Mitral valve-in-valve: defining the indication limits by in vitro hydrodynamic tests in a brazilian transcatheter prosthesis

Abstract Introduction: Reoperations in cardiac surgery represent a clinical challenge, particularly because of the higher rate of perioperative morbidity and mortality. Mitral valve reoperation owing to bioprosthesis dysfunction, transcatheter treatment with a prosthesis implantation over the prosthesis has emerged as an alternative, especially for patients with a previous approach. In this study, we analyzed the hydrodynamic behavior of transcatheter prosthesis implantation in conventional mitral bioprostheses through hydrodynamic tests and produced a recommendation for the size of transcatheter valve most adequate for valve-in-valve procedure. Methods: Mitral bioprostheses were attached to a flow duplicator and different combinations of transcatheter prostheses were implanted inside. The equipment simulates the hydrodynamic behavior of the valves submitted in vitro and determines transvalvular pressures and flow parameters. Results: All tests could be performed. Better hydrodynamic performance occurred for transcatheter prostheses 1 mm smaller than bioprostheses, except for the 27-mm bioprostheses. Effective valve areas (cm²) and transvalvular gradients (mmHg) were, respectively: Bioprosthesis × Inovare: 27 × 28 mm: 1.65 and 5.95/29 × 28 mm and 31 × 30 mm: 2.15 and 3.6. Conclusion: The mitral valve-in-valve implantation proved to be feasible in vitro. The use of 27-mm bioprostheses should be judicious, with preference for a 26-mm transcatheter valve. In the 29 and 31-mm bioprostheses, the implantation was very satisfactory, with good effective valve areas and transvalvular gradients, with preference for smaller transcatheter valves.

Nova abordagem cirúrgica para o tratamento de pacientes em insuficiência cardíaca refratária com miocardiopatia dilatada e insuficiência mitral secundária / A new surgical appoach for treating dilated cardiomyopathy with mitral regurgitation

OBJECTIVE : To evaluate the early outcome of mitral valve prostheses implantation and left ventricular remodeling in 23 patients with end-stage cardiomyopathy and secondary mitral regurgitation (NYHA class III and IV). METHODS : Mitral valvular prosthesis implantation with preservation of papillary muscles and chordae tendinae, and plasty of anteriun cuspid for remodeling of the left ventricle. RESULTS : The surgery was performed in 23 patients, preoperative ejection fraction (echocardiography) varied from 13 per cent to 44 per cent (median: 30 per cent). In 13 patients associated procedures were performed: myocardial revascularization (9), left ventricle plicature repair (3) and aortic prosthese implantation (1). Early deaths (2) occurred on the 4th PO day (cardiogenic shock) and on the 20th PO day (upper gastrointestinal bleeding), and a late death in the second month PO (ventricular arrhythmia). Improvement occurred in NYHA class in 82.6 per cent of the patients (P<0.0001), with a survival rate of 86.9 percent (mean of 8.9 months of follow-up). CONCLUSION : This technique offers a promising therapeutic alternative for the treatment of patients in refractory heartfailure with cardiomyopathy and secondary mitral regurgitation.

Estudo comparativo do ecocardiograma dopller transtorácico, tomografia computadorizada e aortografia no diagnóstico de dissecçäo da aorta torácica / Comparative Evaluation of Transthoracic Doppler Echocardiogram, Computed Tomography and Aortography in the Diagnosis of Thoracic Aortic Dissection.

PURPOSE--Comparative and prospective evaluation of three methods (transthoracic echo-Doppler (TTE), computerized tomography (CT) and aortography (AORT) utilized for aortic dissection diagnosis. METHODS--The 39 patients with confirmed aortic dissection (surgery or autopsy) underwent, within a few hours of each other, all three methods scrutinized. There were 19 cases of type A and 20 of type B dissection. RESULTS--In type A dissection the methods were equivalent (TTE = 73.7//, CT = 84.2//, AORT = 73.7//p = NS) but for type B, TTE was significantly inferior to the other two methods (TTE = 60//, TC 90//, AORT = 80//, p < 0.05 for TTE, for TC and AORT p = NS). In three occasions, even though all three methods were performed, the diagnosis was not obtained. CONCLUSION--The methods which were evaluated make the diagnosis in the majority of cases. In type A all methods are similar, however, in type B, TC and AORT are superior to TTE. Even performing all three methods in each patient, in three instances the diagnosis was not made

Tratamento dos aneurismas da aorta descendente por endoprótese (tromba de elefante) / Treatment of descending aorta aneurysms with endoprosthesis (elephant trunk)

Os aneurismas da aorta descendente ainda causam grande mortalidade e morbidade, apesar dos avanços da cirurgia cardiovascular moderna. Neste trabalho utilizamos, originalmente em nosso meio, uma técnica recente que consiste na inserçao de uma prótese de Dacron intraluminar, suturada apenas em sua porçao proximal, logo após a subclávia esquerda e que transpoe a zona do aneurisma, ficando solta no interior da aorta em sua porçao distal (tromba de elefante). A operaçao é realizada com circulaçao extracorpórea, hipotermia profunda de l9 graus Celsius, com parada circulatória no tempo suficiente para a inserçao da prótese e sutura da sua borda proximal. Desde maio de 1988, oito pacientes fizeram parte deste estudo, sendo que seis eram dissecçoes da aorta tipo B e dois casos, aneurismas verdadeiros. A simplicidade e rapidez do procedimento, assim como os resultados pós-operatórios obtidos nos animam a prosseguir e recomendar este tipo de alternativa tática, especialmente nas dissecçoes de aorta tipo B.

Substituiçäo valvar por valva aórtica homóloga montada em suporte e preservada pelo glutaraldeído: estudo multicêntrico / Valvar replacement with a glutaraldehyde preserved stentmounted homologous aortic valve: a multicenter study

A substituiçäo valvar aórtica homóloga montada em suporte flexível e preservada pelo glutaraldeído é procedimento original e informaçöes preliminares já foram relatadas anteriormente. O objetivo do atual estudo multicêntrico é apresentar os resultados tardios em grupo maior de pacientes, nos quais uma ou mais valvas cardíacas foram substituídas por valva aórtica homóloga. Os autores analisam os resultados em 118 pacientes selecionados, considerados de alto risco para implante de próteses biológicas. Em virtude de apresentarem idades inferiores a 15 anos, ou, ainda, por calcificaçäo de próteses biológicas implantadas anteriormente. As idades variaram de 5 a 66 anos (mediana 20 anos), sendo que 62 (52,5%) tinham idade igual ou inferior a 15 e 18 (15,3%) pacientes eram portadores de próteses biológicas calfcificadas. Neste grupo de 118 pacientes, em 88 foi realizada a substituiçäo da valva mitral isolada; em 9, substituiçäo mitral e aórtica; em 8, substituiçäo aórtica isolada e, em 2, substituiçäo tricúspide. A mortalidade hospitalar foi de 2,5% (3/118), sendo que o seguimento pós-operatório compreendeu 2614 meses/pacientes, sendo possível obter informaçöes atualizadas em 91% dos sobreviventes. A curva atuarial de sobrevida, ao final de 36 meses, foi de 94,9%, tendo ocorrido apenas 3 óbitos tardios, nos 115 pacientes que receberam alta hospitalar. Estes resultados säo superiores aos esperados aos para as outras próteses biólógicas, em nossa experiência e na da literatura, e permitindo a recomendaçäo de seu uso, parecendo constituir-se em um avanço, especialmente na substituiçäo valvar de pacientes jovens