Mitral valve replacement with mechanical prostheses in children: improved operative risk and survival

Objective: The purpose of this study was to assess the early and late outco me following mitral valve replacement (MVR) with mechanical prostheses in c hildren. Patients and methods: Between 1981 and 2000, 44 consecutive childr en (mean age 6.8 +/- 4.7 years, 2 months-16 years) underwent mechanical MVR in Southampton. Twenty-three children were less than 5-years-old and nine were infants. Disease aetiology was congenital in 37, rheumatic in four, in fective in two and Marfan's syndrome in one. Mitral regurgitation was prese nt in 36 and mitral stenosis in eight. Concomitant procedures were performe d in 13, including aortic valve replacement (AVR) in seven. Follow-up was c omplete (mean 6.4 +/- 4.8 years, 1 month-18.1 years). Results: The overall operative mortality was 14% (six patients). Before and after 1990 operative mortality was 31 vs 3.6% (P = 0.02). From 1990, operative mortality for in fants was zero out of six, for children less than 5-years-old was one out o f 16 (one death after emergency AVR and MVR) and for older children it was 0/12. Seven children experienced valve or anticoagulation treatment-related events and eight had a mitral valve re-operation. Ten-year freedom from th romboembolism, prosthetic valve infection, bleeding, paravalvular leak and a mitral valve re-operation was 92.8 + 5.2, 97.3 +/- 2.7, 97.7 +/- 2.3, 97. 2 +/- 2.7 and 75 +/- 9.7%, respectively, Overall 10-year survival was 78 +/ - 7% (four late deaths); for children under vs over 5 years it was 61 +/- 1 1 vs 95.2 +/- 4.6% (P = 0.02), for atrio-ventricular septal defect (AVSD) v s other pathology 55 +/- 15 vs 89 +/- 6.1% (P = 0.05) and for those operate d before 1990 vs after 1990 it was 63 +/- 8.1 vs 86 +/- 8.2% (P = 0.04). Co nclusions: Mechanical MVR, in the current era, carries a low operative risk across the spectrum of paediatric age. Late survival is better for older c hildren and those having no-AVSD pathology but it has improved substantiall y during the 1990s irrespective of age and disease aetiology. (C) 2001 Else vier Science B.V. All rights reserved.