What Is Lymphedema?
Lymphedema is an accumulation of lymphatic fluid in the interstitial tissue that causes swelling, most often in the arm(s) and/or leg(s), and occasionally in other parts of the body. Lymphedema can develop when lymphatic vessels are impaired (primary) or missing, or when lymph vessels are damaged or lymph nodes removed (secondary).
When the impairment becomes so great that the lymphatic fluid exceeds the lymphatic transport capacity, an abnormal amount of protein-rich fluid collects in the tissues of the affected area. Left untreated, this stagnant, protein-rich fluid not only causes tissue channels to increase in size and number, but also reduces oxygen availability in the transport system, interferes with wound healing, and provides a culture medium for bacteria that can result in lymphangitis (infection).
Lymphedema should not be confused with edema resulting from venous insufficiency, which is not lymph-edema. However, untreated venous insufficiency can progress into a combined venous/lymphatic disorder which is treated in the same way as lymphedema.
What Causes Lymphedema?
Primary lymphedema, which can affect from one to as many as four limbs and/or other parts of the body, can be present at birth, develop at the onset of puberty (praecox) or in adulthood (tarda), all from unknown causes, or associated with vascular anomolies such as hemangioma, lymphangioma, Port Wine Stain, Klippel Trenaury.
Secondary lymphedema, or acquired lymphedema, can develop as a result of surgery, radiation, infection or trauma. Specific surgeries, such as surgery for melanoma or breast, gynecological, head and neck, prostate or testicular, bladder or colon cancer, all of which currently require removal of lymph nodes, put patients at risk of developing secondary lymphedema. If lymph nodes are removed, there is always a risk of developing lymphedema.
Secondary lymphedema can develop immediately post-operatively, or weeks, months, even years later. It can also develop when chemotherapy is unwisely administered to the already affected area (the side on which the surgery was performed) or after repeated aspirations of a seroma (a pocket of fluid which occurs commonly post-operatively) in the axilla, around the breast incision, or groin area. This often causes infection and, subsequently, lymphedema.
Aircraft flight has also been linked to the onset of lymphedema in patients post-cancer surgery (likely due to the decreased cabin pressure). Always be sure to wear a compression garment (sleeve, stocking) when you fly, even if you do not have lymphedema.
Another cause of lower extremity lymphedema is that resulting from the use of Tamoxifen. This medication can cause blood clots and subsequent DVT (deep venous thrombosis).
Radiation therapy, used in the treatment of various cancers and some AIDS-related diseases (such as Kaposi-Sarcoma), can damage otherwise healthy lymph nodes and vessels, causing scar tissue to form which interrupts the normal flow of the lymphatic fluid. Radiation can also cause skin dermatitis or a burn similar to sunburn. It is important to closely monitor the radiated area for any skin changes, such as increased temperature, discoloration (erythema) or blistering which can lead into the development of lymphedema. Be sure to keep the area soft with lotion recommended by your radiation oncologist.
Lymphedema can develop secondary to lymphangitis (an infection) which interrupts normal lymphatic pathway function. A severe traumatic injury in which the lymphatic system is interrupted and/or damaged in any way may also trigger the onset of lymphedema. Although extremely rare in developed countries, there is a form of lymphedema called Filariasis which affects as many as 200 million people worldwide (primarily in the endemic areas of southeast Asia, India and Africa). When the filarial larvae from a mosquito bite enters the lymphatic system, these larvae mature into adult worms in the peripheral lymphatic channels, causing severe lymphedema in the arms, legs and genitalia (also known as Elephantiasis).