Lymphedema

Alternative names

Lymphatic obstruction

Definition

Lymphatic obstruction involves blockage of the lymph vessels, which drain fluid from tissues throughout the body and allow immune cells to travel where they are needed.

Causes, incidence, and risk factors

There are many causes of lymphatic obstruction, which is also known as lymphedema (swelling of the lymph passages). These include certain infections (for example, chronic cellulitis or parasitic infections such as filariasis), trauma, tumors, certain surgeries, and radiation therapy. In addition, there are rare forms of congenital (present from birth) lymphedema, which probably result from abnormalities in the development of the lymphatic vessels.

In Western societies, one of the most common causes of lymphedema is mastectomy with axillary dissection (removal of the breast and underarm lymph tissue for breast cancer). This can cause lymphedema of the arm in 10-15% of patients. This occurs because the lymphatic drainage of the arm passes through the axilla (armpit), and tissue in the axilla has been removed during mastectomy.

Recurrent cellulitis, or infection of the skin, can damage lymphatic vessels and lead to lymphedema of the affected area. This is more commonly seen in obese patients.

Symptoms

Chronic swelling, usually of the arm or leg, is the clinical hallmark of lymphatic obstruction.

Signs and tests

Physical exam and history are most important for diagnosis. In some cases, lymphangiography may be performed. This involves injection of dye into lymphatic vessels followed by x-rays of the area. Lymphangiography requires surgical isolation of the lymph vessels to be injected and is therefore a difficult procedure.

Lymphoscintigraphy is an alternative technique in which a radioactive substance that concentrates in the lymphatic vessels is injected into the affected tissue and mapped using a gamma camera, which images the location of the radioactive tracer. Lymphoscintigraphy is less invasive and more easily performed and is often used as a substitute for lymphangiography.

MRI is being explored as a means to image lymphatic vessels.

Treatment

The mainstays of therapy for lymphedema include range of motion exercises, compression (usually with multi-layered bandages), and manual lymph drainage (MLD). A physical therapist trained in these techniques is the appropriate person to see for treatment. Manual lymph drainage is a light massage therapy technique that involves moving the skin in particular directions based on the structure of the lymphatic system. This helps encourage drainage of the fluid and waste through the appropriate channels.