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, compared to older children. Since 1985, 137 pediatric patients have received a cryopreserved pulmonary valve allograft to repair their RVOT. One hundred and five patients were 1 year of age or more and 32 were younger than 1 year at operation. In the former group, there were 11 hospital deaths (10%). Ninety-four operative survivors have been followed clinically for one month to 7.2 years (mean: 3.4 years). One patient required cardiac transplant secondary to myocardial dysfunction. There have been three late deaths (3%), and two children (2%) have undergone reoperation to replace the allograft. In the infant group, there were 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%), and four children (22%) have required allograft explant. The most common indication for reoperation has been allograft fibrocalcification and valvar insufficiency. The relatively high incidence of early allograft failure in infants, which may have an immunologic etiology, has prompted 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.