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 (rSO ₂ ) 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 rSO ₂ 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 rSO ₂ 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 (SaO ₂ ) and the hemoglobin concentration were obtained as candidates affecting rSO ₂ changes at the start and the end of both procedures. The rSO ₂ increased during the Glenn procedure, but this increase was slight and insignificant. On the other hand, the rSO ₂ significantly increased during the Fontan procedure. Significant increases in SaO ₂ 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 rSO ₂ and SaO ₂ in both procedures. Multiple linear regression analysis showed that SaO ₂ was the key determinant of the rSO ₂ . The rSO ₂ increases step by step from the Glenn to the Fontan procedure in the same patient. Within each procedure, SaO ₂ is the key determinant of the rSO ₂ . The significance of rSO ₂ monitoring in these procedures should be further evaluated.