Lymphangiography and Lymphatic Embolization
What is lymphangiography?
Blood flows through the body through blood vessels (arteries, capillaries and veins). There are also vessels that carry fluid called lymph, which may look clear or yellow. Lymph vessels carry lymph fluid to veins, where it returns to the bloodstream.
The thoracic duct is the main lymph vessel; it carries lymph fluid from tissues and organs such as the liver and intestinal tract back into the bloodstream. Injury to the thoracic duct, congenital abnormalities or excessively high venous pressures can result in abnormalities of lymphatic flow and leakage of lymphatic fluid into the chest, abdomen or other body cavities
Lymphangiography (or lymphography) is the use of imaging, such as X-ray or MRI , to visualize the body’s lymphatic system. This allows clinicians to map the anatomy of the lymphatic system and determine the exact locations of lymphatic leaks.
A specialized technique called dynamic contrast MR lymphangiography (DCMRL) was developed by experts from CHOP. During this procedure, an MRI contrast agent is injected directly into the lymphatic system, which provides clear images of the anatomy and flow of the lymphatic system.
How are lymphatic leaks treated?
When lymphatic leaks are found, they can be sealed through two similar lymphatic interventional procedures:
- Thoracic duct embolization, in which the entire thoracic duct is embolized, or sealed shut
- Selective lymphatic duct embolization, a more targeted procedure in which the thoracic duct is spared and only certain ducts are embolized
Unlike thoracic duct embolization, in which the entire thoracic duct is occluded, in selective lymphatic duct embolization doctors will target their intervention to a specific lymphatic duct or group of ducts that have been determined by lymphangiography to be the abnormal leaky vessels. In this procedure the thoracic duct is preserved.
Experts at Children's Hospital of Philadelphia believe that this approach is vital to the procedure’s success in treating certain lymphatic flow disorders. Its targeted, noninvasive application to only the affected site may offer better outcomes for patients. Our Jill and Mark Fishman Center for Lymphatic Disorders brings together a team that specializes in the diagnosis and treatment of lymphatic flow disorders.
What to expect
During lymphangiography, the physician will place small needles into lymph nodes in the groin area. A small amount of a contrast agent (a safe, injectable dye) will be injected into the needles and tracked by MRI, X-ray or fluoroscopy as it travels upward through the lymphatic system. This allows physicians to see the anatomy of the lymphatic system, as well as the direction and speed of lymphatic flow.
In patients who will need a lymphatic interventional procedure, the physician will typically access the duct using a thin needle inserted through the abdomen. Less frequently, the physician may access the thoracic duct through a vein by catheterizing the duct where it empties into the systemic veins at the top of the chest.
The physician will then place a tiny tube (catheter) inside the duct and inject X-ray dye (contrast agent). This helps to confirm the position of the abnormality or leak. The small catheter will then be moved to the area that needs to be treated, and the leak will be embolized, or sealed, during either a thoracic duct embolization or selective lymphatic duct embolization.
Several different types of embolization agents may be used during a thoracic duct embolization or a selective lymphatic duct embolization. These agents — which include tiny metal coils, an oily contrast agent or a special glue — can be injected through the catheter to stop the leak and seal abnormal lymphatic vessels.
Children will not be awake for this procedure. We will use general anesthesia so that your child is asleep. Adults can undergo part of the procedure with local anesthesia only, but in many cases, they will be given IV sedation as well.
MR lymphangiography generally takes 1-2 hours and the embolization procedure can take an additional 1-3 hours.
After the procedure
Your experience after the procedure will depend on the type of procedure and the reason the procedure was done.
In some cases, the procedure is done as an outpatient procedure, and you or your child might be discharged after a few hours of observation. In other cases, you or your child might need to be admitted to the hospital for observation and treatment.
After the procedure, some patients may feel pain in the upper abdomen, where the needles were placed. Most postprocedural pain can be controlled with over-the-counter pain medications.
Any activity restrictions will depend on the procedure done and the cause of illness. Your medical team will discuss any necessary restrictions with you before you or your child goes home.