Assessment of Hard-To-Heal Lower Leg Wounds With Near-Infrared Fluorescent Imaging: A Pilot Cohort Study

This case series explores the application of Near-infrared fluorescent (NIRF) imaging as a diagnostic tool for assessing hard-to-heal wounds. Our aim was to explore the potential of this modality to provide insights into wound perfusion, tissue viability and healing progress. We conducted a 12-week non-randomised observational study, a subset of an ongoing interventional study. Participants with hard-to-heal lower limb wounds received multi-disciplinary wound care. NIRF imaging using Indocyanine green contrast was performed prior to treatment, at six and 12 weeks. Visual assessment and quantitative analysis of fluorescent intensity within a region of interest were summarised. Seventeen participants were included, with a mean (SD) age of 64 (9) years. Forty-seven percent were diabetic and 45% had peripheral arterial disease. Wound size changes ranged from 23% to -95%. Changes in wound healing in patients whose intensity reduced had better observed effects (i.e., reduction in area and increase in granulation). Increasing intensity was observed in three patients requiring further treatment for pathology not visually observable. NIRF imaging allows visualisation of revascularisation and wound healing progress prior to observable changes in hard-to-heal wounds, providing insight into inflammation that may otherwise go unnoticed. Further research is needed to determine the utility of NIRF in wound management.