Bilateral bidirectional superior cavopulmonary shunt is more beneficial in medium and long term clinical outcomes than unilateral shunt

Abstract

Background The present study was aimed to compare the effects of bilateral and unilateral bidirectional superior cavopulmonary shunt (b-BDG and u-BDG) on pulmonary artery growth and clinical outcomes. Methods The 51 subjects enrolled in this study were divided into two groups: those receiving b-BDG (n=21) and those receiving u-BDG (n=30). Clinical records were reviewed retrospectively at a mean of 43.3 months after BDG procedures. Chi square and t-tests were performed to analyze the data. Results Left and right pulmonary artery diameters increased 27%-37% in both groups. The pulmonary artery index increased 37.2% after b-BDG and 27.0% after u-BDG. b-BDG patients experienced a significant decrease in mean hemoglobin concentration and hematocrit value, and a correlated change in postoperative diameter of left pulmonary artery (LPA) and pulmonary artery index (y=0.2719, x=-1.8278; R=0.564, P=0.008). The change ratio of hemoglobin and postoperative LPA were also correlated in b-BDG patients (y= -0.0522x + 0.3539; R=-0.479, P=0.028). Only one b-BDG patient versus twelve u-BDG patients needed total cavopulmonary connections 31.8 months after BDG surgery (P=0.0074). Moreover, only one (4.8%) b-BDG patient but eight u-BDG patients (26.7%) developed pulmonary arteriovenous malformations. Conclusions b-BDG increases bilateral pulmonary blood flow and promotes growth of bilateral pulmonary arteries, with preferable physiological outcomes to u-BDG. Results may imply that subsequent Fontan repair may not always be needed.