Changes of Cerebral Oxygenation in Sequential Glenn and Fontan Procedures in the Same Children.

Recently, it is common to perform the Fontan procedure after the Glenn procedure as surgical repair for the univentricular heart. How the brain oxygen saturation (rSO2) values change with the cardiac restoration and the process of growth during these procedures in individual children remains unknown. In this study, we retrospectively studied rSO2 data as well as the perioperative clinical records of 30 children who underwent both Glenn and Fontan procedures by the same surgeon in the same institute. The rSO2 was measured at the beginning and end of each procedure with an INVOS 5100C. Cerebral perfusion pressure was calculated by subtracting central venous pressure from mean arterial pressure. Arterial oxygen saturation (SaO2) and the hemoglobin concentration were obtained as candidates affecting rSO2 changes at the start and the end of both procedures. The rSO2 increased during the Glenn procedure, but this increase was slight and insignificant. On the other hand, the rSO2 significantly increased during the Fontan procedure. Significant increases in SaO2 were observed only between the beginning and end of the Fontan procedure. Correlation coefficients determined by linear regression analysis were more than 0.5 between rSO2 and SaO2 in both procedures. Multiple linear regression analysis showed that SaO2 was the key determinant of the rSO2. The rSO2 increases step by step from the Glenn to the Fontan procedure in the same patient. Within each procedure, SaO2 is the key determinant of the rSO2. The significance of rSO2 monitoring in these procedures should be further evaluated.