The impact of chylothorax on neonates with repaired congenital diaphragmatic hernia.

PURPOSE: Chylothorax is a known complication in neonates after congenital diaphragmatic hernia (CDH) repair. This report uses a large international registry to evaluate risk factors, treatment, morbidity, and survival associated with chylothorax in a prospective cohort of neonates after CDH repair.

METHODS: From January 2007 to January 2010, live-born neonates with repaired, unilateral CDHs were evaluated from a prospective database for chylothorax development. Chylothorax was diagnosed based on pleural fluid examination. Study variables included patient characteristics, CDH defect and disease severity characteristics, chylothorax treatment, and survival. In addition, the temporal relationship between timing of CDH repair and extracorporeal membrane oxygenation (ECMO) therapy was evaluated as a risk factor for chylothorax. Univariate and multivariate regression analyses were utilized.

RESULTS: Among the 1383 patients evaluated, chylothorax was diagnosed in 4.6% of the cohort. Patch repair and ECMO were statistically significant risk factors for chylothorax. The odds of developing a chylothorax were significantly increased in patients with CDH repair on ECMO (aOR 2.6; 95% CI: 1.3-4.9) or after ECMO (aOR 3.1; 95% CI: 1.7-5.8). Most chylothoraces (83.1%) were successfully treated without surgery. Chylothorax patients had significant morbidity including increased oxygen use at 30days and longer length of stay. Survival was not significantly affected by chylothorax.

CONCLUSIONS: Chylothorax is a known but uncommon complication of neonatal CDH repair. In this very large series of chylothorax in association with CDH, major risk factors appear to be related to increased disease severity with the highest risk in patients repaired on or after ECMO. Chylothoraces usually improve with conservative therapy and lead to significant morbidity but not increased mortality.