Chylothorax in the perinatal period may have congenital or acquired aetiologies. In premature infants, invasive procedures with thrombosis risk are common practice. We present a case of a 29-week gestation neonate, diagnosed on the 27th postnatal day with vegetation on the tip of the central venous catheter (CVC) and right auricle thrombosis, along with superior vena cava (SVC) syndrome, leading to significant bilateral chylothorax. Despite antithrombotic therapy, extensive intramural SVC obstruction persisted. Surgical intervention was considered high risk in such a preterm infant. Lung function declined progressively, and the neonate died from cardiorespiratory failure at the age of 2 months and 26 days. A post-mortem examination revealed minimal SVC lumen obstruction, emphasizing the potential lethality of secondary complications, regardless of successful thrombolysis. This case highlights both the life-threatening risk of neonatal SVC thrombosis associated with CVC and the need to assess the causes of chylothorax for coexisting aetiologies.

Constante AD, Virella D, Lage MJ, Pinto F. Fatal Superior Vena Cava Obstruction With High-Output Chylothorax in a Preterm Infant: A Complication of Central Venous Catheterization. Cureus. 2024 Oct 12;16(10):e71296. doi: 10.7759/cureus.71296. PMID: 39529785; PMCID: PMC11552064.