Allograft implantation in pediatric cardiac surgery: Surgical experience from 1982 to 1994

Between July 1982 and April 1994, a total of 290 patients (median age 6.5 years, range 1 month to 32.1 years, 69 patients younger than 1 year) underwent repair of their cardiac malformation by insertion of an allograft. The diagnoses were truncus arteriosus communis (n = 78, 27.0%), tetralogy of Fallot (n = 59, 20.0%), pulmonary atresia (n = 72, 25.0%), double outlet right ventricle (n = 15, 5.0%), complex transposition of the great arteries plus pulmonary stenosis (n = 37, 13.0%), and others (n = 29, 10.0%). Either pulmonary (n = 69) or aortic (n = 221) cadaver allografts were implanted. Two hundred twentynine of the allografts were antibiotic preserved. Since January 1991 (n = 61), a new cryopreservation procedure was employed for standardized uniform cooling using heat sinks and defined package geometry. Follow-up was complete for 95.2% (n = 276,1,320 patient-years). Thirtyday mortality was 9.0% (n = 26) and late mortality was 12.1% (n = 35). Kaplan-Meier analysis revealed that patient survival was determined mainly by their underlying cardiac disease. All allografts with valve sizes less than 15.0 mm had to be exchanged within 7 years as these patients had outgrown their conduits. When the allograft was larger than 15.0 mm, exchange was necessary in 20% at 10 years. ABO compatibility and aortic or pulmonary origin of the allograft were not significant influences on allograft survival. We conclude: (1) if it is possible to implant allografts with diameters greater than 15.0 mm, allografts of either pulmonary or aortic origin are the grafts of choice for implantation into the right ventricular outflow tract; and (2) allografts with diameters less than 15.0 mm will require reoperation within 7 years. In these patients, xenograft implantation may be indicated.