Morphological study of rat skin flaps treated with subcutaneous dimethyl sulfoxide combined with hyperbaric oxygen therapy

Current Status of Experimental Animal Skin Flap Models: Ischemic Preconditioning and Molecular Factors

Skin flaps are necessary in plastic and reconstructive surgery for the removal of skin cancer, wounds, and ulcers. A skin flap is a portion of skin with its own blood supply that is partially separated from its original position and moved from one place to another. The use of skin flaps is often accompanied by cell necrosis or apoptosis due to ischemia-reperfusion (I/R) injury. Proinflammatory cytokines, such as nuclear factor kappa B (NF-κB), inhibitor of kappa B (IκB), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and oxygen free radicals are known causative agents of cell necrosis and apoptosis. To prevent I/R injury, many investigators have suggested the inhibition of proinflammatory cytokines, stem-cell therapies, and drug-based therapies. Ischemic preconditioning (IPC) is a strategy used to prevent I/R injury. IPC is an experimental technique that uses short-term repetition of occlusion and reperfusion to adapt the area to the loss of blood supply. IPC can prevent I/R injury by inhibiting proinflammatory cytokine activity. Various stem cell applications have been studied to facilitate flap survival and promote angiogenesis and vascularization in animal models. The possibility of constructing tissue engineered flaps has also been investigated. Although numerous animal studies have been published, clinical data with regard to IPC in flap reconstruction have never been reported. In this study, we present various experimental skin flap methods, IPC methods, and methods utilizing molecular factors associated with IPC.

Effects of oxidative stress and apoptosis on vascularity and viability of perforator flaps

We investigated lateral thoracic and posterior thigh perforator flaps for viability, vascularization, perfusion and apoptosis in a rat model. Wistar albino rats were divided into six groups: lateral thoracic artery perforator flap (LTPF) sham, 3 × 2 cm² LTPF, 3 × 6 cm² LTPF, posterior thigh perforator flap (PTPF) sham, 3 × 2 cm² PTPF, and 3 × 6 cm² PTPF. Flap viability was determined on postoperative days 1 and 7. On day 7, flaps were photographed and their viability was measured using two-dimensional planimeter paper. Tissue samples were harvested for examination by histology and immunohistochemistry. Viability differences were statistically significant. Epithelial thickness, vascularity and number of fibroblasts were reduced in the 3 × 6 cm² groups. Neovascularization and apoptosis based on molecular tests were not significantly different among groups. Flap size and location are important factors for closure of surgical or traumatic defects. We suggest that for clinical application, wound complications will occur less frequently with perforators that nourish large areas of flaps.