Background: Lymphedema is a chronic peripheral swelling caused by a dysfunction of the lymphatic system, leading to discomfort and loss of upper limb movement. Therapies to treat or manage this swelling have limited evidence, partly because of a paucity in objective lymphatic measures. This study explored the role of near-infrared (NIR) imaging in evaluating interventions.
Methods: Nine healthy volunteers underwent NIR fluoroscopy using a microdose (50 μL, 0.05% w/v) of indocyanine green to quantify lymphatic behavior before and after a 15-minute period of manual lymph drainage followed by compression garment (CG) therapy for a 10-minute period. Images were taken at the forearm and elbow after each intervention. Lymphatic function was defined by the number, size, displacement, and speed of lymph packets. The lymph parameters were analyzed to assess the effects of the interventions compared with basal values.
Results: Baseline (BL) parameters of lymph function revealed high variability in the number, size, and speed of packets between individuals. Despite this variance, both interventions showed statistically significant improvement (p < 0.05) in displacement and speed at the forearm compared with BL. The velocity of transient lymph packets increased from a median of 6.7 mm/s at BL to 13.3 mm/s after manual lymphatic drainage (MLD) and 10.5 mm/s after CG.
Conclusion: Lymphatic activity increased significantly after MLD, with relative increases being maintained after a short time period of CG application. NIR fluoroscopy has the potential to both monitor lymph pathology and provide robust parameters in the assessment of interventions.
Keywords: compression garment; fluorescence imaging; lymphatic system; lymphedema; manual lymphatic drainage.