Optimal Fat-Modified Diet Duration for the Treatment of Postoperative Chylothorax in Children

Background: Dietary modification is the mainstay of treatment for postoperative chylothorax in children. However, optimal fat-modified diet (FMD) duration to prevent recurrence is unknown. Our aim was to determine the association between FMD duration and chylothorax recurrence. Methods: Retrospective cohort study conducted across 6 pediatric cardiac intensive care units within the United States. Patients aged <18 years who developed chylothorax within 30 days after cardiac surgery between January 2020 and April 2022 were included. Patients with a Fontan palliation, who died, or were lost to follow-up or within 30 days of resuming a regular diet were excluded. FMD duration was defined as the first day of a FMD when chest tube output was <10 mL/kg/d without increasing until the resumption of a regular diet. Patients were classified into 3 groups (<3 weeks, 3-5 weeks, >5 weeks) based on FMD duration. Results: A total of 105 patients were included: <3 weeks (n = 61) 3-5 weeks (n = 18), and >5 weeks (n = 26). Demographic, surgical, and hospitalization characteristics were not different across groups. In the >5 weeks group, chest tube duration was longer compared with the <3 weeks and 3-5 weeks groups (median, 17.5 days [interquartile range, 9-31] vs 10 and 10.5 days; P =.04). There was no recurrence of chylothorax within 30 days once chylothorax was resolving regardless of FMD duration. Conclusions: FMD duration was not associated with recurrence of chylothorax, suggesting that FMD duration can safely be shortened to at least <3 weeks from time of resolving chylothorax.