Comparative Evaluation of the Efficacy of Injection and Topical Application of Adipose-Derived Stromal Vascular Fraction in Autodermoplasty with a 1:6 Mesh Expansion Ratio

Background: Treatment of patients with extensive deep burns remains a challenge in combustiology. The limited availability of donor sites necessitates the use of highly expanded meshed skin grafts (1:6 expansion ratio), but their engraftment is associated with a high risk of complications. The application of autologous stromal vascular fraction (SVF) derived from adipose tissue is a promising approach. Objective: To perform a comparative evaluation of the efficacy of injection and topical application of SVF in autodermoplasty with split-thickness skin grafts using a 1:6 mesh expansion ratio in patients with deep skin burns. Materials and methods: The study included patients with deep third-degree burns admitted to the Department of Thermal Injuries of the St. Petersburg I.I. Dzhanelidze Research Institute of Emergency Medicine between 2022 and 2025 who underwent split-thickness skin grafting with a 1:6 mesh expansion ratio. Patients were divided into three groups: a control group (n=30), an SVF injection group (n=31), and an SVF topical application group (n=31). Treatment efficacy was assessed using clinical, planimetric, cytological, immunohistochemical methods, and laser Doppler flowmetry. Results: The use of SVF significantly improved the surgical outcomes. SVF injection reduced the time to complete skin autograft engraftment by 51% (from 17.0±2.7 to 8.3±1.8 days) and decreased the complication rate from 45% to 15%. Topical application of SVF reduced the time to complete graft engraftment by 43% (to 9.7±1.4 days) and lowered the complication rate to 15%. Cytological analysis demonstrated that both methods reduced neutrophil counts and increased fibroblast levels on day 3. At the same time point, immunohistochemical analysis revealed a 3-fold decrease in CD45+ cell expression (inflammation). In the topical application group, laser Doppler flowmetry demonstrated a 2.1-fold increase in microcirculation. Conclusion: The use of SVF in autodermoplasty with a 1:6 mesh expansion ratio significantly improves skin grafting outcomes. The injection method demonstrates superior performance in terms of engraftment speed, while the topical application method is more effective in stimulating microcirculation and is less invasive.