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    Análise Do Comportamento Hidrodinâmico In Vitro Dos Implantes De Próteses Valvares Transcateter Dentro De Biopróteses Aórticas Convencionais: Uma Nova Alternativa À Reoperações
    (Universidade Federal de São Paulo (UNIFESP), 2017-12-21) Cardoso, Caio Cesar [UNIFESP]; Fonseca, Jose Honorio De Almeida Palma Da [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    OBJECTIVE: Hydrodynamic evaluation of the transcatheter valve implantation in aortic bioprosthesis (valve-in-valve) and in sets of bioprosthesis with a transcatheter valve previously implanted (valve-in-valve-in-valve or sequential valve-in-valve), in order to guide therapeutic limits and the optimal transcatheter valve size. METHODS: With the Pulse Duplicator, and accordingly to FDA and ISO 5840 determinations for cardiac output (5L/min), mean arterial blood preesure (100mmHg) and cardiac frequency variation (70-120), the hydrodynamics tests were procedded to measure efective orificial area (EOA-cm²) and transvalvar gradient (ΔP-mmHg) for each set of valve-in-valve and valve-in-valve-in-valve. The valve-in-valve tests: for each bioprosthesis (Braile Biomédica), between 19mm and 25mm, a transcatheter valve (Braile Inovare, with nominal sizes between 20 and 26mm), either 1mm larger or 1mm smaller, was implanted. The valve-in-valve-in-valve tests: for each optimal set of valve-in-valve (determined in the valve-in-valve tests), a transcatheter valve 2mm smaller than the previous was implanted. Each set described of valve-in-valve or valve-in-valve-in-valve was replicated ten times, and the tests in the Pulse Duplicator were performed for each set three times. RESULTS: The set aortic bioprosthesis 19mm and transcatheter valve 20mm, the EOA was 0,5 and the ΔP was 43,7. Moreover, the sets 21-20 and 21-22 resulted in EOA 0,8 and 0,73, and ΔP 19,4 and 23,4. For the sets 23-22 and 23-24, the tests showed EOA 1,06 and 0,8, and ΔP 12,5 and 19,5. And finally, for the sets 25-24 and 25-26, the EOA was 1,085 and 1,0, and the ΔP was 11,76 and 13,56. The valve-in-valve-in-valve tests has shown that the implantation of a transcatheter valve 22mm in a valve-in-valve set of a 25mm bioprosthesis with the 24mm valve transcathter resulted in EOA 0,99 and ΔP 13,59; when for this set was proceeded the implantation of a third transcatheter valve (20mm), was observed an EOA 10 0,84 and a ΔP 15,31. In a valve-in-valve set with a 23mm bioprosthesis and a 22mm transcatheter valve, the EOA was 0,86 and the ΔP was 15,62 when a 20mm transcatheter valve was implanted. CONCLUSION: The aortic valve-in-valve is fasible, with better hydrodynamic results when the transcatheter valve has the nominal size 1mm smaller than the bioprosthesis; this fact can be explained considering the appropriate oversizing between the bioprosthesis true internal diameter and the transcatheter external diameter (between 10 and 20%). The valve-in-valve in 21mm bioprosthesis should be individualized, and in 19mm prohibited. The transcatheter valve-in-valve-in-valve is feasible as well, with great performance with a sequential implantation of a smaller transcatheter valve up to the 22mm, the 20mm should be cautiously implanted; the oversizing between the immediate smaller transcatheter valve was between 4 and 5%.