24. Improving Re-epithelization after Burn Injuries: The Role of Pixel-grafting and Wet Wound Healing

PURPOSE: Complex facial and extremity burns present a difficult challenge affecting skin contour, mobility, and appearance. Management requires consideration not only to the skin, but to a patient’s quality of life. Interventions often require stage-reconstruction, revision for increasingly unsatisfactory results and a burdensome dressing during healing. This standard is costly, limited by donor-site availability, and often morbid. Currently, there are no single-stage interventions with simple dressings to address complex, full thickness burns. Our team has formerly shown the advantage of adipose-first reconstruction. Here we aim to provide a complete approach by demonstrating the efficacy of single-staged minced skin grafting plus adipose in an incubator-like microenvironment with a platform wound device (PWD) to achieve rapid reconstruction after burns. METHODS: A customized burn device was used to induce sixteen standardized full-thickness burns on Female Yorkshire swine. Delayed escharectomies were performed to the level of fascia. One group received standard of care skin grafting with either bolster or PWD. In another group, autologous split-thickness skin was cut into pixel size (0.3x0.3 mm) grafts, combined with or without adipose, and followed by application of either bolster or PWD. Wounds were followed for 4-weeks with weekly photography, ultrasound, histology, and tension measurements. RESULTS: The PWDs provided an optimized environment and protected the wounds from graft displacement despite no limitations in mobility. As early as one week, epithelialization started in the pixel with PWD group with visible epithelioid islands on the wound bed granulation tissue. This progressed with a similar trend throughout the 4-week period eventually leading to near-complete epithelization and keratinization. Immunofluorescence staining demonstrated reconstruction of trilaminar cutaneous architecture and viability of adipose. Distinct differences in contour were noted between the bolster and PWD groups. CONCLUSION: In both the bolstered and moist PWD-environment, pixel-grafts survived to form a viable basal layer. Use of positive-pressure (bolster) vs. negative-pressure PWD demonstrated distinct differences in the convexity/concavity and topography of the single-stage skin graft with critical implications for aesthetic reconstruction. Additionally, minced grafting minimized donor burden and alleviated the need for graft orientation. This study demonstrates the efficacy of a single-staged approach and the use of a sustainable dressing that both provides enhanced reconstruction and decreased burden.