Clinical features and outcomes of congenital chylothorax: a single tertiary medical center experience in China

OBJECTIVE: Congenital chylothorax (CC) is an uncommon congenital disease. The objective of this study was to analyze the clinical features, treatment, and outcome of infants with CC in a Chinese tertiary medical center. METHODS: CC was defined as a non-traumatic pleural effusion with ≥ 80% lymphocytes detected before birth or within 28 days after birth. Clinical data were collected in CC infants discharged from June 2017 to March 2021. RESULTS: A total of 24 CC infants were discharged during the study period, accounting for 67% of congenital pleural effusions. The median gestational age at birth was 36(+4) weeks (range 29(+5)–41 weeks) and the birth weight was 3025 g (range 1850–4250 g). Twenty-one infants were diagnosed antenatally. The median gestational age at the time of diagnosis was 30(+3) weeks (range 24–36(+6) weeks). Nine infants presented with hydrops fetalis; 18 were bilateral. Prenatal interventions were performed in 13 fetuses. Nine infants (38%) had birth asphyxia. Compared with the infants without hydrops fetalis, the infants with CC and hydrops fetalis had lower Apgar scores at 1 and 5 min (P < 0.05) and a lower gestational age at birth (P < 0.05). Postnatally, 17 infants required continuous pleural drainage for 10 days (range 2–30 days). Analysis of the pleural effusion showed a higher cell count, lymphocyte fraction, and protein content after enteral feeding (P < 0.05). Fifteen infants required mechanical ventilation; 9 did not require any respiratory support. Ten infants received a delayed feeding strategy and 17 received a medium-chain triglyceride (MCT) formula. Only 1 infant received octreotide therapy. Twenty-one infants survived and 3 died. The main cause of death was pulmonary dysplasia. The duration of hospital stay in survivors was 21.5 days (range 10–43) days. For infants with CC and hydrops fetalis, prenatal therapy shortened the duration of pleural drainage and the length of hospital stay (P < 0.05). CONCLUSION: CC is the most common cause of congenital pleural effusions. The poor prognosis is mainly associated with prematurity, hydrops fetalis, and pulmonary dysplasia. Prenatal intervention may improve the outcome of infants with hydrops fetalis.