Valve replacement in children: guidelines for selection of prosthesis and timing of surgical intervention.
One hundred fifty-nine patients ranging from 3 months to 18 years old (mean, 8.1 +/- 3.7 years) underwent 162 primary valve implantations. A porcine valve was used in 104 patients, a St. Jude Medical valve in 40, and a Björk-Shiley valve in 18. The valve replaced was the aortic in 25 patients, the mitral (systemic atrioventricular [AV] valve) in 43, the pulmonary in 71, and the tricuspid (pulmonary AV valve) in 23. Hospital mortality was 6%. Patients with a Björk-Shiley valve received warfarin sodium anticoagulation, and those with a St. Jude Medical valve were given salicylates and dipyridamole. Follow-up is available on all patients 0.6 to 12 years postoperatively (mean, 6.3 +/- 2.6 years). New York Heart Association Functional Class improved in 62% and remained unchanged in 38% of the patients. Thromboembolic complications occurred in only 8 (57%) of 14 patients with a St. Jude Medical valve in the right (pulmonary) side and in 3 (12%) of 26 with the valve in the left (systemic) side of the circulation. Bacterial endocarditis developed in 3 patients, all with porcine valves. Early valve replacement, less than 2 years after detection of hemodynamic deterioration, resulted in improvement in the ventricular ejection fraction in 25 of 29 patients (from 81 +/- 14% to 90 +/- 12% of normal; p less than 0.05). In contrast, the ejection fraction remained abnormal in all 22 patients with delayed valve insertion (more than 2 years) (81 +/- 16% of normal preoperatively and 80 +/- 10% of normal following operation; p = not significant).