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.

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% to 44% (median: 30%). 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% of the patients (P<0.0001), with a survival rate of 86.9% (mean of 8.9 months of follow-up). CONCLUSION: This technique offers a promising therapeutic alternative for the treatment of patients in refractory heart failure with cardiomyopathy and secondary mitral regurgitation.

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 inserção de uma prótese de Dacron intraluminar, suturada apenas em sua porção proximal, logo após a subclávia esquerda e que transpõe a zona do aneurisma, ficando solta no interior da aorta em sua porção distai (tromba de elefante). A operação é realizada com circulação extracorpórea, hipotermia profunda de 19ºC, com parada circulatória no tempo suficiente para a inserção da prótese e sutura da sua borda proximal. Desde maio de 1988, oito pacientes fizeram parte deste estudo, sendo que seis eram dissecções 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 dissecções de aorta tipo B.

Aneurysms of descending aorta still cause great morbidity and mortality even in modern cardiac surgery days. In this paper, we describe the use of a recente technique which consists in the insertion of an intraluminal Dacron prosthesis, sutured only in its proximal end, just after the left subclavian artery. The prosthesis goes beyoud the aneurysm area and stays free in its distal aortic segment (elephant trunk). The operation is performed with bypass and profound hypothermia at 19ºC with circulatory arrest for just enough time to insert the prosthesis and make the proximal suture. Since May 1988 eight patients underwent this kind of surgery: six cases of acute type B dissection and two cases of saccular aneurysms. The procedure is very simple and fast and the post-operative results obtained make clear that our experience should go on. We recommend this procedure as a tactical alternative, specially for type B dissections.

A substituição valvar por valva aórtica homóloga montada em suporte flexível e preservada pelo glutaraldeído é procedimento original e informações 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 pára implante de próteses biológicas, em virtude de apresentarem idades inferiores a 15 anos, ou, ainda, por calcificação 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 anos e 18 (15,3%) pacientes eram portadores de próteses biológicas calcificadas. Neste grupo de 118 pacientes, em 88 foi realizada a substituição da valva mitral isolada; em 9, substituição mitral e aórtica; em 8, substituição aórtica isolada e, em 2, substituição tricúspide. A mortalidade hospitalar foi de 2,5% (3/118), sendo que o seguimento pós-operatório compreendeu 2614 meses/pacientes, sendo possível obter informações 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 são superiores aos esperados para as outras próteses biológicas, em nossa experiência e na da literatura, e permitindo a recomendação de seu uso, parecendo constituir-se em um avanço, especialmente na substituição valvar de pacientes jovens.

Valvar replacement with a g lutara Id eh yde-pre served, homologous aortic valve in a flexible stent is an original procedure of which we made preliminary reports. We now present up-dated information and follow-up data in a larger cohort of patients. Until now 118 patients have received the prosthesis, most oi them defined as a "high-risk" due either to age less than 15 years old or due to calcification of a previous bioprosthesis. Ages varied from 5 to 66 years (median: 20 y/o); 62 patients (52.5%) were children and 18 (15.3%) had a calcified bioprosthesis. The procedures performed were 88 isolated mitral valve replacement, 9 mitral and aortic replacement, 8 isolated aortic valve and 2 isolated tricuspid substitution. Hospital mortality was 2.5% (3/118); post-operative follow-up consisted of 2614 months/patient with complete and detailed direct follow-up obtained in 91% of survivors, Survival was 94.9%. at 36 months with only 3 deaths in the 115 patients who were discharged from hospital. In our experience and in the literature these results are superior to those with other biological prosthesis: it seems likely that this prosthesis will be highly recommended, specially for children, jf these results are maintained in longer periods.