Indocyanine green velocity: lymph transportation capacity deterioration with progression of lymphedema.

Lymph transportation capacity is a critical function maintaining fluid circulation. After pelvic cancer treatments, lymph obstruction at the pelvic region leads to abnormal lymph circulation, resulting in lymph pump dysfunction. Besides lymph circulation, lymph pump function is important for lymphedema evaluation. We assessed and analyzed lymph transportation capacity of secondary lower extremity lymphedema patients using indocyanine green (ICG) lymphography according to corresponding severity stage. Indocyanine green velocity and transit time could evaluate lymph pump function; ICG velocity decreases and transit time increases as the lymphedema severity stage progresses. Measurement of ICG velocity required 5 minutes after the dye injection, whereas that of transit time took more than 1 hour in severe cases. Indocyanine green velocity can be easily obtained and is recommended for evaluation of lymph pump function compared with transit time. Dynamic ICG lymphography, which evaluates both lymph pump function and circulation, plays an important role in comprehensive assessment of lymphedema pathophysiology.