Site Specific Evaluation of Lymphatic Vessel Sclerosis in Lower Limb Lymphedema Patients

Background: Histological changes in the collecting lymphatics in patients with lymphedema are classified as Normal type, Ectasis type, Contraction type, and Sclerosis type (NECST) classification. In this study, we investigated the condition of the lymphatic vessels in different sites of the legs. Patients and Methods: We prospectively investigated the lymphatic vessels of patients with lymphedema who underwent lymphaticovenous anastomosis (LVA) from August 8, 2014 to August 4, 2015 based on the NECST classification. Lymphedema was diagnosed using lymphoscintigraphy, indocyanine green (ICG) lymphography, and the International Society of Lymphology (ISL) Classification. The affected limbs were divided into four sites: proximal thigh (Site 1), distal thigh (Site 2), proximal crus (Site 3), and distal crus (Site 4). Results: A total of 109 patients (205 limbs and 1028 lymphatics) were included in this study. Of the 109 patients, there were 100 women and 9 men with an average age of 61 years. The ratio of Ectasis type vessels increased toward the distal end of the limb with the highest occurrence rate being 54% at Site 4. As ISL stage, ICG stage, and lymphoscintigraphy stage advanced, so too did the ratio of Sclerosis type. In secondary lymphedema patients with lymphedema, the ratio of Ectasis type was more predominant in the distal end of the limb, whereas this tendency was not observed in primary lymphedema patients. Conclusions: Sclerotic lymphatics are more predominantly found in the proximal limb whereas nonsclerotic vessels are more often found toward the distal end. These findings help lymphatic surgeon determine incision sites.