From the Guidelines
Chylothorax is a condition characterized by the accumulation of lymphatic fluid, specifically chyle, in the pleural space surrounding the lungs, typically resulting from disruption of the thoracic duct or its tributaries. This condition occurs when the thoracic duct or other lymphatic vessels are damaged or obstructed, causing lymph fluid to leak into the chest cavity instead of flowing normally into the venous system 1. The fluid appears milky white due to its high content of triglycerides and chylomicrons from digested fats.
Causes and Diagnosis
Common causes of chylothorax include:
- Trauma (such as surgery or injury)
- Malignancies (especially lymphomas)
- Congenital abnormalities
- Inflammatory conditions
- Miscellaneous causes such as tuberculosis, sarcoidosis, and amyloidosis 1 Diagnosis involves thoracentesis with fluid analysis showing triglyceride levels above 110 mg/dL, and can be distinguished from pseudochylothorax by lipid analysis of the fluid, with true chylothorax having a high triglyceride level and the presence of chylomicrons 1.
Treatment and Complications
Treatment depends on the underlying cause and may include:
- Dietary modifications (low-fat diet or medium-chain triglyceride supplements)
- Drainage procedures
- Pleurodesis
- Surgical repair of the damaged lymphatic vessels If left untreated, chylothorax can lead to respiratory compromise, malnutrition, and immune dysfunction due to the loss of essential nutrients and lymphocytes in the chyle.
From the Research
Definition of Chylothorax
- Chylothorax is the accumulation of chyle in the pleural space, usually caused by the disruption of the thoracic duct or its tributaries 2, 3, 4, 5.
- It is characterized by the presence of chylomicrons and high levels of triglycerides in the pleural fluid 3, 4, 5.
Etiologies of Chylothorax
- Etiologies are broadly divided into traumatic, including postsurgical, and nontraumatic, most commonly in the setting of malignancy 2.
- Traumatic causes include thoracic trauma, iatrogenic injury during surgery, and traffic accidents 6, 3.
- Nontraumatic causes include malignancy, lymphatic disorders, and heart failure 3, 4.
Clinical Presentation and Diagnosis
- Clinical presentation varies, with symptoms linked to the rate of chyle accumulation and the causative condition 3.
- Diagnosis relies on pleural fluid analysis, with demonstration of elevated triglyceride levels (>110 mg/dL) and reduced cholesterol levels (<200 mg/dL) being the key diagnostic criteria employed in clinical practice 3, 4.
- Imaging modalities, including computed tomography (CT) scans and lymphatic-specific investigations, may be utilized to aid identification of the site of chyle leak and determine the likely underlying cause 3.
Management of Chylothorax
- Management is multifaceted, with conservative approaches such as dietary modification and pharmacological interventions often initiated as first-line treatment 2, 6, 3, 5.
- Drainage of chylous effusion may be necessary for symptom relief 2, 3, 5.
- When conservative methods fail, interventional procedures like thoracic duct ligation or embolization can be considered 2, 3, 5.