ABSTRACT

The preliminary postoperative results in 16 patients submitted to valvular replacement utilising bovine pericardial valvular bioprostheses, without resection of their natural cusps, are presented. These patients were operated on sequentially from March to September 1989. The incompetent cusps were sutured to the mitral annulus with U stitches placed at their free edges. Pre and postoperative evaluation of the following parameters were obtained: left atrial diameters, left ventricular diameters, ejection fraction and mitral transvalvular gradients (peak and mean). Statistical evaluation utilising the Student's T test was performed. Preoperative mean value of the left ventricular diameter was 67.31 mm, decreasing to 60.50 mm in the postoperative evaluation. Critical value of T was 2.131, the value observed for the left ventricle variation being 3.18. The left atrial diameter varied from 60.25 mm to 49.31 mm (T equal to 6.72). Preoperative ejection fraction mean value was 0.72 and in the postoperative was 0.65 (T = 2.68). Mean transvalvular gradients varied from 23.7 mm (peak) and 12.5 mm (mean) to 9.10 and 5.125 respectively. These residual values are acceptable according to the current literature and the experience of our Institution. There were no complications or deaths in the present series. In no patient gradients in the left ventricular out flow tract suggesting obstruction by the anterior cusp were observed. The authors consider it an efficient technique, easily and rapidly performed, without danger of atrioventricular desinsertions and without significant gradients. Ventricular performance is enhanced and the left atrial and left ventricular diameters decrease considerably.

RESUMO

O objetivo deste trabalho é apresentar os resultados pós-operatórios preliminares de 16 pacientes submetidos a implante de bioprótese valvular de pericárdio bovino com preservação de suas valvas naturais, operados seqüencialmente no período de março a setembro de 1989. As cúspides insuficientes foram pregueadas no anel mitral com pontos em U passados nas bordas livres e no anel mitral, sem quaisquer ressecções. Foram feitos estudos comparativos no pré e no pós-operatório das seguintes grandezas: diâmetro do átrio esquerdo, diâmetro do ventrículo esquerdo (VE), fração de ejeção e gradiente transvalvares mitrais (pico e médio). A avaliação estatística foi feita através do teste T de Student. O valor médio do diâmetro do VE no pré-operatório era de 67,31 mm, caindo para 60,50 mm no pós-operatório. O valor crítico de T foi 2,131, sendo o valor observado para a variação do diâmetro de VE igual a 3,18. O diâmetro de átrio esquerdo (AE) variou de 60,25 mm para 49,31 mm com T igual a 6,72. O valor médio da fração de ejeção no pré-operatório foi de 0,72, variando para 0,65 com T igual a 2,68. Os gradientes (valores médios) transvalvares variaram de 23,7 mm de Hg de pico e 12,5 de média, respectivamente, para 9,10 e 5,125. Estes valores residuais são perfeitamente aceitáveis de acordo com a literatura e a própria experiência do Serviço. Não houve complicações ou óbitos na série. Em nenhum paciente ocorreu gradiente na via de saída de VE que pudesse sugerir obstrução pela cúspide anterior. Os autores concluem pela eficácia da técnica a qual é de fácil e rápida execução, afasta desinserções atrioventrículares, não gera gradientes, favorece ótimo desempenho ventricular com rápida e acentuada regressão dos diâmetros de AE e VE.

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