Thesis--University of Alexandria, 1962. / Summary in Arabic. Includes bibliographical references (p. 97-99).

Thesis--University of Alexandria, 1962. / Summary in Arabic. Includes bibliographical references (p. 97-99).

Orientador: Fabio Husemann Menezes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-14T03:12:56Z (GMT). No. of bitstreams: 1 Rielli_Glauber.pdf: 567843 bytes, checksum: 4d042894d00f11bcc831e52dc91eb94b (MD5) Previous issue date: 2009 / Resumo: Objetivo: Avaliar em suínos a viabilidade, morbidade e mortalidade imediata do acesso vascular alternativo para hemodiálise através da punção da veia ázigos, guiada por vídeo-toracoscopia. Material e métodos: Oito suínos foram submetidos a punção da veia ázigos e posterior introdução do cateter de hemodiálise na posição central através de vídeo-toracoscopia em hemitórax esquerdo, com ligadura distal e reparo proximal da mesma com dupla laçada de fio de silicone para hemostasia para quando da retirada do cateter. Os animais foram monitorizados através de dados hematimétricos, gasometria, pressão invasiva e sacrificados ao final. Resultados: Em cinco animais o procedimento transcorreu semintercorrências, com fluxo adequado pelo cateter, sem hemorragia, em um tempo médio de duas horas. Em dois animais houve a necessidade de dissecção direta da veia ázigos através da conversão para toracotomia devido a perda do controle hemostático. Em um destes animais houve lesão do parênquima pulmonar sem comprometer a ventilação. Em um animal a veia não foi localizada por provável lesão na inserção do trocar. Não ocorreram óbitos durante o procedimento. Conclusão: A técnica se mostrou viável, mas com complicações técnicas relacionadas ao treinamento, tendo o potencial de ser utilizado como acesso venoso alternativo para hemodiálise. Outros estudos podem validar estes achados com o intuito de se utilizar em humanos sem acesso vascular para hemodiálise / Abstract: Purpose: The purpose of this acute experiment is to evaluate in the pigs the feasibility and immediate complications associated with the transpleural cannulation of the azygos vein performed under video-thoracoscopy. Material and Methods: Eight female pigs were submitted to central venous cannulation of the azygos vein guided by vodeo-thoracoscopy of the left side of the thorax. The azygos vein was ligated distally and secured proximally with a double silicone strand loop, intended to be used as bleeding control in case the catheter is withdrawn. Invasive blood pressure with hematimetric and gasometrical data was recorded during the procedure. All animals were sacrificed after the experiment. Results: All animals survived the experiment. There were five successful cannulations. There were two conversions to thoracotomy because of bleeding which, even if minor, hindered the view of the operation field and were successfully converted to thoracomy with direct cannulation of the vein. There was one lung injury caused by a retractor. There was one termination of the procedure because the azygos vein was not found probably because of a lesion during the trocar insertion. Conclusion: In conclusion, the video-thoracoscopic technique was found to be feasible with complications related to technical training and could become an alternative access in patients with unsuitable conventional central venous access. Further investigation could validate these findings / Universidade Estadual de Campi / Ciencias Medicas / Mestre em Cirurgia

