induire une importante régénération hépatique : d’une part pour élargir les possibilités de prise en charge des patients nécessitant une hépatectomie, et d’autre part pour favoriser la prise de greffe des hépatocytes transplantés pour le traitement des maladies métaboliques héréditaires hépatiques.Dans un premier temps, nous avons mis au point chez le rat une technique d’embolisation portale partielle résorbable répétée (EPPRR) visant à entrainer un stimulus additionnel de régénération hépatique. Ces travaux ont validé le concept de la méthode d’EPPRR en montrant une augmentation de la prolifération hépatocytaire et une hypertrophie dans la partie du foie non embolisée.Ce protocole d’EPPRR a ensuite été appliqué dans un modèle préclinique de gros animal. Nous avons étudié chez le porc les conséquences de l’EPPRR et montré que cette technique était reproductible, bien tolérée, et qu’elle permettait une hypertrophie de la partie du foie non embolisée.Parallèlement, nous avons appliqué l’EPPRR avant transplantation d’hépatocytes chez le rat. A partir du foie de rats transgéniques exprimant la GFP (green fluorescent protein), nous avons pu isoler des hépatocytes GFP+. Ces cellules ont été transplantées dans le foie de rats receveurs GFP- en association avec une EPPRR. Nous avons montré que le stimulus de régénération répété provoqué par l’EPPRR permettait une augmentation de la prise de greffe.En conclusion, l’EPPRR est une technique peu invasive capable d’induire une régénérative hépatique efficace. Cette approche pourrait jouer un rôle dans la prise en charge des tumeurs hépatique et l’optimisation de la transplantation d’hépatocytes pour le traitement des maladies métaboliques héréditaires hépatiques. / The liver has an important regenerative capacity allowing reconstitution of the hepatic volume after an aggression. The induction of liver regeneration is used in routine clinical practice before liver surgery in order to prepare the liver for major hepatectomy. It is also used in numerous animal models in order to increase hepatocyte engraftment during hepatocyte transplantation for the treatment of inherited metabolic liver diseases. The main objective of this work was to evaluate a minimally invasive approach to induce substantial liver regeneration: firstly, to expand the therapeutic options for patients requiring an hepatectomy, and secondly to increase the engraftment of transplanted hepatocytes for the treatment of inherited metabolic liver diseases.In a first study, we developed in the rat model a technique of repeated reversible portal vein embolization (RRPVE) to induce an additional stimulus of liver regeneration. This study established the proof of concept of the RRPVE method, showing an increase in hepatocyte proliferation and hypertrophy in the non-embolized liver.This RRPVE protocol was then used in a preclinical model of large animal. We studied in swine the consequences of the RRPVE and showed that the procedure was reproducible, well tolerated, and allowed hypertrophy of the non-embolized liver.In parallel, we applied RRPVE before hepatocyte transplantation in the rat model. From the liver of transgenic rats expressing GFP (green fluorescent protein), we were able to isolate GFP+ hepatocytes. These cells were transplanted in the liver of recipient GFP- rats in association with RRPVE. We demonstrated that the repetition of the regeneration stimulus induced by RRPVE allowed increased hepatocyte engraftment.In conclusion, RRPVE is a minimally invasive technique able to induce efficient liver regeneration. This approach could play a part in the management of hepatic malignancies and the optimization of hepatocyte transplantation in the treatment of inherited metabolic liver diseases.
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Multi-Processor Computation of Thrombus Growth and Embolization in a Model of Blood-Biomaterial Interaction Based on Fluid Dynamics

