Lymphangiography is a type of diagnostic testing technique in which x rays (called lymph node angiograms) and the injection of a contrast medium (a substance that provides a contrast between the tissue or organ being filmed and the medium) are used to visualize lymphatic circulation and the lymph nodes.
The lymphatic system consists of tissues, organs, and vessels that aid in circulating body fluids and defending the body from damage by foreign substances such as viruses, bacteria, or fungi. However, certain cancers may also spread through the lymphatic system. Thus, lymphangiography is sometimes used to:
- diagnose the presence or spread of tumors, lymphatic cancer (lymphoma), and other cancers
- distinguish primary lymphedema (when swelling in the lymphatic system arises from missing or impaired lymphatic vessels) from secondary lymphedema (swelling caused by damaged lymph vessels or lymph nodes that have been removed)
- localize tumors for surgical removal
- assess the effectiveness of chemotherapy and radiation therapy in treating problems associated with metastatic (spreading) cancer
Although the results of lymphangiography are considered reliable, additional tests, studies, and clinical observations are necessary to determine a precise diagnosis. By itself, lymphangiography misses cancer in about 20% of cases. One of the major drawbacks of lymphangiography is its failure to fill certain lymphatic channels and groups of lymph nodes—a failure that may be due to infection, injury, or tumor spread. When this filling failure occurs, certain segments of the lymphatic system in the abdomen and pelvis cannot be visualized; thus, metastatic disease can be neither confirmed nor ruled out.
Since the late 1990s, conventional lymphangiography (using an iodine oil-based contrast agent) has been used almost exclusively for the staging of urologic pelvic and testicular malignancies. The test may demonstrate metastases within lymph nodes of normal size that are missed on computed tomography (CT) imaging. Technical innovations in nuclear diagnostics and computer imaging largely replaced lymphangiography with simpler, safer, and more reliable techniques of visualizing the lymphatic system (such as lymphangioscintigraphy, or isotope lymphography).
Because of the possibility of an adverse reaction to the contrast medium, lymphangiography is usually not administered to patients with lung problems, heart disease, or severe kidney or liver disease.
Individuals with allergies to shellfish, iodine, or dye used in other diagnostic tests may receive steroids or antihistamines before the test to decrease the risk of allergic reactions.
Lymphangiography testing may be done on an inpatient or outpatient basis. A sedative may be given to help the patient relax. After the skin of each foot is cleaned with an antiseptic, a blue indicator dye (which does not show up on x rays) is injected between the first, second, and third toes of each foot. The dye spreads into the lymphatic system in about 15 to 30 minutes. The thin, bluish lines that appear on the top of each foot delineate the lymphatic vessels. Next, a local anesthetic is injected, and a small incision is made into one of the larger blue lines in each foot. A needle or catheter (a thin flexible tube) is inserted into a vessel in each foot, and an oil-based contrast medium (such as Ethiodol) is injected at a slow, steady rate. A feeling of pressure may occur as the contrast medium is injected, but the patient must lie still to avoid dislodging the needle.
A fluoroscope (a device consisting of a fluorescent screen on which the shadows of objects that come between the screen and an attached x-ray apparatus can be viewed) is used to monitor the progress of the contrast medium as it spreads slowly (taking about 60 to 90 minutes) through the lymphatic system, traveling up the legs, into the groin, and along the back of the abdominal cavity. After the contrast agent is injected, the catheter is removed and the incisions are stitched and bandaged. Then x rays are taken of the legs, pelvis, abdomen, and chest areas. The following day, an additional set of x rays is obtained.
After the test, the patient's skin, feces, and urine may have a bluish tint for two to three days (until the marker dye disappears), and there may be some discomfort behind the knees and in the groin area. Test results are reported to the doctor or patient from a few hours to a few days after the procedure.
There is usually no special preparation needed before lymphangiography—such as restrictions in diet, activity, or medication intake. However, some facilities may require a clear liquid diet for a specified period of time before the test. In addition, for comfort reasons, patients may be asked to empty their bladder before testing. A patient undergoing lymphangiography (or a close family member) must sign a consent form before the test is administered.
After testing, the patient's blood pressure, pulse, breathing status, and temperature are monitored at regular intervals until they are stable. Any lung complications are noted, such as hoarseness or shortness of breath, chest pain, low blood pressure, low-grade fever , and blueness of lips and nailbeds due to clotting of the dye.
Bedrest for at least 24 hours following the test is recommended, with feet elevated to help reduce swelling at the incision sites. The incision sites may be sore for several days, and ice packs may be applied to these sites to further reduce swelling. The patient should also inspect the incision sites for infection. Sterile dressings should remain in place for two days, and the incision sites should be kept dry until after the sutures are removed (7 to 10 days after the test).
There is a risk of infection or bleeding caused by introducing the needle or tube through the skin or an allergic reaction—usually not serious— to the contrast medium. There is also a slight risk of oil embolism (obstruction of a blood vessel) due to the oil-based contrast medium. The contrast medium eventually seeps from the lymphatic channels into the general circulation, where it may travel to, and lodge in, the lungs.
