Estudo experimental com heteroenxertos valvares descelularizados: a protese do futuro



Document title: Estudo experimental com heteroenxertos valvares descelularizados: a protese do futuro
Journal: Brazilian journal of cardiovascular surgery
Database: PERIÓDICA
System number: 000290447
ISSN: 1678-9741
Authors: 1






Institutions: 1Santa Casa de Misericordia, Servico de Cirurgia Cardiaca, Curitiba, Parana. Brasil
Year:
Season: Ene-Mar
Volumen: 19
Number: 1
Pages: 74-82
Country: Brasil
Language: Portugués
Document type: Artículo
Approach: Experimental, analítico
English abstract OBJECTIVE: To make a comparative evaluation of the behaviour of cryopreserved homografts and deccelularized porcine heterografts implanted in the right ventricular outflow tract of juvenile sheep as well as to report the initial clinical experience with deccelularized pulmonary homografts in patients submitted to the Ross procedure. METHOD: In group A, four cryopreserved homografts were implanted and group B consisted of four heterografts deccelularized with deoxicolic acid. In each group, two animals were sacrificed at 90 days and the other two at 150 days. The explants were evaluated macroscopically, and radiologically, besides histological examination with HE, Gomori and Sirius Red staining,. We also report our initial clinical experience with deccelularized pulmonary homografts in four patients submitted to the Ross procedure. RESULTS: A ll the animals survived. By echo all the implanted valves had normal function. Although the cusps had normal appearance in both groups, calcium content was higher in the cryopreserved valves and radiologically there were traces of calcification in the cryopreserved valves but none in the deccelularized valves. Cryopreserved homografts lost their cellularity while deccelularized heterografts were progressivelly repopulated by fibroblasts and were partially reendothelized. Four patients submitted to a Ross operation with deccelularized homografts had a good clinical outcome with normal function in their right sided homografts. CONCLUSIONS: Deccelularized heterografts were progressivelly repopulated by autologous cells and exhibted minimal tendency to calcification in this model. These results suggest that deccelularized heterografts may have some regenerative capacity and thus potencially greater durability than conventional cryopreserved homografts
Portuguese abstract OBJETIVO: Avaliar, comparativamente, o comportamento de homoenxertos valvares criopreservados e de heteroenxertos descelularizados implantados na via de saída do ventrículo direito de carneiros jovens, assim como relatar a experiência clínica inicial com homoenxertos descelularizados em pacientes submetidos à operação de Ross. MÉTODO: No grupo A, foram implantados quatro homoenxertos pulmonares criopreservados e no Grupo B, quatro heteroenxertos porcinos valvares descelularizados com ácido deoxicólico. Em cada grupo, dois animais foram sacrificados no 3º mês e dois no 5º mês de pós-operatório. As peças foram avaliadas macroscopicamente e por radiografias, além de exame microscópico com colorações HE, Tricrômico de Mallory e Sirius Red. A experiência clínica com quatro pacientes submetidos à operação de Ross com emprego de homoenxertos valvares descelularizados é relatada. RESULTADOS: Todos os animais sobreviveram. Os ecocardiogramas demonstraram boa função valvar nos dois grupos. Embora as cúspides valvares em ambos os grupos tivessem aspecto macroscópico normal, a mensuração de cálcio e o estudo radiológico demonstraram início de calcificação focal nos homoenxertos criopreservados, mas não nos heteroenxertos descelularizados. Esses achados foram confirmados por exames microscópicos. Os homoenxertos criopreservados demonstraram perda de sua celularidade, enquanto que os heteroenxertos descelularizados demonstraram repopulação progressiva da matriz colágena com fibroblastos, assim como reendotelização. Os quatro pacientes operados t
Disciplines: Medicina
Keyword: Cirugía,
Sistema cardiovascular,
Homoinjertos,
Válvulas cardiacas,
Cerdos,
Ingeniería de tejidos
Keyword: Medicine,
Cardiovascular system,
Surgery,
Homografts,
Heart valves,
Swine,
Tissue engineering
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