Exercise-Enhanced Indocyanine Green Lymphography Protocol: A Fast and Reliable Method of Diagnosing Lymphedema

Abstract

BACKGROUND: Indocyanine green (ICG) lymphography is an advanced imaging tool that can visualize superficial lymph flow and has been a vital part of lymphedema diagnosis, management, and tracking in patients with lymphedema. The goal of this prospective study was to determine the effect of exercise on the time it takes ICG dye to show full lymphedema disease pattern during ICG lymphography, with the intent to create a standardized and accelerated ICG lymphography protocol in patients with lymphedema. METHODS: Nine patients (10 arms, 13 legs) with unilateral and bilateral lymphedema exercised on a recumbent cross trainer for five minute intervals at a rated perceived exertion of 11–13. ICG lymphography scans were performed before exercise, after each 5-minute exercise interval to identify plateau time, and then every hour after the initial scan for 6 hours. A postintervention survey was provided to the patient assessing their opinion of exercise on the process. RESULTS: The ICG dye plateaued after 3 cycles of exercise (15 minutes of exercise in total) in all limbs studied, and the dye was shown to start receding after 4 hours. Patients preferred exercising to speed up ICG studies compared with the traditional method, which involves waiting between 6 and 24 hours between initial and delayed ICG lymphography scans. CONCLUSIONS: Exercise can accelerate lymph flow, with disease pattern plateauing at 15 minutes of exercise in patients with lymphedema. From this we know that exercise allows for more efficient and standardized ICG lymphography studies.