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What is lymphoedema?
Why is it called lymphoedema?
Why does lymphoedema occur?
Primary lymphoedema
Secondary lymphoedema
What problems can
lymphoedema cause?
How is lymphoedema
diagnosed?
What treatment is available?
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Oedema (or Edema) is a collection of fluid, so lymphoedema is a collection of lymph fluid in the body tissues.
In every person there is a small amount of fluid (lymph) in the body tissues. This is fluid that has left the blood system to provide water and nourishment to the tissues. Normally most of this fluid is collected by a system of drainage tubes, similar to blood vessels, called the lymphatic system. There is a particularly well developed system of lymphatics in the intestines (lacteals) that absorb nutrients after ingested food has been broken down.
The movement of fluid through the lymphatic system is aided by contraction of muscles and there is also a gentle pumping action from the lymphatic vessels themselves. The fluid is filtered through lymph nodes and then eventually drains back to the blood system through a major vein on the left side of the neck. Lymph only flows in one direction towards the blood system and there are tiny valves in the lymphatic channels which aid in this one way flow. There is no circulation of lymph like there is in the blood vessels.
Lymph usually moves at about 120 mls/hr and about 2-4 litres of lymph are moved around the body each day. There is great redundancy in the lymphatic system which usually operates at about one tenth of its maximum load. When lymph load is too great, fluid accumulates in tissues rather than draining back into the blood stream then lymphoedema develops.
Lymphoedema can occur for no apparent reason (Primary lymphoedema) or it can occur as a consequence of another problem (Secondary lymphoedema). Lymphoedema only affects the skin and fatty tissues and not the muscle compartments beneath.
Normal lymphatic vessels can increase the flow of lymph ten times if required. Because of this large reservoir capacity of the lymph system an increase in the formation of lymph fluid on its own does not cause lymphoedema. There must be some abnormality or problem with the lymphatic system itself.
In primary lymphoedema the lymphatic vessels themselves often appear to be abnormal. They can be very poorly developed (hypoplastic) or not developed at all (aplastic). Tiny valves in the lymphatics may also be faulty. Why this occurs is not entirely clear, but genetic abnormalities have been identified in some patients.
Primary lymphoedema can be divided into two main groups
1. Congenital onset primary lymphoedema
This can be a familial problem such as Milroy's disease which involves swelling below the knee. It may also be sporadic as in lymphatic malformations, Turner's syndrome and in other rare syndromes.
2. Post pubertal primary lymphoedema
This can also be a familial condition as in Distichiasis-lymphoedema associated with abnormalities of the eyelashes. It may also be sporadic as in inguinal node sclerosis or yellow-nail syndrome.
Lymphoedema praecox and lymphoedema tarda only refer to the age at which lymphoedema develops. Lymphoedema praecox develops in adolescence and Lymphoedema tarda generally after the age of 35 years. It is not known why normal adults, without known precipitating factors, should develop lymphoedema, but women are affected more commonly.
In secondary lymphoedema the accumulation of fluid is because of another problem.
1. Cancer and radiotherapy
After certain types of surgery (breast surgery, node dissection for melanoma) the lymphatics are intentionally removed to reduce the risk of cancer recurrence. Although in many patients other lymphatics can compensate for this loss, in some patients this is not enough and lymphoedema develops in the arm. This can also occur after radiotherapy which can damage lymphatic vessels. In patients who have had both surgery and radiotherapy there is an even greater risk of developing lymphoedema. After surgery lymphoedema may not develop immediately. It can develop gradually as the operation site heals by the formation of scar tissue. About one third of the patients who develop lymphoedema will do so more than one year after their breast cancer surgery.
In some patients the development of cancers themselves can lead to lymphoedema. This is because sometimes the tumour cells invade the lymphatic vessels, blocking them.
2. Infection
In tropical countries a tiny worm infection (filariasis) in the lymphatics can lead to massive lymphoedema (elephantiasis) of the legs and genital area. The skin also becomes very thickened and with overhanging folds which can resemble the foot of an elephant. This is because the worm is present in the lymphatic vessels and it blocks the flow of lymph fluid. Filariasis is the most common form of secondary lymphoedema worldwide.
Frequent damage to the lymphatics caused by infection (lymphangitis) can also lead to swelling because of scarring around the lymphatic channels.
In Australasia bites from insects are often blamed for persistent swelling particularly in the legs. The white-tailed spider is frequently blamed, but there is little evidence that this insect is more likely than others to lead to problems. The majority of the problems after an insect bite are probably related to the secondary infection that develops.
What problems can lymphoedema cause?
Swelling - Initially lymphoedema may only cause cosmetic concerns or heaviness and difficulty with some movements. This is because the leg (or arm) that is affected will be swollen and the skin may become slightly shiny. It also contains extra fluid so will feel heavier, because it is heavier. This may be all that happens in some patients.
