Propranolol Therapy for Congenital Chylothorax.

Congenital chylothorax is a rare and often severe anomaly without well-established medical therapies. Previously, propranolol use in patients with lymphatic malformations and secondary chylothorax was associated with improvement in clinical signs. We hypothesized that propranolol treatment would be beneficial for severe congenital chylothorax. We reviewed medical records of neonates born from 2015 to 2019 at our tertiary center with a prenatal diagnosis of congenital chylothorax for whom either prenatal or postnatal propranolol therapy was initiated. Inclusion was limited to fetuses diagnosed with severe congenital chylothorax without significant genetic, infectious, or cardiac anomalies, and who underwent prenatal interventions to mitigate consequences of the condition. Propranolol was administered orally to pregnant women at 20 mg 4 times daily and increased to a maximum dose of 40 mg 4 times daily, or to infants at 0.3 mg/kg/d and increased to 1 to 2 mg/kg/d. Primary outcomes were the time course of resolution of ultrasonographical, clinical, and/or radiologic signs of chylothorax after treatment with propranolol. Four neonates met the inclusion criteria. In 2 cases, prenatal initiation of propranolol led to resolution of the chylothoraxes before delivery (38 and 32 days after treatment) on a dose of 40 mg/day 4 times daily. Neonates had a normal postnatal course. Postnatal propranolol was initiated in 2 neonates with respiratory failure when chylothoraces were refractory to standard management. Stabilization and improvement of their pleural effusion was observed by imaging at 29 and 13 days after initiation of propranolol. There were no significant maternal or neonatal complications from prenatal or postnatal propranolol use. Propranolol may be efficacious in treating severe fetal congenital chylothorax.