Inflammatory lymphedema
Bilateral lower extremity inflammatory lymphedema (BLEIL) is a distinct type of lymphedema occurring in a setting of acute and prolonged standing, such as in new recruits during basic training. The possible underlying mechanisms are thought to be venous congestion and inflammatory vasculitis. Physiology
Lymph is formed from the fluid that filters out of the blood circulation and contains proteins, cellular debris, bacteria, etc. The collection of this fluid is carried out by the initial lymph collectors that are blind-ended endothelial-lined vessels with fenestrated openings that allow fluids and particles as large as cells to enter. Once inside the lumen of the lymphatic vessels, the fluid is guided along increasingly larger vessels, first with rudimentary valves to prevent backflow, which later develops into complete valves similar to the venous valve. Once the lymph enters the fully valved lymphatic vessels, it is pumped by a rhythmic peristaltic-like action by smooth muscle cells within the lymphatic vessel walls. This peristaltic action is the primary driving force, moving lymph within its vessel walls. The regulation of the frequency and power of contraction is regulated by the sympathetic nervous system. Lymph movement can be influenced by the pressure of nearby muscle contraction, arterial pulse pressure and the vacuum created in the chest cavity during respiration, but these passive forces contribute only a minor percentage of lymph transport. The fluids collected are pumped into continually larger vessels and through lymph nodes, which remove debris and police the fluid for dangerous microbes.
Imaging modalities have been suggested as useful adjuncts to the ISL staging to clarify the diagnosis. The lymphedema expert Dr. Ming-Huei Cheng developed a Chengs Lymphedema Grading tool to assess the severity of extremity lymphedema based on objective limb measurements and providing appropriate options for management. I. Grading
Grade 1: Spontaneously reversible on elevation. Mostly pitting edema. Grade 2: Non-spontaneously reversible on elevation. Mostly non-pitting edema. Grade 3: Gross increase in volume and circumference of Grade 2 lymphedema, with eight stages of severity given below based on clinical assessments. II. Staging
As described by the Fifth WHO Expert Committee on Filariasis, and endorsed by the American Society of Lymphology., the staging system helps to identify the severity of lymphedema. With the assistance of medical imaging apparatus, such as MRI or CT, staging can be established by the physician, and therapeutic or medical interventions may be applied:
Stage 0: The lymphatic vessels have sustained some damage that is not yet apparent. Transport capacity is sufficient for the amount of lymph being removed. Lymphedema is not present. Stage 1 : Swelling increases during the day and disappears overnight as the patient lies flat in bed. Tissue is still at the pitting stage: when pressed by the fingertips, the affected area indents and reverses with elevation. Usually, upon waking in the morning, the limb or affected area is normal or almost normal in size. Treatment is not necessarily required at this point. Stage 2: Swelling is not reversible overnight, and does not disappear without proper management.