The Impact of Re-Defining Wound Healing on Wound Management and Wound Recurrence

Introduction: Industry definition of complete wound closure is a wound that has achieved “re-epithelization without drainage or dressing requirements confirmed at two consecutive study visits separated by two weeks”. Despite this definition of wound closure as a primary clinical and study end-point in wound care, standardization in use of this definition is lacking1. The most common definition used in clinical studies, from 2010 to 2019, remains the date when a wound is determined to have achieved 100% re-epithelization2 on visual inspection1,3. The primary concern with this definition is the date of 100% reepithelization may only signify wound coverage and not complete healing1. Discontinuation of protective wound coverings, active offloading, and/or compression may result in recurrence as the wound is not truly healed. Utilizing NIRS we have re-defined wound healing as wound bed oxygen saturation matching surrounding tissue.Methods:Serial imaging assessment with a point-of-care, non-contact, near infrared imaging device (SnapshotNIR, Kent Imaging Inc., Calgary, AB, Canada) was performed to assess site specific wound tissue oxygenation and relative perfusion. Imaging assessment was performed during the course of wound healing and followed the date the wound was determined to be 100% re-epithelized on visual inspection until tissue oxygen saturation levels at the wound site were homogeneous to the patient’s baseline tissue oxygenation levels.Results:Fifteen patients underwent serial imaging of their wounds. The average difference in time between wound re-epithelization based on visual inspection versus return to patient baseline tissue oxygenation level at the wound site on near-infrared imaging was 13.5 ± 10 days (median: 12 days; range: 0 to 35).Discussion: Near infrared imaging provided an objective assessment of complete wound healing at an average of two weeks following the date a wound was determined to be re-epithelized on visual inspection. This coincides with industry guidance on the definition of complete wound healing. However, some patients in this study took up to 5 weeks to demonstrate a healed wound on near infrared imaging. (Figure 1) These findings suggest the benefit of incorporating near infrared imaging to guide wound management referencing the optimal time to transition from protective wound dressings and active offloading to full activity. This is contrary to the current accepted definition and should be done to minimize the risk of wound recurrence because of premature discontinuation of active offloading or compression.References:1. FDA Wound Healing Clinical Focus Group. Guidance for industry: chronic cutaneous ulcer and burn wounds-developing products for treatment. Wound Repair Regen 2001;9(4):258-68. 2. Gould L, Li WW. Defining complete wound closure: closing the gap in clinical trials and practice. Wound Repair Regen 2019;27(3):201-24. 3. Snyder D, Sullivan N, Margolis D, Schoelles K. Skin Substitutes for Treating Chronic Wounds. Rockville (MD): Agency for Healthcare Research and Quality (US); February 2, 2020. https://www.ncbi.nlm.nih.gov/books/NBK554220/. Last accessed January 9, 2024.