Bayard Gontijo Filho

Retrospective clinical analysis of stented vs. stentless porcine aortic bioprostheses

OBJECTIVE The study was designed to compare hemodynamic performance, structural failure and survival of patients undergoing aortic valve replacement (AVR) with a composite aortic stented or stentless porcine bioprosthesis. METHODS From January 1990 to June 1999, the clinical data of 725 patients undergoing AVR with stented porcine aortic bioprosthesis were reviewed. We defined two groups of patients with similar clinical characteristics: 202 patients receiving aortic stented and 205 patients stentless valves. The two patients groups were similar in age, sex, valve lesion, valve size, preoperative New York Heart Association (NYHA) class status and follow-up. RESULTS The number of patients available for follow-up, excluding hospital and late mortality, reoperations and patients lost to follow-up, was 157 for the stented and 175 for the stentless group. There was a higher incidence of rheumatic heart disease in the stented (59%) vs. stentless group (44%), (P=0.003). Fewer patients had prior aortic bioprosthetic dysfunction in the stented (7.6%) compared to the stentless group (25%) (P<0.001). The mean intensive care unit stay, hospital mortality and late mortality were similar (P, NS). The total complication rate was higher in the stented (12%) than the stentless (3.4%)(P=0.005). Valve related death was higher in the stented (2.5%) than the stentless (0%) (P=0. 049). Postoperatively, the aortic effective orifice area (AEOA) was larger (P<0.001) and the transvalvular peak and mean gradients were lower in the stentless group (P<0.001). The leaflet tissue degeneration analysis was 8.0% in patients at risk for stented and 0. 6% for stentless (P=0.001). Actuarial analysis disclosed no statistical difference in patient survival between groups (P=0.18). Reoperations were less frequent in the stentless group (P=0.010). CONCLUSIONS Hemodynamic benefits in the stentless group were evident and expressed by larger AEOA, lower gradients, better left ventricular remodeling with significant decrease of the left ventricular mass. Lower complication rates, lower reoperation rates, less leaflet tissue degeneration, and lower valve related mortality rates were seen in the stentless group. A controlled clinical comparison trial with longer follow-up will be required to confirm these clinical and hemodynamic benefits.

Modified Norwood procedure for hypoplastic left heart syndrome

OBJETIVO: Apresentar os resultados do tratamento da sindrome de hipoplasia do coracao esquerdo (SHCE) com tecnica de Norwood modificada, na qual somente sao usados tecidos autologos para a reconstrucao do arco aortico. METODO: De janeiro a dezembro de 2002, cinco recem-nascidos com idade variando de dois a nove dias (media 5,0 dias) foram submetidos a operacao de Norwood modificada. O diâmetro da aorta ascendente variou de 5 a 8 mm (media 6,2 mm). Foi empregada tecnica na qual o arco aortico e seus ramos foram amplamente dissecados, permitindo a reconstrucao de um novo arco aortico tendo a arteria pulmonar como via de saida, e com a utilizacao exclusiva de tecidos do proprio paciente. Anastomose sistemico-pulmonar com politetrafluoretileno expandido de 3,0 mm foi utilizada em tres pacientes e de 3,5 mm em dois pacientes. Todos foram operados com parada cardiocirculatoria total. RESULTADOS: O tempo de parada cardiocirculatoria variou de 41 a 60 minutos (media 52,8 minutos). Todas as criancas sobreviveram ao ato operatorio e foram encaminhadas para a unidade de terapia intensiva com o esterno aberto. Ocorreu um obito no 9: dia de pos-operatorio por sepse, o que resultou numa taxa de sobrevivencia imediata de 80%. Ocorreu um obito tardio por pneumonia de aspiracao aos dois meses. Uma crianca foi submetida ao segundo estagio da operacao (cavo pulmonar) e encontra-se bem. Duas criancas estao em acompanhamento aguardando o proximo estagio. Em nenhuma delas existem evidencias de obstrucao do novo arco aortico. CONCLUSAO: A tecnica de Norwood modificada mostrou-se eficaz e com risco cirurgico aceitavel para o tratamento da SHCE, sem evidencias de obstrucao do arco aortico reconstruido.

Estratégia cirúrgica na transposição das grandes artérias associada à obstrução do arco aórtico

Objective: Our results on the transposition of the great arteries with aortic arch obstruction were analyzed to establish our present protocol.

