PATEY PRIZE 2 O8 NOT PRESENTING – moved to HPB Session O9 COMPARATIVE ANALYSIS OF REEPITHELIALISATION IN PARTIAL THICKNESS BURN AND EXCISIONAL WOUNDS OF SIMILAR DEPTH

Introduction: Re-epithelialisation of cutaneous wounds is a complex multistep process. In partial thickness wounds, keratinocytes from wound edges and the remnants of the epidermal appendages contribute to the process. We investigated whether the mechanism of injury had any influence on reepithelialisation of partial thickness wounds in a porcine model. Method: Partial thickness wounds were created on the back of anaesthetized Hampshire pigs using either a thermo-regulated block (burn) or a dermatome (excisional). Wounds and unwounded skin were harvested at 7, 14, 29, 44, 57 and 70 days post-wounding and processed for routine histology. Neoepidermal thickness, length and number of hair follicles in the dermis were measured. Data were analysed using non-parametric tests with a significant p value of <0.05. Result: Re-epithelialisation was significantly faster in excisional wounds compared to burn wounds at day 7 post-wounding (81% versus 22% of the wound length). The number of hair follicles in the underlying dermis of excisional wounds was high at day 7 but interestingly, by day 14, it had increased by 1.5 times in burn wounds compared to excisional wounds. Neoepidermal thickness was similar in both wounds at day 7. However on day 70 post-injury, neoepidermis of burn wound was significantly thicker than that of excisional wound and the number of hair follicles was similar. Conclusion: Re-epithelialisation of a wound is influenced by the nature of injury. This study provides evidence for managing burn and donor site wounds effectively. Importantly it emphasises the need for testing novel dressings based on mechanism of injury.