There is some radiation exposure involved in the procedure. Although pregnant women and children are particularly sensitive to these risks, physicians may order the procedure when the benefits appear to outweigh the risks.
Normal test results indicate no anatomical or functional abnormalities.
Abnormal results may indicate:
- Filariasis (a tropical disease caused by worms living in the lymphatic system)
- Hodgkin's or non-Hodgkin's lymphoma (cancers of the lymphatic system)
- metastatic cancer
- primary lymphedema
- retroperitoneal tumors (tumors lying outside of the peritoneum—the membrane lining the abdominal cavity)
Fischbach, Frances Talaska. A Manual of Laboratory and Diagnostic Tests, 6th ed. Philadelphia: Lippincott Williams and Wilkins, 2000.
Pagana, Kathleen Deska, and Timothy James Pagana. Mosby's Manual of Diagnostic and Laboratory Tests. St. Louis, MO: Mosby, 1998.
Schull, Patricia, ed. Illustrated Guide to Diagnostic Tests, 2nded. Springhouse, PA: Springhouse Corporation, 1998.
Zaret, Barry L. The Patient's Guide to Medical Tests: Every thing You Need to Know About the Tests Your Doctor Pre scribes. New York: Facts on File, Inc., 1998.
Bellin, Marie-France, Catherine Beigelman, and Sophie Precetti-Morel. "Iron Oxide-Enhanced MR Lymphography:Initial Experience." European Journal of Radiology, (June 2000): 257-264.
Winterer, Jan Thorsten, Ulrich Blum, Stephan Boos, Stavros Konstantinides, and Mathia Langer. "Cerebral and RenalEmbolization After Lymphangiography in a Patient withNon-Hogkin's Lymphoma: Case Report." Radiology (February 1999): 381-385.
American College of Radiology, <http://www.acr.org>.
Lymphoma Research Foundation of America <http://www.lymphomafocus.org>.
Genevieve Slomski, Ph.D.
QUESTIONS TO ASK THE DOCTOR
- What is the purpose of the test?
- How long will the test take?
- Will I be sedated or get anesthesia before the test?
- Is there anything special I need to do before the test?
- Can I drive myself home after testing?
- When will I get the results?
—A substance that provides a contrast between the tissue or organ being filmed and the medium.
—A rounded, encapsulated body consisting of an accumulation of lymphatic tissue; found in lymphatic vessels.
—A type of lymphatic cancer.
—Cancer cells that have spread from the primary site of malignancy to another location in the body.
Lymphangiography, or lymph node angiogram, is a test which utilizes x-ray technology, along with the injection of a contrast agent, to view lymphatic circulation and lymph nodes for diagnostic purposes.
The lymphatic system is a one way circulation that channels tissue fluid back into the heart. The watery fluid called lymph seeps out of the blood into tissues, and while journeying back to the heart, it picks up germs, cancer cells, and some waste products. Lymph passes through the lymph nodes, which are major arsenals of immune defense that attack germs carried in the lymph. Cancer cells are also subject to attack in lymph nodes.
Cancers of the lymph system, such as Hodgkin's disease and non-Hodgkin's lymphomas, spread throughout the body. Treatment often depends upon finding all the disease and directing radiation to each location. Planning other kinds of treatment, such as surgery or chemotherapy, may also require that the full extent of the disease be known.
The lymphatic circulation may become clogged by infection, injury, or several other types of cancer that have spread through lymphatic channels. Swelling, sometimes massive, can result from blocked lymphatics. The most outstanding example of this is the tropical disease filariasis, which results in the swelling of the legs termed elephangiasis.
Lymphangiography gives precise information on the extent and location of lymph vessels and lymph nodes. Oftentimes, it is performed to evaluate the extent of a lymphatic cancer. Rarely, it is a tool, which aids surgeons attempting to reconstruct the lymphatics.
Lymphangiography should not be performed on patients with dye or shellfish allergies or on patients with chronic lung disease, kidney disease, heart disease, or liver disease.
A lymphangiogram begins by injecting a blue dye into a hand or foot. The lymph system picks up dye, which in turn will highlight the lymph vessels. This process may take a full day. When the lymphatic channel is clearly visible, the radiologist will insert an even tinier needle into that vessel and inject a contrast agent. X rays outline the journey of the contrast agent as it travels to the heart through lymph vessels and nodes.
Unless a dye allergy is suspected, no special preparation is need. If an allergy is suspected, a non-ionic contrast agent can be administered instead.
Contrast agent— A substance that makes shadows on x rays.
Filariasis— A tropical disease caused by worms that live in lymph channels.
Hodgkin's disease— A cancer of the lymphatic system.
Lymphoma— A type of lyphatic cancer.
Prior to suture removal seven to 10 days after the procedure, the patient should watch for any sign of infection around the site.
Lipid pneumonia can occur if the contrast agent penetrates the thoracic duct. An allergic reaction to the contrast agent is possible, causing a range of symptoms that can range from innocuous to life threatening.
Merrill, Vinta. "Lymphangiography." In Atlas of Roentgenographic Positions and Standard Radiologic Procedures. Saint Louis: The C. V. Mosby Co., 1975.