Lymphedema

The lymphatic system is a network that collects lymph from the organs and extremities of the body and carries it to the blood stream. This system is like the venous system of the legs and arms. There are valves in the lymphatics sending the fluid back towards the heart just as valves do in the lower extremity veins. Flow in the lymphatics results from that pressure of fluid in the area around the body cells, the negative and positive changes that occur in the abdomen and chest with breathing and movement, and the effect of muscle activity and arterial pulsations (the heart pumping blood out to the body).

Lymphedema results from poor fluid exchange and impaired transport. Proteins collect in the fluids around the body cells and pull water into this space. A buildup of lymph in these areas causes scarring and overgrowth of connective tissue. This process is similar to what happens when there is chronic inflammation. Lymph fluid clots, although more slowly than blood clots. Lymphedema can occur when there are too few, nonfunctional, or obstructed lymph pathways and/or when fluid overload overwhelms the capability of the system. When lymphedema occurs, it results in a vicious cycle that keeps high protein fluid around the cells and underneath the skin, and draws more fluid causing more scarring.

Primary lymphedema results from a congenital or inherited abnormality. Secondary lymphedema can occur from a surgical removal of lymph nodes, radiation, unknown fibrous blockages of the nodes, and/or by the invasion of the lymph vessels and surrounding tissues by threadlike parasites. One of the means by which lymphedema is classified is by its time of onset. If it is present at birth, it is called congenital. When it begins under 35 years of age, it is called praecox. If it begins after the age of 35, it is called tarda. This helps to separate acquired from congenital disease.

Lymphoscintigraphy is a diagnostic test whereby a radioactive tracer is injected into the legs. The pattern of tracer ascending up the legs defines the lymphatic return. Multiple x-rays may be taken over a 24-hour period. The skin generally turns blue. Although lymphoscintigraphy provides helpful information, it is not a routine diagnostic test.

Symptoms associated with primary lymphedema are:

• mild edema of ankles and legs along with feet and toes beginning at or around puberty;
• unilateral swelling usually involving the entire lower extremity and developing quickly (possibly associated with minor trauma such as a sprain, insect bite, or skin infection); and
• swelling of one or both legs present at birth. It is important that lymphedema not be confused with the diagnosis of chronic venous disease, although they often overlap.

The goals of treatment for lymphedema are to improve appearance and to help lessen the weight of the limb. This can be done by using external pneumatic compression. External pneumatic compression is achieved by a machine and a sleeve that fits over the limb and milks lymph flow from the foot back up towards the heart. When the limb is not being pumped, the person wears compression hose. These are designed so that maximum compression is at the ankle and compression decreases the higher up the limb it goes. Another technique is manual decongestive massage, which is more labor intensive but provides better results than pumping.

If lymphedema is severe whereby compression devices cannot be used and/or elastic stockings are unable to be worn, surgical treatment may be elected. This procedure, however, is almost never done. All skin and underlying tissue down to the muscle is removed. Skin grafting is then done to cover these areas. With this procedure, scarring is severe. Symptomatic improvement depends upon the amount of skin and tissue removed and the after surgery care aimed at promoting healing and reducing swelling.