Discussion

Chylothorax and chylopericardium are uncommon in children, with post-operative aetiologies accounting for the majority of cases. In paediatric series, 50–70% of chylothoraces occur after congenital heart surgery, while 10–34% arise from congenital lymphatic abnormalities and fewer than 10% are associated with malignancy. ^{Reference Beghetti, La Scala, Belli, Bugmann, Le Coultre and Kalangos1,Reference Buttiker, Fanconi and Burger2,Reference Tutor5} Traumatic chylothorax is distinctly rare, representing only 1–5% of paediatric cases and approximately 2% in larger mixed-age cohorts.^{[Reference Beghetti, La Scala, Belli, Bugmann, Le Coultre and Kalangos1–Reference McGrath, Blades and Anderson4]} Most reported traumatic cases follow high-energy blunt mechanisms, particularly motor vehicle accidents and major deceleration injuries.^{[Reference McGrath, Blades and Anderson4]} Low-energy traumatic mechanisms are exceptionally uncommon. ^{Reference Tutor5–Reference Majdalany, Murthy and Jimenez8} Our case is therefore unusual, as a low-energy firecracker blast resulted in extensive lymphatic disruption leading to both chylothorax and chylopericardium.

The thoracic duct is anatomically vulnerable at the cervicothoracic junction, where it arches laterally to enter the left subclavian–internal jugular venous angle. ^{Reference McGrath, Blades and Anderson4} Even minor acceleration–deceleration or traction forces can result in microdisruption of the duct at this site, predisposing to lymphatic leakage. ^{Reference McGrath, Blades and Anderson4,Reference Tutor5} The acute swelling localised to the patient’s left neck and upper chest lies along this anatomical trajectory, further supporting a traumatic mechanism despite the apparently low-energy nature of the injury.

Accurate imaging is crucial for evaluating chylous effusions. Lymphoscintigraphy assesses functional lymphatic flow but rarely identifies specific leak sites due to low spatial resolution. ^{Reference Tutor5} More advanced modalities, including intranodal lymphangiography and dynamic contrast magnetic resonance lymphangiography, allow detailed visualisation of central lymphatic anatomy and leakage points and are increasingly used to guide therapy. ^{Reference Gómez, Baetens and Santos6,Reference Itkin and Nadolski7} Paediatric studies show high diagnostic yield with intranodal lymphangiography when conventional imaging is inconclusive. ^{Reference Majdalany, Murthy and Jimenez8} In this case, lymphoscintigraphy confirmed leakage but could not localise the defect, and dynamic contrast magnetic resonance lymphangiography was unavailable, limiting surgical options.

Initial management of chylothorax focuses on conservative therapy, including pleural drainage, dietary fat restriction or nil enteral intake with total parenteral nutrition, and adjunctive agents such as octreotide. ^{Reference Beghetti, La Scala, Belli, Bugmann, Le Coultre and Kalangos1,Reference Buttiker, Fanconi and Burger2,Reference Tutor5} While 70–80% of low-output chylothorax cases resolve with conservative therapy, high-output or persistent leaks often require escalation. ^{Reference Beghetti, La Scala, Belli, Bugmann, Le Coultre and Kalangos1,Reference Buttiker, Fanconi and Burger2} Established guidelines emphasise considering interventional or surgical treatment early when drainage remains high despite optimal medical management. ^{Reference Buttiker, Fanconi and Burger2,Reference Tutor5}

Traditionally, thoracic duct ligation has been the definitive treatment for refractory chylothorax. ^{Reference Buttiker, Fanconi and Burger2,Reference McGrath, Blades and Anderson4} However, the advent of minimally invasive lymphatic interventions—particularly thoracic duct embolisation—has transformed the therapeutic landscape. ^{Reference Gómez, Baetens and Santos6,Reference Itkin and Nadolski7} Thoracic duct embolisation allows targeted occlusion of disrupted lymphatic channels with lower morbidity compared to surgery. Paediatric series have demonstrated high clinical success rates of thoracic duct embolisation in post-operative and traumatic chylothorax. ^{Reference Majdalany, Murthy and Jimenez8,Reference Abdullah, Kakamad and Ahmed9}

In our patient, the absence of a discrete leak during lymphangiographic evaluation precluded targeted embolisation. Nevertheless, proximal thoracic duct embolisation, performed just above the cisterna chyli, is an established alternative when the leak cannot be directly visualised, as it effectively halts antegrade lymphatic flow. ^{Reference Gómez, Baetens and Santos6,Reference Itkin and Nadolski7} Despite lacking dedicated lymphatic interventional radiology services in our centre, the procedure was successfully performed by a team of paediatric interventional cardiologists. This highlights the adaptability of paediatric cardiology services in managing complex lymphatic disorders, particularly in institutions where interventional radiology lymphatic expertise is limited.

The rapid and sustained resolution of both chylothorax and chylopericardium aligns with growing paediatric evidence supporting thoracic duct embolisation as a safe and effective modality for refractory lymphatic leaks. ^{Reference Gómez, Baetens and Santos6–Reference Abdullah, Kakamad and Ahmed9}