Estudo experimental do implante transcateter de prótese valvulada autoexpansível na via de saída do ventrículo direito em porcos
Data
2014
Autores
Guilhen, José Cícero Stocco 
Orientadores
Buffolo, Enio
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: A disfunção da via de saída do ventrículo direito (VSVD) e uma alteração frequentemente encontrada no seguimento de pacientes submetidos a correção de cardiopatias congênitas complexas, sobretudo nas doenças que necessitam de ampliação da via de saída do ventrículo direito para sua correção. A insuficiência ou estenose pulmonar residual pode acarretar falência cardíaca direita com deterioração clínica. Esses pacientes necessitam de múltiplas intervenções ao longo de suas vidas. Objetivo: O presente estudo tem por objetivo o desenvolvimento de uma prótese valvulada para implante na via de saída do ventrículo direito com técnica menos invasiva, sem a necessidade de circulação extracorpórea. Método: A prótese consiste em um anel metálico auto expansível, construído com nitinol, revestido de poliéster, onde três cúspides de pericárdio bovino foram montadas. Doze porcos foram utilizados para a realização dos implantes. Foi realizado controle ecocardiográfico para avaliar o gradiente transvalvar e a presença de refluxo na prótese. Resultados: O implante foi realizado em todos os 12 animais. Um animal apresentou refluxo de grau moderado, e outros quatro, refluxo de grau leve. Logo após o implante houve aumento dos gradientes que variaram de 7 a 45 mmHg. Em apenas quatro dos 12 animais os gradientes se mantiveram acima de 20 mmHg. Em seis animais ocorreu formação de trombo na prótese, sendo esta a complicação mais frequente. Conclusão: O implante transventricular de válvula pulmonar através de cateter pode ser realizado em porcos demonstrando funcionamento hemodinâmico satisfatório com gradientes baixos. A trombose mostrou-se uma complicação frequente no estudo.
Introduction: Right ventricular outflow tract dysfunction is a condition often found during follow-up of patients undergoing repair of complex congenital heart disease especially in those that require enlargement of right ventricle outflow tract. The residual pulmonary insufficiency or stenosis can lead to right heart failure with clinical deterioration. These children often require multiple interventions throughout their lives. Objective: To develop a less invasive technique for implantation of a self-expandable valved prosthesis in pulmonary position through the right ventricle without cardiopulmonary bypass. Methods: The valved prosthesis consists of an auto expanding metal stent built with nitinol, surrounded with polyester, where three leaflets of bovine pericardium were mounted to create a valve. Twelve pigs were used to perform the implants. Echocardiographic control was performed to measure the gradient and competency of the prosthesis. Results: The implantation was performed in all 12 animals. One animal presents with moderate periprosthetic leak and other four developed mild regurgitation during follow up. Transvalvular gradients after implantation ranged from 7 to 45 mmHg. In only four of the twelve animals the gradients were above 20 mmHg. Thrombus formation occurred in the prosthesis of six animals, and this was the most frequent complication. Conclusion: Transcatheter implantation of selfexpandable valve prosthesis is possible as demonstrated, with good hemodynamic parameters. Thrombus formation was shown to be a frequent complication.
Introduction: Right ventricular outflow tract dysfunction is a condition often found during follow-up of patients undergoing repair of complex congenital heart disease especially in those that require enlargement of right ventricle outflow tract. The residual pulmonary insufficiency or stenosis can lead to right heart failure with clinical deterioration. These children often require multiple interventions throughout their lives. Objective: To develop a less invasive technique for implantation of a self-expandable valved prosthesis in pulmonary position through the right ventricle without cardiopulmonary bypass. Methods: The valved prosthesis consists of an auto expanding metal stent built with nitinol, surrounded with polyester, where three leaflets of bovine pericardium were mounted to create a valve. Twelve pigs were used to perform the implants. Echocardiographic control was performed to measure the gradient and competency of the prosthesis. Results: The implantation was performed in all 12 animals. One animal presents with moderate periprosthetic leak and other four developed mild regurgitation during follow up. Transvalvular gradients after implantation ranged from 7 to 45 mmHg. In only four of the twelve animals the gradients were above 20 mmHg. Thrombus formation occurred in the prosthesis of six animals, and this was the most frequent complication. Conclusion: Transcatheter implantation of selfexpandable valve prosthesis is possible as demonstrated, with good hemodynamic parameters. Thrombus formation was shown to be a frequent complication.
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Citação
GUILHEN José Cícero Stocco. Estudo experimental do implante transcateter de prótese valvulada autoexpansível na via de saída do ventrículo direito em porcos. 2014. 120 f. Tese (Doutorado em Ciências) – Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 2014.