The Impact of the Wound Shape on Wound Healing Dynamics: Is it Time to Revisit Wound Healing Measures?

Introduction: Wound healing is a multifaceted process, which can be impacted by many endogenous (e.g., compromised immune system, limited blood supply) or exogenous (e.g., dressing, presence of infection) factors. An essential step in wound management is to track wound healing progress. It typically includes tracking the wound size (length, width, and area). The wound area is the most often used indicator in wound management. In particular, wound closure is the single parameter used by the FDA to measure wound therapeutics' efficiency. Here, we present some arguments on why the wound area alone is insufficient to predict wound healing progress. Methods: We have developed an analytical approach to characterize an epithelization process based on the wound's area and perimeter. Results: We have obtained the explicit results for wound healing trajectory for several wound shapes: round (2D), elongated cut (1D), and rectangular. The results can be extended to complex shapes. Conclusions: From geometrical considerations, the wound healing time is determined by the shortest dimension (the width) of the wound. However, within that time, the wound healing trajectory can be different. Our calculations show that the shape of the wound may have significant implications on a wound healing trajectory. For example, in the middle of the wound healing process (t/T=0.5), the 1D wound model predicts 50% closure, while the 2D model predicts 75% closure (25% remaining). These considerations can be helpful while analyzing clinical data or designing clinical or pre-clinical experiments.