Definition:Â accumulation of lymphatic fluid or chyle in the pleural space (triglyceride level >1.1 mmol/l or total cell count >1000 cells/ml with >80% lymphocytes).
Congenital causes:
Lymphangiectasia, congenital heart disease, mediastinal malignancy, chromosomal abnormalities, H-type tracheoesophageal fistula.
Acquired causes:
Usually due to surgery or trauma. Post cardiac surgery incidence up to 4%, depending on type of surgery (Fontan circulation, TOF repair, HTX, BCPS) or also clot formation in the thoracic large veins.
Pathophysiological:
Chylothorax can develop because of disruption of the thoracic duct or increased pressure within the intrathoracic lymphatic system due to increased central venous pressure. Congenital causes are due to abnormal lymphatic drainage.
Complications:
Due to loss of fatty acids and lymphyocytes: hypovolemia, cellular and humoral immunodeficiency, loss of ATIII, malnutrition due to loss of lipids.
Diagnosis:
Triglyceride level >1.1 mmol/l or total cell count >1000 cells/ml with >80% lymphocytes in pleural effusion.
Treatment:
1. Conservative:Â
- Management of the underlying disease
- Dietary modification (low fat diet, medium chain triglyceride diet e.g. monogen )
- TPN only (75% respond within 2 weeks)
- Octreotide decreases splanchnic and hepatic blood flow by reducing the flow of chyle; side effects – glucose metabolism disturbance, transient hyperthyroxinemia, abdominal distension, NEC
- Immunoglobulin supplementation if needed (i.e. Di-George syndrome)
2. Surgical:
- Pleurodesis, surgical abrasion, ligation of the thoracic duct or pleuroperitoneal shunt
References:
[1] Cochrane Database Syst Rev., 2010, Sep 8: Das et all: Octreotide for the treatment of chylothorax in neonates.
[2] Ann Thorac Surg, 2005, 80, 1864 – 1871: Chan et all: Postoperative Chylothorax after cardiothoracic surgery in children
