What is chylothorax?
Chylothorax, is a rare lymphatic flow disorder in which lymphatic fluid leaks into the space between the lung and chest wall. When this fluid builds up in the lungs, it can cause a severe cough, chest pain and difficulty breathing. Chylothorax is part of a group of diseases characterized by abnormal circulation of lymph fluid.
The lymphatic system plays a crucial role in immune function and in the delivery of vital nutrients to the body. Functioning almost like a sponge, the lymphatic system absorbs excess lymph fluid — watery fluid containing protein, electrolytes, cells and other substances — from the body’s organs and returns it to the blood stream.
Injury to the thoracic duct (the main lymph vessel), congenital abnormalities or excessively high venous pressures can result in lymphatic flow problems and leakage of lymphatic fluid into the chest, abdomen or other body cavities.
What causes of chylothorax?
Experts in the Jill and Mark Fishman Center for Lymphatic Disorders at Children’s Hospital of Philadelphia (CHOP) are leaders in lymphatic research, diagnostics and treatment. This research is changing the way the scientific and medical communities think about chylothorax. Chylothorax can be caused by primary and secondary disorders. Regardless of the cause, our imaging allows us to determine where the leak is coming from, whether it is from the thoracic duct or channels coming from the liver perfusing into the lung.
Etiologies of Chylothorax
Primary Chylothorax
Pulmonary lymphangiectasia
- Poor pulmonary efferent lymphatic flow
- Aberrant hepatopulmonary connections
- Traumatic leak
Lymphatic Channel Disorders (Lymphatic malformations)
- RASopathies
- Central conducting lymphatic anomaly (CCLA)
- Lymphangiomatosis/Generalized lymphatic anomaly (GLA)
- Kaposiform lymphatic anomaly (KLA)
- Gorham-Stout disease (GSD)
Secondary Chylothorax
Mechanical Obstruction
- Elevated central venous pressure (CVP)
- Elevated intrathoracic pressure (ITP)
- Obstructing tumors or masses
- Thoracic duct (TD) occlusion
What are the signs and symptoms of chylothorax?
Some of the symptoms associated with chylothorax include:
- Difficulty breathing
- Cough
- Chest pain
- Hypoxia (low oxygen)
How is chylothorax diagnosed?
The world-renowned experts in the Jill and Mark Fishman Center for Lymphatic Disorders developed a specialized imaging technique — dynamic contrast magnetic resonance lymphangiography (DCMRL) — that is used to pinpoint the exact source of lymphatic leaks.
During this procedure, an MRI contrast agent (a safe, injectable dye) is injected directly into the lymphatic system and tracked by MRI.
There are three points of access through which the contrast agent is injected:
- Intranodal (inguinal lymph nodes)
- Intrahepatic (liver)
- Intramesenteric (mesentery)
Each point of access for DCMRL provides a different view of the lymphatic system for the most comprehensive lymphatic imaging. Patients with chylothorax receive all three points of access, allowing our physicians to clearly see the anatomy of the lymphatic system, the direction and speed of lymphatic flow and the exact source of any leaks. This is especially important in chylothorax diagnosis and treatment to identify the source of leak and to target an intervention.
Pulmonary lymphatic perfusion syndrome
We have found that pulmonary lymphatic perfusion leading to chylothorax fall into 6 different classifications as depicted below. (Click images to enlarge).
How is Chylothorax treated?
In the Jill and Mark Fishman Center for Lymphatic Disorders, children and adults with chylothorax are treated by the world’s most experienced specialists in lymphatic imaging and intervention. Treatment of chylothorax depends on its cause. Medications such as diuretics can be used to try and decrease the fluid in the chest along with consuming a low-fat diet. If symptoms persist, your doctor may recommend comprehensive lymphatic imaging and intervention — a selective or targeted embolization which seals off leaking lymphatic channels.
During a lymphatic embolization, several different types of embolization agents may be used. These agents — including tiny metal coils or a special glue — are injected through a catheter to stop the leaks and seal abnormal lymphatic vessels.
When lymphatic leaks are found, they can be sealed using two similar lymphatic interventional procedures:
- Selective lymphatic duct embolization, a more targeted procedure in which only certain ducts are embolized, sparing the thoracic duct which is our preferred method of intervention
- Thoracic duct embolization, during which the entire thoracic duct is embolized, or sealed shut
What is the long term outlook for patients with chylothorax?
The long-term outlook for many patients with chylothorax is very good. Nearly all patients with thoracic duct trauma can be cured. Experts at CHOP have also seen encouraging results when treating patients with other types of chylothorax. Treatment often provides a long-term cure.
Follow-up care for chylothorax
Most of the follow-up care will be done by your or your child’s primary physician in coordination with our team for special needs related to the procedure or the lymphatic disorder. This can include recommendations for new medications, medication weans or diet recommendations.
Why choose us
Our team has the most experience in the world treating both children and adults with chylothorax. We have developed a variety of innovative imaging and interventional techniques that have advanced the minimally invasive treatment options available to patients.
Publications
Savla JJ, Itkin M, Rossano JW, Dori Y. Post-Operative Chylothorax in Patients With Congenital Heart Disease. J Am Coll Cardiol. 2017 May 16;69(19):2410-2422. doi: 10.1016/j.jacc.2017.03.021. PMID: 28494978.
Weissler JM, Cho EH, Koltz PF, Carney MJ, Itkin M, Laje P, Levin LS, Dori Y, Kanchwala SK, Kovach SJ. Lymphovenous Anastomosis for the Treatment of Chylothorax in Infants: A Novel Microsurgical Approach to a Devastating Problem. Plast Reconstr Surg. 2018 Jun;141(6):1502-1507. PMID: 29794709
Vaiyani D., Saravanan M., Dori Y., Pinto E., Gillespie M.J., Rome J.J., Goldberg D.J., Smith C.L., O’Byrne M.L., DeWitt A.G., Ravishankar C. Post-operative Chylothorax in Patients with Repaired Transposition of the Great Arteries. 2021. Pediatric Cardiology. 10.1007/s00246-021-02774-z. PMID: 34841467
Srinivasan A, Smith C, Krishnamurthy G, Escobar F, Biko D, Dori Y. Characterization and treatment of thoracic duct obstruction in patients with lymphatic flow disorders. Catheter Cardiovasc Interv. 2023, Mar. doi: 10.1002/ccd.30613. Epub ahead of print. PMID 36877806
Resources to help
Jill and Mark Fishman Center for Lymphatic Disorders Resources
We know that caring for a child with a health condition can be stressful. To help you find answers to your questions and feel confident in the care you're providing your child, we’ve created this list of educational health resources.
Reviewed by Yoav Dori, MD, PhD