Partie I : Objectifs. Ce travail propose une étude anatomique du coeur de porc afin d’élaborer des recommandations pour la réalisation d’une chirurgie cardiaque expérimentale. Matériels et méthodes. 16 porcs ont été étudiés. Le réseau coronaire artériel a été étudié chirurgicalement (n=13) et angiographiquement (n=10). Le réseau veineux coronaire a été analysé par dissections anatomiques (n=13) et injections rétrogrades de bleu de méthylène via le sinus coronaire (n=8). Résultats. Le positionnement intrapéricardique spécifique du coeur de porc, limite l’accès à l’aorte ascendante et à l’oreillette droite et nécessite des précautions particulières pour la réalisation d’une sternotomie et d’une canulation de l’aorte ascendante avec cardioplégie antérograde par la racine de l’aorte. Le réseau coronaire artériel est comparable au réseau humain (réseau droit dominant: 70%). Le sinus coronaire reçoit 4 afférences contre 3 chez l’homme. L’étude de la distribution de surface du réseau veineux nécessite la ligature préalable de la veine azygos gauche et confirme une asymétrie de perfusion au détriment du VD. La paroi antérieure du VD étant drainée par des petites veines cardiaques indépendantes du sinus coronaire. Conclusions. La connaissance des spécificités anatomiques cardiaques du porc a permis d’établir des recommandations pour la réalisation du modèle d’autorétroperfusion myocardique et plus largement de procédures chirurgicales cardiaques expérimentales sécurisées. Partie II : Objectifs. La perfusion rétrograde dans le sinus coronaire est utilisée pour la diffusion d’une solution de cardioplégie. Nous avons développé un modèle porcin d’autorétroperfusion myocardique à coeur battant (SMR) utilisant le réseau veineux coronaire pour assurer l’oxygénation du myocarde ventriculaire gauche. Ce modèle nous a permis d’évaluer les réponses hémodynamiques et cardiaques induites par SMR avant et après occlusion de l’artère IVA. Matériels et Méthodes. Une dérivation entre l’aorte ascendante et le sinus coronaire a été mise en place pour assurer une perfusion rétrograde sélective de la grande veine coronaire en sang oxygéné (SMR). Un groupe Contrôle (n=6) a permis de collecter des données physiologiques de référence et un groupe SMR (n=6) a été spécifiquement dédié à l’évaluation du concept d’autorétroperfusion myocardique après occlusion de l’artère IVA pendant au moins 240 minutes. Le débit cardiaque (CO), la pression maximale intra-VG (Pmax in-LV), le volume éjecté (SV), la fraction d’éjection ventriculaire gauche (FEVG), la durée diastolique (DD), la fréquence cardiaque (HR) et la pression artérielle systémique ont été monitorés en continu durant la période d’autorétroperfusion au moyen d’un cathéter de conductance type Millar® avant et après occlusion de l’IVA. La qualité de la perfusion systémique périphérique a été évaluée par l’analyse de la microcirculation sublinguale. En fin de procédure, les coeurs étaient prélevés pour une analyse histologique. Résultats. L’évaluation échographique de la FEVG était biaisée par la sternotomie alors que celle réalisée par le cathéter de conductance ne l’était pas. Le débit cardiaque après sternotomie a chuté en moyenne de 7.51% (P < 0.05). L’autorétroperfusion avec artère IVA perméable a généré des effets inotropes positifs, caractérisés par une augmentation du CO, du SV, de la Pmax in-LV et de la FEVG (P <0.0001). Après occlusion de l’IVA, l’autorétroperfusion a assuré, durant 240 minutes, une oxygénation myocardique et une compensation hémodynamique garantissant la préservation de la perfusion périphérique. L’analyse histologique a confirmé l’absence d’infarctus myocardique. Conclusions. L’autorétroperfusion myocardique a confirmé des propriétés inotropes positives et protectrices contre l’ischémie ouvrant des perspectives d’applications intéressantes / Part I: Objectives. This work reports an anatomic study of swine heart in order to produce technical recommendations and achieve successful experimental cardiac surgical procedures. Methods. 16 swines were studied. Coronary artery vessels were surgically (n=13) and angiographically (n=10) assessed. Coronary venous vessels were studied by anatomic dissections (n=13) and retrograde injection of methylene blue through the coronary sinus (n=8). Results. Specific pericardial positioning of swine heart dramatically differs from human heart resulting in a limited access to ascending aorta and right atrium, requiring surgical precautions to perform a safe sternotomy and canulation of ascending aorta with an antegrade cardioplegia. Arterial coronary pattern is similar to that of humans (right dominant supply: 70%). Pig coronary sinus receives 4 main branches vs 3 in human sinus. Preliminary ligation of the left azygos vein is required to visualize the surface distribution of methylene blue within the venous vessels, thereby confirming an optimized perfusion of the left ventricle whereas the right ventricle remains poorly perfused. This asymmetry of perfusion results from a specific venous drainage of the right ventricle through small cardiac veins disconnected from coronary sinus. Conclusions. Anatomic knowledge of swine heart validated surgical guidelines for designing the model of self-myocardial retroperfusion and safely performing experimental cardiac surgical procedures. Part II: Background. Retrograde perfusion into the coronary sinus is used to deliver cardioplegia. We developed an in-vivo porcine beating-heart model of self-myocardial retroperfusion (SMR) using the venous route to supply myocardial oxygenation and sought to assess hemodynamic and cardiac responses triggered by SMR before and after a prolonged occlusion of the LAD.Methods. A bypass-line between the ascending aorta and the coronary sinus was made to perform a selective retrograde perfusion of the great cardiac vein with oxygenated blood (SMR). A Control group (n=6) was assigned to collect baseline data, and an SMR group (n=6) was dedicated to undergo SMR with occlusion of LAD for 240 minutes. Cardiac output (CO), maximal pressure in the LV (Pmax in-LV), stroke volume (SV), left ventricular ejection fraction (LVEF), diastolic durations, heart rate, and arterial systemic pressure were evaluated with conductance catheters for the following periods: basal (before SMR), SMR with patent LAD, and SMR with occluded LAD. In order to assess peripheral perfusion, patterns of sublingual microcirculation were analyzed. At the end of the procedures, the hearts were harvested for histology. Results. Echographic LVEF evaluation was affected by sternotomy, but conductance catheter evaluation was not. Following pericardiotomy, CO decreased by 7.51% (P < 0.05). SMR with patent LAD showed inotropic properties with improvements in CO, SV, Pmax in-LV and LVEF (P < 0.0001). Following LAD occlusion, SMR supplied myocardial oxygenation with hemodynamic compensation and preserved the peripheral perfusion. Histology confirmed no signs of infarct. Conclusions. SMR showed capacities to produce inotropic effects and protect against ischemia, opening interesting potential applications