and Lymph Drainage
Swelling of the tissue may occur after an injury or post surgery around a joint or in the whole limb. It can also be more generalized or systemic due to heart or kidney issues as well as specific for conditions such as lymphedema.
Lymphedema, also known as lymphatic obstruction, is a condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system.
The lymphatic system returns the interstitial fluid to the thoracic duct and then to the bloodstream, where it is recirculated back to the tissues.
Tissues with lymphedema are at risk of infection.
Lymphedema may be inherited (primary) or caused by injury to the lymphatic vessels (secondary). It is most frequently seen after lymph node dissection, surgery and/or radiation therapy, in which damage to the lymphatic system is caused during the treatment of cancer, most notably breast cancer. In many patients with cancer this condition does not develop until months or even years after therapy has concluded. Lymphedema may also be associated with accidents or certain diseases or problems that may inhibit the lymphatic system from functioning properly. In tropical areas of the world, a common cause of secondary lymphedema is filariasis, a parasitic infection. It can also be caused by a compromising of the lymphatic system resulting from cellulitis.
While the exact cause of primary lymphedema is still unknown, it generally occurs due to poorly-developed or missing lymph nodes and/or channels in the body. Lymphedema may be present at birth, develop at the onset of puberty (praecox), or not become apparent for many years into adulthood (tarda). Some cases of lymphedema may be associated with other vascular abnormalities. Lymphedema affects both men and women. In women, it is most prevalent in the upper limbs after breast cancer surgery and lymph node dissection, occurring in the arm on the side of the body in which the surgery is performed. It may also occur in the lower limbs or groin after surgery for colon, ovarian or uterine cancer in which removal of lymph nodes is required. In men, lower-limb primary lymphedema is most common, occurring in one or both legs. Surgery and/or treatment for prostate, colon and testicular cancers may result in secondary lymphedema, particularly where lymph nodes have been removed or damaged.
The onset of secondary lymphedema in patients who have had cancer surgery has also been linked to aircraft flight (likely due to decreased cabin pressure). For breast cancer survivors, wearing a prescribed and properly-fitted low-compression sleeve and gauntlet may help decrease swelling during flight.
Some cases of lower-limb lymphedema have been associated with the use of Tamoxifen, due to the blood clots and deep vein thrombosis (DVT) that can be caused by this medication.
A leading vascular surgeon once described lymphedema as “a plumbing problem.” Not exactly medical jargon, but when you consider the role of the lymphatic system and what happens when it gets blocked up, it does seem to fit.
The Lymphatic System
Most of us are familiar with the circulatory system – the veins, arteries and capillaries that move blood to and from all the places in our body. The arteries carry oxygenated blood from the lungs, along with nutrients, to all the cells in the body. They end in capillaries that nourish the tissue. The capillaries then lead to the veins, which return the depleted blood back to the lungs.
The lymph vessels are also an important part of the circulatory system. As the blood flows through the capillaries, it is under pressure. Because of this pressure, fluid and proteins seep out of the arterial side of the capillaries. The tiny lymph capillaries pick up these lost fluids and proteins and transport them through progressively larger lymph vessels. As this “lymph fluid” flows through the lymph vessels, it is filtered through lymph nodes, where white blood cells remove bacteria and other foreign materials. The fluids are then returned to the blood stream. We can think of the lymph vessels as the body’s “water system,” with “watersheds” where the smaller lymph vessels drain off directionally into bigger collectors, and “purification stations” at the lymph nodes.
The amount of fluid processed by the lymphatic system is truly huge. At any one time, nearly 90% of the water found in our blood is being filtered through the lymphatic system. In cases of overload, such as injury or infection, healthy lymphatic vessels can absorb up to ten times their usual capacity. But when the lymphatic system is malformed or damaged, blockages can result. The lymphatic fluids from that particular area “serviced” by the blocked channel cannot be transported adequately. Excess fluids build up and produce swelling. In addition, the proteins that leach out of the arterial capillaries build up in this fluid, attracting even more water as the body seeks to maintain its osmotic balance. This causes further swelling.
This condition is called lymphedema, and can appear in various parts of the body, but most often affects the arms or legs. The swelling can cause the affected limb to become extremely large and heavy, causing disfigurement and disability. Chronic inflammation causes fibrosis, a hardening of the surrounding tissues, making the drainage process even more difficult. The stagnant lymph fluid also provides ideal growing conditions for bacteria that lead to infection.
So people with lymphedema must maintain a strict regimen of skin care, avoiding any wounds or abrasions that might allow entry to bacteria or other pathogens. People with lymphedema must be on guard for systemic infections such as cellulitis that can make them extremely ill.
Causes of lymphedema
Lymphedema can be caused by malformed or inadequate lymphatics – an inborn defect. In keeping with our “plumbing” theme, you can think of a faulty pipe system – not enough pipes, or pipes with the wrong shape or made from the wrong materials. This type of lymphedema is called primary lymphedema.
Primary lymphedema can be evident from birth, when the baby is born with a swollen arm or leg, or it can develop later in adolescence or even in adulthood. Congenital lymphedema appears at birth. Milroy’s disease is a familial, or inherited, form of congenital lymphedema. Lymphedema praecox appears before the age of 35, usually during adolescence. Primary lymphedema that appears after the age of 35 is called lymphedema tarda.
Secondary lymphedema, sometimes called acquired lymphedema, is caused by blockage or disruption of the lymphatic vessels due to disease or trauma.
Examples of secondary lymphedema include those caused by mastectomy surgery and/or radiation (postmastectomy lymphedema); other surgeries, especially cancer surgeries with lymph node removal; tumors pressing or blocking the lymphatic vessels; trauma due to accidents, and occasionally as a result of liposuction surgery. Filariasis, a parasitic infection, is a frequent cause of secondary lymphedema in tropical countries.