Purpose or Case Report: Review imaging findings on static and dynamic contrast enhanced magnetic resonance lymphangiogram (DCMRL) in young infants who presented with chylothorax and correlate these imaging findings with clinical outcomes.
Methods & Materials: A retrospective review was performed of all MR lymphangiograms (MRL) performed in infants (≤ 3 months of age) with chylothorax. Abnormal findings were identified on T2-weighted MRL and DCMRL via two-reader consensus. Review of the electronic medical record was performed to identify relevant clinical parameters.
Results: A total of 32 MRLs (15 male) were reviewed (average age 6 weeks, range 4 days-12 weeks). Inguinal node lymphatic contrast injection was performed in all cases. Intrahepatic lymphatic contrast injection was additionally performed in 10 cases. T2-weighted imaging findings included pleural effusion (100%), ascites (84%), and body wall edema (63%). Abnormal DCMRL perfusion involved: lung (53%), hilar (72%), pleural (19%), intercostal (88%), and dermal perfusion (dermal backflow 41%; subcutaneous channels 6% on inguinal injection only). The thoracic duct (TD) was visualized in 72% and partially in 13% of cases. Initial management included percutaneous (56%) and surgical (13%) intervention or conservative management (31%). 72% of children had chest tubes in place at the time of MRL. Median chest tube time was 16 days post-MRL (range 1–502 days). Chest tube presence predicted surgical or percutaneous intervention (p= 0.04), rather than conservative management. Median length of time from MRL to discharge home, transfer to another facility, or mortality was 51 days (range 1 day-2.5 years). Of the 24 children requiring respiratory support at the time of imaging, 58% weaned to room air during post MRL management. Of imaging findings, body wall edema and dermal perfusion were the biggest predictors of mortality, with a total mortality rate of 19%. Additional perfusion abnormalities and visualization of the thoracic duct did not correlate with mortality or length of hospital stay.
Conclusions: Young infants with chylothorax demonstrated abnormal perfusion of the lungs in 53%, the hila in 72%, and of the intercostal lymphatics in 88% of MRLs. Although management varied between percutaneous, surgical, or conservative care, body wall edema and dermal perfusion were the biggest predictors of mortality in these patients demonstrating the importance of imaging during initial work up.