PULMONARY ARTERIAL CHANGES IN PATIENTS DYING AFTER A MODIFIED FONTAN PROCEDURE FOLLOWING PULMONARY-ARTERY BANDING

Pulmonary arterial changes were histometrically analyzed in four cases of postoperative death following a modified Fontan procedure in which pulmonary artery banding had previously been performed because of pul monary hypertension. Case 1 was a 3-year-old girl with corrected trans position of the great arteries (TGA), ventricular septal defect, and d ouble-inlet left ventricle; case 2 was a 6-year-old girl with single v entricle (SV) and complete TGA; case 3 was a 25-month-old boy with SV and double-outlet right ventricle; and case 4 was a 21-year-old man wi th tricuspid atresia. The cause of death in cases 1, 2, and 3 was pulm onary hypertensive crisis due to postoperative vasoconstriction of the small pulmonary arteries. Medial hypertrophy remained in half of the preacinar small pulmonary arteries although it was not observed in all the intraacinar arteries in cases 1 and 2, even after banding. The po stoperative course of case 4 was uneventful despite multiple thromboem bolism in the small pulmonary arteries. However, the patient died due to a thrombosed artificial valve. The results suggest that residual me dial hypertrophy of the small pulmonary arteries was a major risk fact or in these cases. Lung biopsy is recommended to determine the indicat ions for the Fontan procedure in these hemo-dynamically critical cases .