Mitral Valve Replacement With the 15-mm Mechanical Valve: A 20-Year Multicenter Experience

Background: The aim of this study was to evaluate early and long-term outcomes (mortality and prosthetic valve replacement) after mitral valve replacement with the 15-mm St Jude Medical prosthesis (St Jude Medical, St Paul, MN). Methods: A multicenter, retrospective cohort study was performed among patients who underwent mitral valve replacement with a 15-mm St Jude Medical Masters prosthesis at 4 congenital cardiac centers in The Netherlands. Operative results were evaluated and echocardiographic data studied at 0.5, 1, 2, 3, 5, and 10 years after surgery. Results: Surgery was performed in 17 infants. Ten patients (59%) were treated in the intensive care unit before surgery; 8 (47%) were on ventilator support. Median age at surgery was 3.2 months (interquartile range [IQR], 1.2-5.6), and median weight was 5.2 kg (IQR 3.9-5.7). There was 1 early cardiac death and 1 late noncardiac death. Median follow-up time was 9.6 years (IQR, 2.4-13.2), including 8 patients with a follow-up more than 10 years. The first prosthetic valve explantation (n = 11) occurred at a median of 2.9 years (IQR, 2.0-5.4). Other reinterventions were permanent pacemaker implantation (n = 3), subaortic stenosis resection (n = 2), and paravalvular leak repair (n = 1). Prosthetic valve gradients increased from a mean of 5.0 mm Hg (at discharge) to a mean of 14.3 mm Hg (at 5-year follow-up). Conclusions: Mitral valve replacement with the 15-mm prosthesis can safely be performed in infants and even in neonates. Median freedom from prosthesis replacement for outgrowth is 3.5 years. Thromboembolic complications were rare.