Liver herniation in congenital diaphragmatic hernia is associated with delayed resolution of pulmonary hypertension.

BACKGROUND Severe and persistent pulmonary hypertension (PH) predicts mortality and short-term pulmonary morbidity in infants with congenital diaphragmatic hernia (CDH). Intrathoracic liver herniation (liver-up) is a predictor of survival and increased need for extracorporeal membrane oxygenation. There is a paucity of data on the timeline of PH resolution in infants with and without liver herniation. We aim to determine the time to PH resolution in infants with liver-up and liver-down CDH, and to describe the resource utilization among these infants.

METHODS We conducted a retrospective study of CDH infants in a quaternary neonatal intensive care unit between January 2018 and March 2021 who received targeted neonatal echocardiography (TnEcho). Our primary outcome of PH resolution was defined echocardiographically by left-to-right shunting at the patent ductus arteriosus (PDA) or rounded interventricular septum on parasternal short axis view if the PDA was closed. Serial TnEcho assessments were performed every 1-2 days around the perioperative period and then every 2-3 weeks as clinically indicated.

RESULTS Nineteen CDH infants were evaluated, of which 9 (47.4 %) infants were in the liver-up group. Baseline characteristics such as birth weight, gestational age, and sex were comparable in both groups. The median time to PH resolution was prolonged among infants with liver herniation (20.5 vs. 11.5 days, p = 0.005). The median length of stay and invasive ventilation days were longer in liver-up group (113 vs. 31 days, p = 0.017) and (19 vs. 7.5 days, p = 0.033), respectively. The proportion of infants demonstrating tube dependence for feeding at discharge was higher in the liver-up group compared with the liver-down group (8 [88.9 %] vs. 2 [20.0 %], p = 0.005).

CONCLUSION CDH infants with liver herniation experience a delayed resolution of pulmonary hypertension. Furthermore, these infants require longer hospitalization and more days on invasive ventilation.