Chylous ascites and Chylothorax

The lymphatic system is responsible for transporting fluid, proteins, and lipids (lymph) from our cells back into the blood stream. Accumulation of lymph into either the chest (chylothorax) or abdomen (chylous ascites) is rare. Chylous ascites and chylothorax can result from congenital abnormalities of the lymphatic system (usually as part of a more complex lymphatic anomaly, like Gorham-Stout disease or generalized lymphatic anomaly) or as a consequence of trauma.

Symptoms

Chylous ascites will cause symptoms of abdominal fullness from the excess fluid. Chylothorax will cause difficulty breathing in relation to the amount of fluid in the chest. As the lymphatic fluid accumulates in a “non-usable pocket” and not draining normally back into the blood stream it can lead to nutritional deficits from the loss of proteins and lipids. Continued loss of lymph will also affect the immune system, making infections more likely.

Diagnosis

The diagnosis of chylous ascites and chylothorax is suspected after draining the fluid as it has a characteristic milky appearance or a composition high in fat particles and lymphocytes. Laboratory tests confirm the diagnosis.

Additional imaging studies can be performed, such as MRI lymphangiography, to help find the reason for the leak of lymphatic fluid. Conventional lymphangiography using oily contrast can also be performed for diagnosis as well as potential treatment. When lymphangiography is contraindicated a nuclear medicine study, lymphoscintigraphy, can be performed.

Treatment

Nutritional supplementation and management is important for chylous ascites/chylothorax.

For congenital causes of lymphatic leak, medical and dietary therapy can be overseen by specialists in blood disorders (hematologist) and nutrition.

For traumatic or unknown causes of lymphatic leak an initial trial of dietary therapy may be all that is necessary. This can range from diet modification (high protein, low fat) to complete replacement of nutrition directly into the blood stream (total parenteral nutrition, TPN).

When nutritional measures are not sufficient, additional treatments can be applied:

• Conventional lymphangiography can be used to aid in diagnosis as well as treatment if a leak is visualized.
• Shunt placement can also be done to connect the chylous ascites or chylothorax directly to the blood stream.
• Advanced microsurgical techniques have also been developed to connect lymphatic vessels directly to veins in an attempt to restore normal flow of lymph.