Effective method of evaluating infantile chylothorax

Lymphoscintigraphy Findings are Associated with Outcome in Children with Chylothorax After Cardiac Surgery

Postoperative chylothorax in patients with congenital heart diseases (CHD) results in poor outcomes if anatomical and functional abnormalities of the lymphatic system are present. While these abnormalities are typically diagnosed by intranodal lymphangiography and dynamic contrast magnetic resonance lymphangiography, the usefulness of lymphoscintigraphy in these patients has not been evaluated. Between January 2019 and December 2021, 28 lymphoscintigraphies were performed in our institution for investigating prolonged pleural effusion after cardiac surgery. The images were assessed by three board-certified pediatric cardiologists retrospectively to determine the likelihood of a central lymphatic flow disorder. The likelihood was scored (range 1-3) based on structural abnormalities and congestive flow in the lymphatic system. Those scores were summed and the likelihood was categorized as low to intermediate (< 8 points) or high (8 or 9 points). Median age at lymphoscintigraphy was 129 days (IQR, 41-412 days), it was performed at a median of 22 days (IQR, 17-43) after surgery, and median score was 6 points (IQR, 4-7.5). Kendall's coefficient of concordance (0.867; p < 0.05) indicated high inter-rater reliability. Overall survival at 6 months after surgery was 92.5% in the low-to-intermediate group but 68.6% in the high group (p < 0.05), and duration of postoperative thoracic drainage was 27 and 58 days, respectively (p < 0.05). Lymphatic abnormalities detected by lymphoscintigraphy were associated with poorer outcomes. Lymphoscintigraphy was thought to be useful in assessing anatomic and functional lymphatic abnormalities, despite its minimal invasiveness.

Non-immune hydrops fetalis secondary to congenital chylothorax with diffuse interstitial lung disease: a diagnostic conundrum

A Chinese male infant was born at 35 weeks weighing 2935 g to a mother with polyhydramnios and prenatal hydrops fetalis. He developed marked respiratory distress secondary to bilateral congenital chylothorax and required pleural drainage, high frequency oscillation and inhaled nitric oxide therapy. He was extubated to non-invasive ventilation by day 14. There was no bacterial or intrauterine infection, haematologic, chromosomal or cardiac disorder. He was exclusively fed medium-chain triglyceride formula. High-resolution CT showed diffuse interstitial lung disease. He received a dexamethasone course for chronic lung disease to facilitate supplemental oxygen weaning. A multidisciplinary team comprising neonatology, pulmonology, haematology, interventional radiology and thoracic surgery considered congenital pulmonary lymphangiectasia as the most likely diagnosis and advised open lung biopsy, lymphangiography or scintigraphy for diagnostic confirmation should symptoms of chylothorax recur. Fortunately, he was weaned off oxygen at 5 months of life, and tolerated human milk challenge at 6 months of life and grew well.

99mTc-Dextran Lymphoscintigraphy SPECT/CT Unveils the Hidden Leakage Site in Recurrent Chylothoraxes

Chylothorax is defined as the accumulation of chyle in the pleural space, mainly by damaging to the thoracic duct. ^99mTc-Dextran is a relatively new tracer for lymphoscintigraphy. A 40-year-old woman had recurrent chylothoraxes after thymoma resection and ligation of the thoracic duct owing to intraoperative suspected thoracic duct injury. She underwent lymphoscintigraphies using ^99mTc-sulfur colloid and ^99mTc-dextran, respectively, to identify the possible leakage site of the thoracic duct. The images showed increased ^99mTc-dextran but unimpressive ^99mTc-sulfur colloid activity at the leakage site. Based on the results, this patient received surgery anastomosing the thoracic duct and the azygos vein.