Reconstrução da artéria pulmonar na operação de Jatene

INTRODUCTION: We describe our experience with Jatenes operation in the surgical treatment of transposition of great arteries (TGA) where pulmonary artery reconstruction was performed with two autologous pericardial patches in order to spare the maximum amount of native aortic tissue. MATERIAL AND METHODS: There were 52 children (38 simple TGA, 14 TGA + VSD) and their age ranged from 3 days to 17 months. Body weight ranged from 2.400 to 7.400 kg (m=3.377 kg). All patients were operated under moderate hypothermia with a single infusion of blood cardioplegia. Average extracorporeal circulation time was 110.6 min and average aortic cross-clamping time was 72.5 min. RESULTS: There were 3 (5.8%) early deaths caused by pulmonary infection in 2 of them and by obstruction of the endotracheal tube in 1. There were 2 late deaths; one in a reoperation of severe coronary ostial stenosis (6 months p.o.) and another owing to pneumonia (1 year p.o.). Late echocardiography was performed in 20 children who were operated in the neonatal period and had a minimum of 5 months follow-up (m=12.7). Supravalvular pulmonary stenosis was found in only 1 (5%) patient and results were consistent with an uniform pulmonary artery development. CONCLUSION: Reconstruction of the pulmonary artery in Jatenes operation for TGA should be carried out with maximal preservation of the native aortic tissue.

Cirurgia de Glenn bidirecional: importância da manutenção de fluxo "pulsátil" na artéria pulmonar

In order to evaluate the effects of pulsatile flow in the pulmonary artery of patients undergoing bidirectional cavopulmonary shunts (BCS), we reviewed the data of 36 patients operated upon from October 1990 to July 1994. Age at operation ranged from 11 months to 14 years (mean 4.4 ± 3.4 years) and diagnoses were as follows: tricuspid atresia (18), single ventricle (16), mitral atresia (1) and pulmonary atresia with intact ventricular septum (1). A total of 19 (52.8%) patients had a prior palliative operation done. Cardiopulmonary bypass was used in every case, with mild hypothermia in 11 cases and profound hypothermia and circulatory arrest in the remaining. The surgical technique was an anastomosis between the superior vena cava and the ipsilateral pulmonary artery in an end-to-side fashion. The main pulmonary artery was ligated only if the mean pressure taken at the site of the anastomosis was higher than 15 mmHg but in 2 recent cases with a very high mean pulmonary pressure, the main pulmonary artery was banded, adjusting the pressure to the desirable levels. The overall hospital survival was 91.7% (33 patients). One patient required a systemic to pulmonary shunt due to persistent low arterial oxygen saturation, 7 days after the BCS. Twenty-eight patients were followed for a mean of 1.8 ± 1.2 years (3 months to 4.1 years) and were divided in 2 groups: A-18 patients without pulsatile flow in the pulmonary artery, and B-10 patients with pulsatile flow. In Group B, the mean arterial saturation has ranged from 80% to 90% (mean 86 ± 3.8%) and is significantly higher than in Group A (68 to 85%, mean, 77.6 ± 5.5) (p<0.001). Two patients of Group A are in NYHA functional class III, whereas all patients of Group B are in class I or II (p=0.05). There was one late death and one patient required a subsequent Fontan procedure, both of Group A. Thus, the presence of pulsatile flow in the pulmonary artery improved the arterial oxigen saturation and exercise tolerance in patients submitted to a cavopulmonary shunt, without adverse effects on pulmonary circulation.

Estudo multicêntrico dos resultados das trocas valvares com o uso da bioprótese Biocor no Estado de Minas Gerais

No periodo de marco de 1981 a marco de 1988, foram implantadas 2324 bioproteses, em 2016 pacientes, em 5 Centros do Estado de Minas Gerais. Este estudo inclui somente a analise dos pacientes submetidos a troca valvar aortica (n = 603) e mitral ( n = 1110), isoladamente. Neste grupo (n = 1713), a mortalidade hospitalar foi de 104 pacientes (6,1%). Dos 1609 pacientes que receberam alta do hospital, conseguimos o seguimento de 1101 pacientes (64,3). Esta analise corresponde a um periodo de 1 a 84 meses, com media de 48 meses e com um seguimento cumulativo de: aorticas (n= 385) = 1230 pacientes/ano; mitrais (n = 716) = 3018 pacientes/ano. Foram registradas 102 complicacoes tardias em 716 pacientes mitrais (14,24%) e 51 complicacoes no grupo aortico (13,2%). Com relacao a faixa etaria, encontramos 220 pacientes menores de 20 anos (mitrais = 176/aorticos = 44) e, neste subgrupo, as disfuncoes valvares incidiram em 43% dos pacientes mitrais e em 29% dos pacientes aorticos. A endocardite protetica foi mais encontrada nos aorticos (45%) do que nos mitrais (29,7%). Dos 1101 pacientes, 62 foram reoperados, com mortalidade hospitalar de 12,6%. A reoperacao por disfuncao valvar foi mais frequente no grupo mitral com idade inferior a 20 anos. A curva atuarial livre de mortalidade relacionada a bioprotese foi de 97,1% (32/1101 pacientes). No grupo aortico, 96,9% estiveram livres de disfuncao valvar ao final de 7 anos, enquanto que, no grupo mitral, este indice foi de 95,2%. Nos pacientes menores de 20 anos do grupo mitral, encontramos o maior indice de falencia valvar (85,3% livre apos 7 anos). Ao final deste estudo, a maior parte destes pacientes encontrava-se em classe funcional I e II. Embora a incidencia de reoperacao seja expressiva, esta e aceitavel, tendo em vista que as bioproteses oferecem uma alternativa mais segura do que as proteses mecânicas, durante este mesmo periodo do seguimento. A analise destes resultados sugere a continuacao de pesquisas que tornem possivel a fabricacao de um substituto valvar ideal. Todavia, estes resultados comparam-se, de modo favoravel, a resultados com bioproteses semelhantes da literatura mundial.

