Lymphedema

In medicine, lymphedema exhibits as fluid retention due to damage to, or dysfunction of the lymphatic system. There may be multiple comorbid causes of fluid retention, such as metabolic disturbances.

Etiology

Lymphedema may be primary, with a genetic etiology, or secondary, as a result of another disorder or physical damage. The secondary forms are probably common, although the primary versus secondary distinction may not be important in treatment.

• "In the United States, the highest incidence of lymphedema is observed following breast cancer surgery, particularly among those who undergo radiation therapy following axillary lymphadenectomy. Among this population, 10-40% develop some degree of ipsilateral upper extremity lymphedema.
• Worldwide, 140-250 million cases of lymphedema are estimated to exist, with filariasis, infection with the parasite Wuchereria bancrofti, being the most common cause.

Secondary lymphedema

"Secondary lymphedema has an identifiable cause that destroys or renders inadequate the otherwise normal lymphatics." Besides cancer treatment or tumor effects, other causes include vein stripping for treatment of varicose veins or obtaining arterial grafts, peripheral vascular surgery, lipectomy, burns, burn scar excision, and insect bites.

Primary lymphedema

Lymphedema may have a genetic cause. Several types have been reported in the literature. They vary in in age of onset, site of edema, associated features, inheritance patterns, and underlying genetic cause. Determining the representative phenotype for different types of genetically determined primary lymphedema has been successfully achieved with Milroy's disease and the lymphedema-distichiasis syndrome. Phenotype characterization facilitates the identification of causative genes, as has been demonstrated with VEGFR3 and FOXC2, in Milroy's disease and lymphedema-distichiasis respectively.

Using transgenic and gene transfer techniques, the defects have been produced in mice, giving "initial clues to the development of a biologically based therapy for primary lymphedema. Of more importance from a public health perspective is the fact that manipulation of this pathway may lead to effective therapies for the more prevalent forms of secondary lymphedema." The known mutations leading to lymphatic phenotypes, however, explain fewer than half the cases of lymphedema. Nevertheless, there are research directions for treatment, based on lymphangiogenesis, the triggering of new lymphatic system growth.

Malformation would mean either few lymph vessels or they may be in excess. Both would cause a hindrance to the smooth working of the lymphatic system resulting in the pooling of fluids.

Milroy's disease

This is the first type of hereditary lymphedema caused as a result of inheriting a certain gene at birth. The condition is generally apparent in the legs, usually in one leg, but in some cases, it may be seen in both legs. Doctors diagnose the condition by studying the swelling present in the legs right from birth. Deeper enquiries may result in finding a family history of such type of swelling. In order to confirm the diagnosis, tests may be conducted. A dye is injected into the leg which is traced by a computer to find out where the blockages are present. Milroy's Disease is treated with decongestive therapy. Patients may experience complications like fibrosis in the limb tissues, lymphangitis or cellulitis.

Lymphedema-distichiasis syndrome

Caused by mutations in the FOXC2-gene, the lymphedema-distichiasis syndrome involves malformations of both the lymphatic and vascular systems. It "is characterized by late childhood or pubertal onset lymphedema of the limbs and distichiasis (double row of eyelashes). While the latter is the most common expression of LD, venous insufficiency occurs in half of the patients. Other associations have been reported, including congenital heart disease, ptosis, cleft lip/palate and spinal extradural cysts"

Meige's Disease

Also known as Lymphedema Praecox Meige or Hereditary Lymphedema Type II), this condition of lymphedema shows up during the teenage years and is quite a common variety of primary lymphedema. The initial indication of the genetic disorder is cleft palate.

...and the first signs of the condition are a swelling below the waist, red patches on the skin, inflammation and discomfort. Again, this hereditary lymphedema is diagnosed by observing the swelling and the family history confirming the verdict. Some other hints could be yellow nail syndrome or pulmonary hypertension. As with all other lymphedema treatments, decongestive therapy is the ideal choice here as well. Treatment must be started at the initial phase of the condition.

Lymphedema Tarda

Also known as Hereditary Lymphedema Type III /Delayed Onset Lymphedema, as the name suggests, this condition becomes apparent only after the age of thirty five. Swelling may be present in either one or both the legs. Women are more at risk for this ailment than men. Very often, family history of a similar swelling is observed.

Diagnosis

Lymphedema should be distinguished from edema, myxedema, and lipedema. Lipedema is more likely to spare the dorsum of the foot.

It is possible, however, to have comorbid edema and lymphedema. For example, a vasodilator used to treat hypertension can cause edema in a patient with cardiac disease. If that patient has had the lymphatics of the lower leg damaged by stripping the saphenous vein for use as an arterial graft, that damage can cause lymphedema to coexist with edema.

Physical examination

On physical examination, fast recovery of pitting is associated with lower serum albumin levels. Fast recovery within 2-3 seconds, is more sensitive than specific at detecting hypoalbuminemia. Presumably this is related to the viscosity of the interstitial fluid thus hypoalbuminemic interstitial fluid can reform more quickly.

Imaging

Oil contrast lymphography may be used for diagnosis. Whole-body lymphangioscintigraphy may help in the diagnosis. Magnetic resonance imaging may help in the diagnosis.

Treatment

Multilayer compression bandaging for 2-3 weeks followed by hosiery may reduce the size of limbs with lymphedema.