Valve replacement in children less than 5 years of age.

Between 1966 and 1984, there were 63 children less than 5 years of age who underwent 70 valve replacements (49 mitral [5 repeat], 6 aortic, 11 tricuspid [systemic ventricle; 2 repeat]), 2 tricuspid [pulmonary ventricle] and 1 multiple [mitral-aortic]) at Children's Hospital. Tissue valves were used in 20%. Since 1980, only Björk-Shiley and St. Jude valves have been used. The most common indication for valve replacement was mitral regurgitation after repair of atrioventricular (AV) canal (34%). Mortality dropped considerably over time: 76% before 1979, 33% from 1979 to 1982 and 22% since 1982. More than two-thirds of fatalities were operative deaths, usually within 3 days of surgery. Actuarial survival curves for those operated on since 1980 predict 1 and 5 year survival of 73 and 51%, respectively. For the 46 operative survivors 1 and 5 year valve survival was 97 and 70%, respectively. Postoperative hemodynamics were significantly improved on elective postoperative catheterizations. All but one patient with non-tissue valves received anticoagulant therapy. Postoperative complications included thromboembolism (1.6/100 patients-years) and hemorrhage (0.8/100 patient-years). The frequency of intravascular hemolysis and endocarditis was 1.6%, comparable with adult experience. Complete heart block requiring a pacemaker developed in nine patients (14.1%), in all after AV valve replacement. Valve replacement in young children generally results in considerable hemodynamic improvement. The mortality rate remains above that observed in adults but has declined considerably for those operated on after 1980.