Andersen, Brandon Thomas 21 April 2012 (has links) (PDF)
This work describes the development and testing of a real-time three-dimensional computational fluid dynamics simulation of thrombosis and embolization to be used in the design of blood-contacting devices. Features of the model include the adhesion and aggregation of blood platelets on device material surfaces, shear and chemical activation of blood platelets, and embolization of platelet aggregates due to shear forces. As thrombus develops, blood is diverted from its regular flow field. If shear forces on a thrombus are sufficient to overcome the strength of adhesion, the thrombus is dislodged from the wall. Development of the model included preparing thrombosis and embolization routines to run in a parallel processing configuration, and estimating necessary parameters for the model including the adhesion strength of platelet conglomerations to the device surfaces and the criterion threshold for the coalescence of neighboring thrombi. Validation of the model shows that the effect of variations in geometry may be accurately predicted through computational simulation. This work is based on previous work by Paul Goodman, Daniel Lattin, Jeff Ashton, and Denzel Frost.
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Désendothélialisation des anévrismes lors du traitement endovasculaire : une nouvelle approche pour prévenir les endofuites

Bonneviot, Marie-Christine January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
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Avaliação clínica e técnica do tratamento endovascular percutâneo na síndrome da congestão pélvica através da técnica de embolização / Clinical and technical evaluation of transcatheter embolotherapy of the pelvic congestion syndrome

Nasser, Felipe 26 March 2007 (has links)
Um conjunto de evidências sugere que a síndrome da congestão pélvica está associada às varizes pélvicas. A congestão pélvica é explicada em muitos casos pela insuficiência das veias ovarianas em drenar o fluxo venoso dos ovários. No presente estudo, realizou-se a avaliação clínica e técnica do tratamento endovascular percutâneo na síndrome da congestão pélvica através da técnica de embolização. Foram tratadas 113 mulheres, das quais 100 foram acompanhadas pelo período de um ano e a análise dos resultados foi baseada nessa amostra. Os resultados clínicos foram baseados na avaliação da sintomatologia durante o período de acompanhamento, com a utilização da escala visual analógica. A avaliação técnica baseou-se no sucesso da realização dos procedimentos e na avaliação das complicações. As pacientes selecionadas com diagnóstico clínico da síndrome foram submetidas ao estudo angiográfico que revelou insuficiência das veias ovarianas previamente ao tratamento por embolização. Obteve-se sucesso técnico em todos os casos, caracterizado pela possibilidade de realização do cateterismo seletivo das veias ovarianas e ilíacas internas com embolização das mesmas. A remissão total dos sintomas foi observada em 37 pacientes (32.7%) e parcial em 63 pacientes (55.4%). Foi observado significativo alívio dos sintomas (p < 0,001), confirmados pela redução dos valores obtidos através da escala analógica visual. A principal complicação foi a migração do agente embolizante metálico, no entanto, com resolução endovascular de todos os casos e sem repercussão clínica. O tratamento endovascular das varizes pélvicas por meio da embolização apresentou resultados satisfatórios em relação aos sintomas apresentados e mostrou-se como método seguro e com baixos índices de complicação. / A great body of evidence suggests that the pelvic congestion syndrome is associated to female varicocile. Pelvic congestion is explained in many cases by ovarian and internal iliac vein insufficiency. The endpoint of the study was the measurement of clinical outcomes and technical success of transcatheter embolotherapy in order to obtain relief of symptoms. The treatment group included 113 patients but only 100 were submitted for a follow up period. We had initial technical success rate of the ovarian and internal iliac vein embolization in all cases. It was used a visual analog scale (VAS) during the 12 months follow up period. The selected patients with the diagnosis of the syndrome were submitted to an angiographic evaluation to reveal ovaric and internal iliac vein insufficiency previous embolization. The technical success was determined by the ability to successfully embolize the ovarian and internal ilac varices and the clinical evaluation by the improvement of symptoms after the following period. A total relief of symptoms was observed in 37 patients (32.7%) and partial relief in 63 (55.4%). Nevertheless, it was seen an important general relief of every symptom (p < 0.001), as well a reduction of the values. The main complication was coil distal embolization, nevertheless, all of them were solved by endovascular approach without clinical repercussion. The transcatheter embolotherapy of the pelvic congestion syndrome provides significant symptomatic improvement, initial technical success and showed no significant long-term complications.

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