Appropriate Additional Pulmonary Blood Flow at the Bidirectional Glenn Procedure is Useful for Completion of Total Cavopulmonary Connection

Background The role and effect of additional pulmonary blood flow at the time of bidirectional Glenn procedure (BDG) is controversial. We assessed our experiences to clarify the effects of controlled additional pulmonary blood flow on outcomes after BDG. Methods Thirty-eight patients who underwent BDG (2.1 ± 2.1 years of age) were enrolled in this study. In group A (n = 29) additional pulmonary blood flow was controlled by the banding of the pulmonary trunk, or the previously created Blalock-Taussig shunt, to keep the central venous pressure equal to or less than 16 mm Hg at BDG. In group B (n = 9), BDG was the only source of pulmonary blood flow. Results One operative death occurred in group B. In group A, 24 patients underwent total cavopulmonary connection (TCPC) 14 ± 6 months after BDG, and the remaining 5 patients are waiting for TCPC in good condition. In group B, 6 patients underwent TCPC 8 ± 7 months after BDG. One patient is awaiting TCPC and the remaining patient is considered unsuitable for TCPC. Cardiac catheterization performed in 32 patients showed significant decrease of pulmonary artery (Nakata) index from 307 ± 73 to 215 ± 45 mm2/m2 after BDG in group B (p< 0.05). On the other hand, the Nakata index stayed in higher range from 316 ± 115 to 287 ± 74 mm2/m2 in group A, and there was a significant correlation between the Nakata index and the percentage of its difference (Y = 40.823 − 0.144 X; n = 26, R = 0.740, p< 0.0001). Conclusions Appropriate additional pulmonary blood flow is useful for the completion of TCPC by means of suppressing the decrease in the size of the pulmonary artery, especially in patients with underdeveloped pulmonary arteries.