Cellulitis - the presence of extra tissue fluid causing swelling in the leg can also make the patient more likely to develop infection in the tissues (cellulitis). The lymph fluid itself is very rich in protein and is an ideal fluid for bacterial growth. This can occur even after a minor injury. When this occurs the leg can swell to a greater extent. It will become red, tender and painful and the patient will probably feel generally unwell. This problem can usually be treated effectively with antibiotics, bedrest and elevation of the limb.
Fibrosis - the mere presence of significant amounts of lymph fluid in the tissues over many years can lead to scarring and fibrosis of the tissues. Once infection and inflammation resolve there will inevitably be some residual scar damage to the tissues of the leg leading to slightly more swelling than before. This puts the leg at a slightly greater risk of infection. A vicious cycle can then develop with further infection leading to further swelling and so on. It is important to try and halt this process at an early stage when most of the changes in the leg are at a reversible stage. As well as swelling due to lymphoedema, the skin can become very thickened (hyperkeratosis) and abnormal.
Tumours - very rarely tumours (lymphangiosarcoma) can develop in the chronically inflamed tissues.
The diagnosis of lymphoedema is made by your doctor taking a careful medical history and examining the affected areas. This is often sufficient to decide lymphoedema is the likely cause. Lymphoscintigraphy or lymphangiography can sometimes be used to confirm the cause and give further information.
Lymphangiography is a predominantly anatomical test outlining the channels along which lymph drains. Radionuclide lymphoscintigraphy was introduced in the 1950s and tells us much more about the function of the lymphatics and how well they are working. In most patients it is not necessary to perform either test.
Gadolinium enhanced magnetic resonance scans (MRI) are also being used in some centres and can produce impressive pictures. This is a very specialised test and few radiologists will have experience of MRI for this indication, but it has much better resolution than lymphoscintigraphy and is likely to be more sensitive and accurate (Liu et al 2010).
Sometimes other tests may be necessary to exclude other conditions. Special scans of the veins may be required to ensure they are working normally.
Treatment for lymphoedema needs to be intensive and lifelong. Lymphoedema cannot be cured, but it can be controlled. Benefits can be obtained from the treatments detailed below, but if they are stopped then problems will re-occur.
Massage and manual lymphatic drainage (MLD) - Intensive massage by practitioners trained in specific techniques helpful in lymphoedema is the initial treatment of choice, but not always widely available.
This massage is based on creating spaces in the tissues and then massaging fluid into these spaces and away from the limb. To do this the massage needs to start at the part of the limb where it attaches to the trunk where the lymphatics are relatively normal. The lymphoedema therapist then massages fluid away from this area towards the trunk. The massage then works gradually towards the hand or foot. This therapy may need to continue for some weeks until the decrease in swelling is satisfactory. It is time consuming but seems to be one of the most effective treatments.
There are different schools of massage technique each with variations that are thought to produce better results.
Compression hosiery and bandaging- Compression hosiery is crucial in maintaining the benefits produced from massage. Graduated high compression hosiery will prevent swelling re-accumulating once it has been reduced by massage. It is important that hoisery is worn at all times, except at at night. Bandaging is frequently used when swelling is severe. A combination of bandaging and massage can reduce limb size and then compression hosiery is applied.
Patients with lymphoedema usually need to wear the highest compression hosiery available either Class 3 or 4. These can be troublesome to put on, but are very beneficial in reducing swelling. It is frequently necessary to have made to measure stockings as the shape of the swollen limb may make off-the-shelf fitting impossible. Stockings require replacement approximately every 4-6 months, as they begin to lose their compressive effect.
Compression hosiery should not be used if there is significant arterial disease present.
Drugs - there is some evidence that drugs may be helpful, but they have limited value. Paroven may be of some use in some patients and is given at a dose of 3 grams daily. Coumarin has been used previously, but was withdrawn in 1998 as it caused severe liver problems in some patients.
Diuretics or water tablets that promote the passage of more urine are generally ineffective for lymphoedema. Patients will pass more urine but what fluid remains will still gravitate to the affected limb. This is because there is a local problem present leading to lymph retention and it is not due to excess fluid thoughout the whole body.
Surgery - Surgery has a very limited role in patients with lymphoedema. It is hardly ever required and will not be curative. Despite this two main types of operations have been developed. Firstly, in very particular types of patients some form of bypass or drainage procedure may be attempted to drain off the excess lymph fluid from the affected limb. Secondly, in patients with very severely affected limbs debulking operations have been performed to reduce the size of the affected limb by removing excess tissue.
Skin Care and control of infection - it is important to keep the skin in good condition. Regular hygiene particularly in skin creases and between the toes is essential. Anti-fungal powders can be helpful. Simple moisturising creams can be helpful for flaky skin. It is important to take minor wounds seriously and not to allow them to develop into serious problems. Minor infections should be treated aggressively with antibiotics.
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Liu N-F, Lu Q, Liu P-A, Wu X-F, Wang B-S. Comparison of radionuclide lymphoscintigraphyand dynamic magnetic resonance lymphangiography for investigating extremity lymphoedema. Br J Surg 2010; 97:359-365.
Last updated Saturday, 20 March, 2010 1:56 PM