Mitral valve replacement in children: Mortality, morbidity, and haemodynamic status up to medium term follow up

Objective-To investigate the outcome of mechanical mitral valve replacement in children after up to 11 years of follow up. Design-Retrospective analysis of case records. Operative survivors underwen t echocardiographic studies to define current haemodynamic status and prost hetic valve function. Setting-Tertiary referral centre. Patients-All 54 children who underwent mitral valve replacement between Jan uary 1987 and December 1997. Results-30 day mortality was 20.3% and was associated with small valve size and supra-annular position. The actuarial freedom from the following event s at five years (70% confidence interval (CI)) was: death, including 30 day mortality and transplantation, 68% (70% CI 62% to 75%); bleeding, 89% (70% CI 84% to 94%); non-structural valve dysfunction and reoperation, 92% (70% CI 87% to 97%). The incidence of endocarditis and thromboembolism was low and there was no structural valve failure. Event-free survival was 52% (70% CI 45% to 600/0). Low weight, young age, and small valve size increased th e chance of death or reoperation. On echocardiography, left ventricular dil atation and wall motion abnormalities were often observed. A high mean grad ient over the prosthesis was associated with small valve size but not with length of follow up. Conclusions-With the use of mechanical prostheses for mitral valve replacem ent in children, the problem of structural valve failure is no longer an is sue. However, the procedure is still associated with a high complication ra te, both at surgery and during follow up, and should therefore be reserved for patients in whom valve repair is not technically feasible.