Effect of G-Buttons on Growth Velocity Following Stage I Palliation in Patients with Hypoplastic Left Heart Syndrome

Infants with hypoplastic left heart syndrome (HLHS) who undergo the Norwood procedure are at risk for several major morbidities, including growth failure. Supplemental feeds using a nasogastric tube or gastronomy button (G-button) are often used to improve growth outcomes in HLHS patients between Norwood and Glenn. This study examines whether G-button implantation in the interstage period has a positive effect on growth velocity in patients with HLHS at a single institution. We conducted a retrospective review of patients who underwent the Norwood and Glenn procedures for HLHS from 2007 to 2017 at Cook Children's Medical Center (CCMC) in Fort Worth, Texas. Patients were excluded if they were hospitalized from Norwood to Glenn procedures, or had a G-button implanted post-Norwood discharge. Growth was assessed using World Health Organization (WHO) growth charts to calculate z-scores for body mass index (BMI), height, and weight. Mean z-scores of patients with and without G-buttons were compared from Norwood to Glenn discharge using two-tailed independent samples t-tests. Analysis of the z-scores for BMI, height, and weight revealed significantly greater weight gain in patients with G-buttons (mean=0.54, SD=0.67) from Norwood to Glenn discharge than in those without G-buttons (mean=0.07, SD=0.75; p=0.009). Additionally, compared to those without G-buttons, patients with G-buttons experienced non-significant increases in weight; there was no meaningful difference in height. Further study is required in order to discern what effect this improved weight gain may have on long term outcomes.