Síndrome de Wolff-Parkinson-White associada a comunicação interatrial tipo seio venoso

The Wolff-Parkinson-White syndrome (WPW) and sinus venosus atrial septal defect (ASD) association is very rare and not yet reported in the literature. It is the main basis for this case report.

Tratamento cirúrgico dos aneurismas e dissecções do arco aórtico

From Jan/1990 to Mar/1999 we performed 354 operations on the thoracic aorta in our hospital. Among these, 47 procedures involved the aortic arch; 31 patients were male (66.0%) and ages ranged from 26-74 years (mean = 54.9 ± 10.9). Aortic dissection was present in 33 patients (70.2%) and fusiform or sacular aneurysms in 14 (29.8%). Previous cardiac procedures had been performed in 11 patients (23.4%), rupture with cardiac tamponade was present in 4 patients. Median sternotomy was used in 42 cases and bilateral thoracotomy in 5. Deep hypothermia with circulatory arrest was used in 97.8% of cases with the arrest period ranging from 15 to 60 minutes (m = 30.6 ± 12.6). Anterior hemiarch reconstruction was used in 19 patients (40.4%), posterior hemiarch in 5 (10.6%), total arch replacement in 18 (38.3%) aortoplasty in 4 (8.5%) and extra-anatomic bypass with exclusion in 1 (2.1%). The main associated procedures were: myocardial revascularization (9), ascending aorta replacement by a valved conduit (15), elephant trunk (5) and aortic valve replacement (3). Hospital mortality was 12,3% (6 patients) and respiratory insufficiency was the most common non-fatal complication (7 cases). Determinant factors for hospital mortality showed a statistical tendency for age over 60 years (p = 0.17) and for acute aortic dissection (p = 0.07). Late follow-up was achieved in 95.12% of the hospital survivors. There were 3 late deaths (1 cerebro-vascular accident, 2 reoperations). The 9 year survival rate is 80.85%.

Substituição da aorta ascendente e arco aórtico por enxerto de pericárdio bovino: resultados a médio prazo

Bovine pericardial (P.B.) grafts are in clinical use at Biocor Institute since 1989 for replacement or repair of the ascending aorta (AsAo) and the initial segment of the aortic arch (AoAr); the main advantages of B.F. grafts that justified its clinical application are: easiness to handle, fully hemostatic and low cost. This study was conducted to analyse the fate of the heterograft after a minimum of 2 years of implantation. From February 1989 to Frebruary 1994, 84 patients had a B.P. graft implanted in the AsAo or AoAr. The total hospital mortality was 18%. Thirty-one patients who had two years of follow-up were selected for analysis of the B.P. graft (mean follow-up = 40.9 months). They underwent either an echocardiographic examination or an aortographic study (n=15) in order to determine the presence of dilatation, calcification, thrombus and pseudoaneurysm. In all patients the graft was functioning perfectly and no abnormalities were recorded. The current follow-up is short and complications such as calcification and pseudoaneurysm may still develop, therefore a longer time is required. The present study has shown superior handling and hemostatic properties over the classical Dacron grafts and no adverse behavior was noted during this 4 years of study.

Transplante de valva mitral heteróloga: Nova alternativa cirúrgica: estudo clínico inicial

Mitral valve replacement has been performed for the last 30 years using an aortic designed valve, to fulfil specific requirements of the left ventricle. The clinical results obtained by such devices have been generally favorable, although specific restrictions are obvious because of their design. The knowledge and experience acquired by Biocor Laboratories in the last two decades, in production of biological heart valve substitutes, contributed positively to the research, development and manufacture of the heterologous mitral valve substitute. This stentless heterologous mitral valve was implanted in 38 patients, without hospital mortality. Their mean age was 29 years. Female gender predominated (69%). The most common mitral dysfunction was the double mitral valve lesion (53%). Eighteen (47%) patients were in functional class III and 20 (53%) in class IV of the NYHA. There was one valve related complication (our first patient), due to disproportion of patients, large annulus and the incorrectly size chosen. This complication led us to the strict adherence of our protocol, which is based upon animal experimentation. The satisfactory operatory and clinical results, throughout this 12 months of follow-up, confirm that the stentless heterologous mitral valve is the natural mitral substitute, when considering mitral valve replacement. This first natural mitral valve substitute, tanned with a non-aldehyde tissue treatment, proved to avoid calcification and to produce no foreign reaction, hence it may be the best choice in order to obtain better quality of life and the desired valve durability. Using both, the natural design mitral valve and the non-aldehyde treatment, the last 6 patients of this series received this devicxe and is certainly hoped that, due to the more natural model and the non-calcificant and inhert tissue, patients own cells will be responsible to greatly delay tissue degeneration, providing longterm durability.