Postoperative pathology of complete atrioventricular defects.

Necropsy data on 15 patients, who died after operations for complete atrioventricular defect (CAVD), were reviewed in order to analyze the possible determinants of death. Two infants had undergone a palliative procedure--pulmonary artery banding (Group I); three patients had had prosthetic replacement of one or both atrioventricular (AV) valves (Groups II); and the remaining 10 had had conservative repair with plastic reconstruction of the AV valves (Group III). The most notable pathological findings related to death were as follows: Group I, left ventricular hypoplasia in both infants; Group II, prosthetic dysfunction in all patients; Group III, extracardiac diseases in two-patients and cardiac lesions in six. In Group III severe pulmonary vascular obstructive disease (PVOD) was observed as an isolated finding in two patients and in combination with residual intracardiac anomalies in another two. Analysis of the incidence of PVOD demonstrated that irreversible changes may occur within the first year of life in babies with Down's syndrome, and that these changes well correlate with the calculated pulmonary vascular resistance (PVR) values. From the results of this study we have reached the following conclusions: (1) Prosthetic valve replacement has to be avoided because of a high incidence of prosthesis-related complications and the effectiveness of conservative repair; (2) residual untreated anomalies may affect the outcome of operation and should be accurately recognized and weighted preoperatively; (3) PVOD can occur in CAVD even before the first year of life and can be reliably assessed by the measurement of PVR. High degrees of PVOD frequently interfere with the surgical success, particularly when residual intracardiac anomalies are present. Therefore, we suggest that surgical correction be planned, when indicated, during the first 6 months of life.