The lymphatic system is composed of collecting vessels and lymph nodes.

The lymphatic system of the lower extremities includes a superficial and a deep system divided by the muscle fasciaaponeurosis. Perforating lymphatic vessels interconnect both systems.

The superficial system includes the interfascial and epifascial subsystems, where the latter is the most superficial one, located between the skin and the saphenous fascia (FIG 1).

Lymphedema can be primary, occurring as a structural or anatomical birth defect in which genetics seem to play a major role. Secondary lymphedema may occur after surgery and/or radiotherapy, trauma, infection, and other causes. Lymphatic filariasis following infection of invading pathogens is globally the most common cause of secondary lymphedema.¹

The transport capacity of lymphatic drainage may be reduced by damage that further affects the homeostasis of the interstitium, including both the cellular and extracellular compartments.

Lymphostasis with fluid accumulation in the tissues leads to inflammation and subsequent tissue remodeling of skin and subcutaneous tissues with fibrosis and fat deposition.

Untreated lymphedema tends to deteriorate with time, leading to fibrosis and fat deposition that occur at later stages. Inflammatory changes make the patient susceptible to recurrent episodes of erysipelas and cellulitis.

Initially, there is a phase with reduced transport capacity without clinical swelling.

Stage 1 lymphedema includes pitting edema that subsides with limb elevation, whereas elevation is not effective in stage 2, when fibrosis of the tissues may already be seen.

Stage 3 includes increasing volume of the extremity with congestive dermatitis, trophic skin, and fat deposition.²

A pitting test shall be performed with pressure applied to the affected area (ideally over the tibial bone) for at least 60 seconds with the examiners fingers. The absence of pitting confirms tissue remodeling and fat deposition, where lymphaticovenular anastomoses may be less successful and suction-assisted lipectomy shall be considered.³

Imaging methods for lymphedema include radionuclide lymphoscintigraphy, indocyanine green (ICG) lymphography, and magnetic resonance lymphangiography.

Lymphoscintigraphy can indicate the location of lymph collectors, but does not provide information about specific areas of occlusion.²

ICG lymphography, on the other hand, visualizes real-time superficial lymph flow without radiation exposure.⁴

ICG lymphographic patterns are categorized from normal linear pattern (stage 0) to abnormal dermal backflow patterns; splash (stage I), stardust (stages II-IV), and diffuse stardust (stage V) patterns with lymphedema progression of the lower extremity⁵ (FIG 2).

Decongestive physiotherapy and compression garments have been the most common nonsurgical treatment methods in reducing edema volumes, although they are not curative.