ALLOGRAFT DEGENERATION IN INFANT PULMONARY VALVE ALLOGRAFT RECIPIENTS

Infants who have undergone pulmonary valve allograft reconstruction of their right ventricular outflow tract (RVOT), experience an increased incidence of allograft fibrocalcification and valvar insufficiency, c ompared to older children. Since 1985, 137 pediatric patients have rec eived a cryopreserved pulmonary valve allograft to repair their RVOT. One hundred and rive patients were 1 year of age or more and 32 were y ounger than 1 year at operation. In the former group, there were 11 ho spital deaths (10%). Ninety-four operative survivors have been followe d clinically for one month to 7.2 years (mean: 3.4 years). One patient required cardiac transplant secondary to myocardial dysfunction. Ther e have been three late deaths(3%), and two children (2%) have undergon e reoperation to replace the allograft. In the infant group, there wer e eight hospital deaths (25%). During 1 month to 6.8 years (mean: 2.2 years) of clinical follow up, there have been six late deaths (25%), a nd four children (22%) have required allograft explant. The most commo n indication for reoperation has been allograft fibrocalcification and valvar insufficiency. The relatively high incidence of early allograf t failure in infants, which may have an immunologic etiology, has prom pted consideration of nonviable allografts or low dose cyclosporine as alternatives when surgical reconstruction of the RVOT is required in children younger than 1 year of age.