Neonatal chylothorax is an abnormal accumulation of lymphatic fluid in the pleural space which can be either congenital or acquired. Nearly 90% of all in utero pleural effusions are chylothorax [1]. The estimated incidence of congenital chylothorax is 4 per lakh [2], with mortality ranging from 30-50%. [3]. We herein report a late preterm girl identified antenatally at 31 weeks of gestation with severe bilateral pleural effusion for which thoracoamniotic shunt was placed and subsequently diagnosed with congenital chylothorax after delivery.

A 37-year-old lady, G3P1A1L1 was admitted at 365/7 weeks for delivery of hydropic fetus. Antenatal follow up had been uneventful till 31 weeks when ultrasonography showed hydropic changes in the fetus with bilateral pleural effusion and subcutaneous edema. A therapeutic fetal pleurocentesis was done with amniocentesis. Chromosomal analysis and microarray on amniotic fluid was negative. Mother had a negative indirect coomb’s test, with serology negative for VDRL, and TORCH. Parvo Virus PCR was negative, and she had a normal HbA1C and Hemoglobin electrophoresis. Pleural fluid examination showed 205 leucocytes per cu.mm, 80% lymphocytes, LDH 87 U/L and a protein of 1.8g/dL. Follow up scan at 33 weeks showed a return of significant pleural effusion. Rather than opting for preterm delivery, a right Rodeck thoracoamniotic shunt was placed. Subsequent USG showed resolution of effusion on the Right side with lung expansion and satisfactory interval growth with normal fetal Dopplers. The left pleural effusion was drained just prior to the delivery.

A female baby with birth weight of 3015 g was delivered at 365/7 week gestation by elective LSCS. Baby had signs of labored breathing at birth, and was intubated and ventilated. Chest X-ray showed right side pneumothorax and left side pleural effusion for which bilateral intercostal tube drains (ICD) were inserted. Pleural fluid was clear exudate (Protein – 2.6 g/dL) with 3638 cells/mm3, predominantly lymphocytes and 1.9% neutrophils. Post ICD insertion baby improved and was extubated to high flow nasal cannula (HFNC). Echocardiography and ultrasound abdomen and cranium were normal. Once feeds were started pleural fluid became milky in nature. Pleural fluid sent for analysis showed rise in triglyceride level from baseline 35.8 mg/dL on Day 1 to 134 mg/dL on day 6 confirming the diagnosis of chylothorax.

Fig. 1 MRI image (T2 SPAIR, coronal diffusion weighted sequence) showing bilateral pleural effusion (R>L), prominent tortuous lymphatic channels in thoracic region extending into upper abdomen, with no evidence of any mediastinal mass.

MRI Chest was done on Day 8 of life for central lymphatic anatomy and intrathoracic mass lesions. It showed prominent tortuous lymphatic channels along with prominent azygous vein (Fig. 1). Baby was started on medium chain triglyceride formula on day 9 of life in view of chylothorax. Feeds had to be discontinued and parenteral nutrition restarted along with injection Octreotide on day 12 because of increasing chyle drainage. Following this, chyle formation reduced and the intercostal drains were removed on day 16. Post drain removal there was an increase in pleural effusion (right >left) which was organizing and non-tappable. Octreotide infusion was increased in view of persistent collection (at 10 mcg/kg/hr). Immunoglobulin levels were low for which single dose IVIG was given. On Day 25, lymphoscintigraphy was done to rule out lymphatic dysplasia, which was reported as normal. Feeds were restarted on day 28, after which there was worsening in respiratory distress but there was no increase in pleural effusion; as monitored by ultrasound. Keeping the possibility of leaky pulmonary lymphatics causing increase in pulmonary interstitial fluid, diuretics were added, to which baby responded well and feeds were gradually increased. Diuretics were continued till day 41 of life. Octreotide infusion was tapered gradually. Clinical exome testing done which showed no pathogenic variants causative of the phenotype, but variants of uncertain significance were detected (lymphatic malformation-3, OMIM#613480). Baby was discharged on day 44 of life on MCT- based formula (Pregestimil).

Congenital chylothorax can be an isolated finding or may be associated with genetic conditions. Early antenatal detection and management by placement of fetal pleuroamniotic shunt improves perinatal outcome by avoiding complications due to pulmonary hypoplasia [4]. Irrespective of the cause, initial postnatal management consists of drainage of pleural fluid, appropriate ventilation, total parenteral nutrition and dietary modi-fication (conservative approach). Medication and surgery may be required in refractory cases. Most chylothorax cases improve spontaneously because of the natural course of the disease. In newborns it is important to distinguish neonatal chylothorax from congenital lymphatic dysplasia, as the latter is difficult to treat and has poorer prognosis.

As increased chyle formation is associated with immunological and nutritional complications, we had started octreotide on day 12. On reviewing literature [5,6] we could not find any practice recommendations for use of octreotide. The lymphatic malformation-3 may explain the localized edema in neck, genitals and probably in lungs, which persisted at time of tapering of octreotide infusion.

To conclude, optimum management of such cases is still a matter of debate, but prenatal evaluation and management is associated with improved survival. Postnatally we should follow conservative approach for few weeks to give enough time for the lymphatics to heal and develop collaterals [6]. Refractory cases would require additional therapy.

Contributors: RS: drafted the case report and revised it critically for important intellectual content, involved with management of case; TJA: revision of case report for important intellectual content, involved with case management, approved the version to be published; SG: involved with case management, approved the version to be published.

Funding: None; Competing interest: None stated.

REFERENCES

1. Rocha G, Fernandes P, Rocha P, Quintas C, Martins T, Proença E . Pleural effusions in neonate. Acta Paediatr. 2006;95:791-8.

2. Bialkowski A, Poets CF, Franz AR. Congenital chylothorax: A prospective nationwide epidemiological study in Germany. Arch Dis Child Fetal Neonatal Ed. 2015;100:F169.

3. Dorsi M, Giuseppi A, Lesage F, Stirnemann J, De Saint Blanquat L, Nicloux M, et al. Prenatal factors associated with neonatal survival of infants with congenital chylothorax. J Perinatol. 2017;38:31-4.

4. Lee C, Tsao P, Chen C, Hsieh W, Liou J, Chou H. Prenatal therapy improves the survival of premature infants with congenital chylothorax. Pediatr Neonatol. 2016;57:127-32.

5. Bellini C, Cabano R, De Angelis L, Bellini T, Calevo M, Gandullia P, et al. Octreotide for congenital and acquired chylothorax in newborns: A systematic review. J Paediatr and Child Hlth. 2018;54:840-7.

6. Beghetti M, La Scala G, Belli D, Bugmann P, Kalangos A, Le Coultre C. Etiology and management of pediatric chylothorax. J Pediatr. 2000;136:653-8.