Evoluçäo imediata e tardia das substituiçöes valvares em crianças menores de 12 anos de idade / Immediate and long term evolution of valve replacement in children less than 12 years old

ABSTRACT

OBJECTIVE - The aim of this work was the follow-up and evaluation of valve replacement in children under 12 years of age. METHODS - Forty-four children less than 12 years old were underwent valve replacement at INCOR-HCFMUSP between January 1986 and December 1992. Forty (91 per cent) were rheumatic, 39 (88.7 per cent) were in functional classes II or IV, 19 (43.2 per cent) were operated upon on an emergency basis, and 6 (13.6 per cent) had atrial fibrillation. Biological prostheses (BP) were employed in 26 patients (59.1 per cent), and mechanical prostheses (MP) in 18 (40.9 per cent). Mitral valves were replaced in 30 (68.7 per cent), aortic valves in 8 (18.2 per cent), a tricuspid valve in 1 (2.3 per cent), and double (aortic and mitral) valves in 5 (11.4) of the patients. RESULTS - Hospital mortality was of 4.5 per cent (2 cases). The mean follow-up period was 5.8 years. Re-operations occurred in 63.3 per cent of the patients with BP and in 12.5 per cent of those with MP (p=0.002). Infectious endocarditis was present in 26.3 per cent of the BP, but in none of the cases of MP (p=0.049). Thrombosis occurred in 2 (12.5 per cent) and hemorrhage in one (6.5 per cent) of the patients with a MP. Delayed mortality occurred in 5 (11.9 per cent) of the patients over a mean period of 2.6 years; four had had BP and one had a MP (NS). Actuarial survival and re-operation-free curves after 10 years were respectively, 82.5 + or - 7.7 (SD)per cent and 20.6 + or - 15.9 per cent. CONCLUSION - Patients with MP required fewer re-operation, had less infectious endocarditis and lower late mortality rates compared with patients with bioprostheses. The former, therefore, appear to be the best valve replacement for pediatric patients.