Chylothorax
Chylothorax is accumulation of lymphatic chyle in the pleural space from thoracic duct disruption or obstruction, diagnosed by a pleural fluid triglyceride above 110 mg/dL and managed with drainage, fat restriction, and duct-directed therapy when output stays high.
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What this article covers
- Overview
Chylothorax is accumulation of chyle, lymphatic fluid rich in triglycerides and chylomicrons, within the pleural space from disruption or obstruction of the thoracic duct or its tributaries.
- Epidemiology
Postoperative thoracic surgery is the leading overall cause, with esophagectomy carrying the highest risk, followed by mediastinal lymph node dissection, mediastinal tumor resection, and any surgery involving the lower neck and mediastinum.
- Risk factors
Recent thoracic or esophageal surgery, particularly esophagectomy, mediastinal lymphadenectomy, or mediastinal tumor resection.
- Pathophysiology
The thoracic duct carries chyle, the triglyceride- and chylomicron-rich lymph absorbed from the intestinal lacteals, from the cisterna chyli up through the thorax to drain into the junction of the left subclavian and internal jugular veins.
- Clinical features
Progressive dyspnea from a large, often unilateral effusion is the dominant presenting symptom, developing over days after surgery or trauma, or more insidiously with a malignant or infectious cause.
- Differential diagnosis
Cholesterol (pseudochylous) effusion: also milky, but from a chronic effusion (tuberculosis, rheumatoid arthritis) with high cholesterol (200 mg/dL) rather than high triglycerides, and cholesterol crystals on microscopy.
- Diagnosis
Chylothorax is confirmed by a pleural fluid triglyceride level greater than 110 mg/dL (1.24 mmol/L) on a fluid sample obtained by thoracentesis; this is the defining diagnostic threshold, and the…
- Management
First, place a chest tube for symptomatic or large-volume chylothorax to drain the pleural space, relieve dyspnea, allow lung re-expansion, and quantify daily chyle output, which guides every subsequent decision.
- Complications
Malnutrition and cachexia from chronic loss of protein, triglycerides, and fat-soluble vitamins in chyle, worsened when dietary restriction alone is prolonged without adequate parenteral support.
- Prognosis
Traumatic and postoperative chylothorax generally has a favorable prognosis with drainage, dietary management, and duct-directed therapy (embolization or ligation) when needed, with most cases resolving without long-term sequelae.
- Prevention
Minimize thoracic duct injury during high-risk thoracic surgery, particularly esophagectomy and mediastinal lymphadenectomy, through careful surgical technique and awareness of the duct's course near…
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