Intermediate follow-up of right ventricular outflow tract reconstruction with allograft conduits

Background. Allograft conduits are among many varieties of material used for right ventricular outflow tract reconstruction. They invariably need to be replaced due to growth of the patient or conduit failure. Methods. From June 1984 to June 1996, a total of 76 patients underwent reconstruction of the right ventricular outflow tract with an allograft conduit: 51 aortic and 25 pulmonary. The median age, weight and conduit size at surgery were 37 months (range, 0.2 to 228 months), 12.4 kg (range, 2.9 to 61.4 kg), and 17 mm (range, 8 to 26 mm), respectively. Results. The hospital mortality was 5.3% (4 of 76 patients) and 2 patients died at 9 and 78 months follow-up. The median follow-up was 61 months (range, 2 to 132 months). Reoperation was necessary in 22 patients (28.9%) at a median interval of 50.5 months (range, 3 to 109 months) and the median conduit size was 21 mm (range, 12 to 23 months). There was no mortality. Freedom from reoperation at 64 months was 49.5% for conduits 15 mm and smaller, and 73.3% for conduits 16 mm and larger. Analysis by age shows freedom from reoperation at 64 months of 49.4% and 74.5% for patients younger than and older than 2 years, respectively. At 54 months there was no statistical difference in freedom from reoperation between pulmonary and aortic allografts. Conclusion. Right ventricular outflow tract reconstruction with allograft conduits results in a high reoperation rate at 4 years but provides significantly longer freedom from reoperation with conduits larger than 15 mm or in patients over 24 months of age.