Allograft degeneration in infant pulmonary valve allograft recipients

Abstract

Infants who have undergone pulmonary valve allograft reconstruction oftheir right ventricular outflow tract (RVOT), experience an increased incidence of allograft fibrocalcification and valvar insufficiency, compared to older children. Since 1985, 137 pediatric patients havereceived a cryopreserved pulmonary valve allograft to repair their RVOT.One hundred and five patients were 1 year of age or more and 32 wereyounger than 1 year at operation. In the former group, there were 11hospital deaths (10%). Ninety-four operative survivors have been followedclinically for one month to 7.2 years (mean: 3.4 years). One patientrequired cardiac transplant secondary to myocardial dysfunction. There havebeen three late deaths (3%), and two children (2%) have undergonereoperation to replace the allograft. In the infant group, there were eighthospital deaths (25%). During 1 month to 6.8 years (mean: 2.2 years) ofclinical follow up, there have been six late deaths (25%), and fourchildren (22%) have required allograft explant. The most common indicationfor reoperation has been allograft fibrocalcification and valvarinsufficiency. The relatively high incidence of early allograft failure ininfants, which may have an immunologic etiology, has prompted considerationof nonviable allografts or low dose cyclosporine as alternatives whensurgical reconstruction of the RVOT is required in children younger than 1year of age.