[The use of cryopreserved homografts in reconstructing the right ventricular outflow tract in congenital cardiopathies].

In recent years the use of cryopreserved allograft valves has become very popular. Homograft valves have been used for aortic valve replacement and for reconstruction of the outflow tract of the right ventricle for more than 30 years with very good results. Recently the method of cryopreservation has made possible the creation of valve banks. The use of this cryopreserved valves has obtained very good short and medium term results. We present our experience with the use of cryopreserved allograft valves in the reconstruction of the right ventricular outflow tract in the treatment of complex cardiac malformations. We have operated 15 children. Six were diagnosed of different types of transpositions of the great arteries with ventricular septal defect and pulmonary atresia or stenosis. There were 2 deaths not related to the use of the allograft valves. Nine other patients were diagnosed of different types of complex cardiac malformations. One patient with a univentricular heart and pulmonary stenosis and a neonate presenting with a truncus arteriosus communis died after the operation; again the deaths were not related to the use of the homograft conduits. Our technique of cryopreservation consists in the procurement of aortic and pulmonary valves from multiorgan donor patients. The valves are sterilized in antibiotics for 48 hours. Then the process of freezing is began with a period of progressive cooling down to -40 degrees C and second phase of storage in liquid nitrogen to a temperature of -178 degrees C. The short and medium term results are very satisfactory. We have not seen late important complications.