Lymphoedema is the chronic swelling of one or more body parts, most commonly an arm or leg . Lymphoedema develops when excess fluid (lymph) fails to be drained away from the tissues due to the lymphatic system (a drainage system for the body) being damaged, blocked or defective. So this fluid continues to collect in the tissues beneath the skin of the body part that the damaged lymphatic would normally drain and transport away. This build up of fluid is seen as swelling, known as lymphoedema. In the last issue of “Lymphformation”, we focused on Primary Lymphoedema, where there is a congenital defect or abnormality of the lymphatic vessels themselves, and where there appears to be no obvious reason why the lymphoedema arises. Secondary lymphoedema is much more common than primary lymphoedema.

What is Secondary Lymphoedema?

The majority of cases of lymphoedema happen as a result of some known cause which has damaged or blocked an otherwise normal lymphatic system. The swelling is said to be “secondary” to the damage caused to the lymphatics. So, what are some of these known causes of damage to the lymphatic system?

Secondary left arm lymphoedema
Secondary left arm lymphoedema
Secondary left leg lymphoedema
Secondary left leg lymphoedema
      • Secondary lymphoedema commonly results from the surgical removal of lymph nodes in the treatment of cancer. For example, the interruption to the lymph vessels caused by the removal of the lymph nodes from the armpit with breast cancer surgery, may lead to lymphoedema of the arm on the operated side.Â
      • If lymph nodes have been removed from the groin for a leg melanoma, then swelling may occur in that leg due to the decreased ability of the damaged lymph system to transport away the lymph fluid. However, many people who have had their lymph nodes removed will have other lymphatic vessels which will compensate and divert the fluid along other pathways to drain away. For others, the compensation is not enough and secondary lymphoedema will develop.Â
      • Radiotherapy directly to the lymph nodes may cause scarring and fibrosis of lymph vessels leading to swelling. For those that have both surgery and radiotherapy to the lymph nodes, there is a greater risk of lymphoedema occurring.Â
      Tumour cells, benign or malignant, may invade the lymphatic vessels or nodes, blocking them and impeding the lymph flow, causing lymphoedema.
      The lymphatic vessels and nodes can be damaged by infection. The inflamed and scarred lymphatic cannot perform their function to transport away the lymph fluid from the tissues and secondary lymphoedema occurs. Such infections may be caused by bacteria, virus, fungus or parasites.
      In certain tropical areas, worm parasites transmitted by mosquitoes, enter the lymphatic vessels, eventually causing them to block when the worms die, and leading to often severe lymphoedema, especially of the legs. Worldwide, in tropical countries such as India, Indonesia, Malaysia and Papua and New Guinea, filariasis is the most common cause of secondary lymphoedema.
      Surgery to strip varicose veins, or bypass grafts to the veins in the legs, can lead to damage of the lymphatic vessels that lie close to the veins.
      The fine lymphatic vessels that lie beneath the skin may be damaged from direct trauma to the body part, e.g. burns to the body; motor vehicle accidents that cause large grazes or open wounds.

Secondary Lymphoedema does not necessarily occur straight away after the initial damage to the lymphatic system, but sometimes develops months to years later. For this reason, be aware of your body and seek treatment if you notice swelling developing.
© Lymphomation, Summer 2004