the lymph, lymph vessels and lymph
Lymphedema is a term applied to a tissue swelling that is caused by blockage of lymph flow. It is an extremely uncomfortable condition, and can be quite difficult to treat.
Lymph is a colorless fluid that oozes out of the capillaries that carry blood. It contains most of the substances and fluids that are present in blood, but has no red blood cells or platelets. White blood cells are present in the lymph. The lymph carries immune cells to cells all over the body, and carries away infections, cancer cells and debris.
After circulating through the tissues the lymph enters the lymph vessels, or lymphatics, and finds its way back into the blood through a communication at the neck. The lymph first goes into a local group of lymph nodes, then to larger groups of nodes and finally into a large duct called the thoracic duct. The thoracic ducts enter the blood.
Lymph nodes are nodules of tissue
that contain lymphocytes. They are spherical or roughly
ovoid in shape, and normally measure 1-10 mm in size.
Most lymph nodes are distributed along major arteries,
and tend to be present in groups of 10-50. Lymph produced
anywhere in the body always goes to the nearest lymph
node, where the bacteria and other foreign particles are
filtered out. The cleansed lymph passes on to the next
level of nodes, or to the blood stream. The lymph nodes
enlarge in disease. The commonest disease of lymph nodes
is lymphadenitis, or inflammation of the nodes, where the
nodes become large and painful.
Lymphedema is a term derived from "lymph" and "edema". Edema is a swelling caused by fluid, and lymphedema is a swelling in which the primary cause is a disease in the lymphatics (lymph vessels). It usually affects the legs, and is often referred to as elephantiasis. Lymphedema may occur in other parts of the body as well.
causes of lymphedema
Lymphedema is caused by a block in the lymphatics or in the lymph nodes.
Men are more often affected than women, because they are more susceptible to mosquito bites (more of the body is exposed) and to trauma. Depending upon the cause, lymphedema develops within days, months or years.
Lymphedema is characterized by a progressive swelling of the obstructed part, usually the leg. Other parts of the body that may develop elephantiasis are the scrotum (causing a hydrocele), the penis and the upper limb. Rarely elephantiasis may occur in the breast.
As the limb enlarges the skin becomes dry, thick and warty. Cracks may appear, and take long to heal. Localized infections, in particular bacterial inflammation of the lymphatics (lymphangitis), are frequent, and each attack of lymphangitis blocks more and more lymphatics.
In the early stages the limb may show pitting. Pitting is a feature in which pressure on the skin causes an indentation, much like the indentation that appears on a lump of plasticine if presssed with a finger. The indentation disappears after a minute or two. If the lymphedema has been present for long, there is so much thickening, scarring and fibrosis of the tissues that the edema does not show pitting on pressure.
The heavy limb can be the cause of pain, discomfort and can interfere with work.
Diagnosis is not usually difficult. Swelling of the limb may be caused by diseases of the veins, or lymphatics. Usually a clinical examination is enough to confirm the cause of the edema. In case further confirmation of lymphatic disease is needed, a lymphangiogram (an X-ray of the lymphatics) can be done, and it may show chronic block of the lymphatics.
If filariasis is the cause of lymphedema, it is worthwhile giving a course of diethyl carbamazine (DEC). However this will only kill any residual worms, and will not relieve the block in the lymph nodes.
Mild swelling of the legs can be controlled by tight crepe-bandages. This is a simple treatment but is somewhat cumbersome. Marked swelling needs compression therapy or surgery. Hydroceles need an operation called "excision of hydrocele". Limb lymphedema also can be treated by an operation that removes much of the swollen, diseased subcutaneous tissues, and reduces the size of the limb. Side effects of surgery are many, and wounds frequently become infected or discharge fluid. Because of the large swellings, and the thickness of skin, operative procedures are quite messy. An effective alternative is compression therapy, and is the preferred mode of management. The limb is enclosed in an inflatable rexine bag. The bag is inflated to high pressures. These ressures cannot be sustained for more than 3 minutes at a time for fear of interference with the blood supply to the limb. Sometimes both compression and surgery are required. The limb, however, will never look normal. Immediately after surgery the limb will need to be kept elevated. Compression stockings will be needed throughout life.
Patients with lymphedema may take any diet.
Diethyl carbamazine (DEC)
Patients who have swelling in the legs should always visit a doctor early, because causes of swelling other than lymphedema are actually more dangerous. Heart disease and block of the veins (deep vein thrombosis) can cause leg swelling with serious implications.
Patients known to have lymphedema must get urgent treatment when lymphangitis occurs. Lymphangitis presents as episodes of fever and redness of the limb, with pain.
Sood, MBBS (AIIMS), MS (AIIMS), MAMS, is a
practising surgeon attached to Dharamshila Cancer
Hospital, Sir Ganga Ram Hospital and to Noida Medicare
Center. Formerly Professor of Surgery, Himalayan
Institute of Medical Sciences, Dehradun, Dr Sood has a
special interest in gastrointestinal surgery. He has had
an active academic career, has published several papers
in national and international journals, and is the Editor
(with Dr Anurag Krishna) of a widely acclaimed book
titled Surgical Diseases in Tropical Countries.
Last revised: May 12, 2000