Section 3. Heart and Blood Vessel Disorders

Chapter 37. Lymphatic Disorders

Topics: Introduction | Lymphedema | Lymphadenitis | Acute Lymphangitis

Lymphedema

Lymphedema is the accumulation of lymph resulting in swelling.

Lymphedema differs from accumulation of fluid (edema) due to venous insufficiency, which develops when blood that is backed up in veins causes fluid to leak from blood vessels into tissues. Edema may be caused by heart failure (see Section 3, Chapter 25), but lymphedema is not. Lymphedema results when an abnormality prevents lymph from being reabsorbed into the capillaries as it normally is. As a result, the lymphatic system cannot adequately drain lymph from the tissues.

Lymphedema may be due to conditions present at birth (congenital) or to conditions that develop later (acquired).

Congenital lymphedema results from having so few lymphatic vessels that they cannot handle all the lymph. The problem almost always affects the legs; rarely, it affects the arms. Women are much more likely than men to have congenital lymphedema.

Rarely, the swelling is obvious at birth, but usually, the lymphatic vessels can handle the small amount of lymph produced in an infant. More often, the swelling appears later in life, as the volume of lymph increases and overwhelms the small number of lymph vessels. The swelling starts gradually in one or both legs. The first sign of lymphedema may be puffiness of the foot, making the shoe feel tight at the end of the day. The shoe may leave indentations in the skin of the foot. (Many people who do not have lymphedema experience swelling after they stand for prolonged periods. They may have indentations around their ankles after they wear ankle socks, but the indentations are much less deep than those of lymphedema, and the surrounding area is not puffy.)

In the early stages of congenital lymphedema, the swelling goes away when the leg is elevated. This disorder worsens with time: The swelling becomes more obvious and does not disappear completely, even after a night's rest.

Acquired lymphedema is more common than congenital lymphedema. It typically appears after major surgical treatment, especially after cancer treatment in which lymph nodes and lymphatic vessels are removed or treated with radiation. For example, the arm tends to swell after removal of a cancerous breast and the associated lymph nodes. Scarring of repeatedly infected lymphatic vessels may also cause lymphedema, but this type of scarring is very uncommon except among people who have an infection due to the tropical parasite Filaria (filariasis).

In acquired lymphedema, the skin looks healthy but is puffy or swollen. Pressing the area with a finger does not leave a significant indentation, as it does when edema results from inadequate blood flow in the veins. Rarely, especially in filariasis, the swollen limb becomes extremely large and the skin is so thick and ridged that it looks almost like elephant skin. This disorder is called elephantiasis.

Treatment

Lymphedema has no cure. For people with mild lymphedema, compression bandages can reduce the swelling. People who are more severely affected may wear pneumatic stockings (see Section 3, Chapter 36) every day for an hour or two to reduce the swelling. Once the swelling has been reduced, the person must wear elastic stockings up to the knee every day from the moment of rising until bedtime. This measure controls the swelling to some degree. For lymphedema in the arm, pneumatic sleeves--like pneumatic stockings--can be used every day to reduce the swelling; elastic sleeves are also available. For elephantiasis, an extensive operation may be performed to remove most of the swollen tissues under the skin.