Histological Assessment of the Effect Laser Irradiation on Full-Thickness Skin Wound Healing in Rabbits Models

Abstract

Since there is currently no ideal treatment, wound healing impairment is a significant clinical challenge that is the subject of ongoing research into effective wound healing strategies. As a result, it has been demonstrated that low level laser therapy (LLLT), which is used for wound healing, can effectively control both the local and the systemic response. This study was conducted on 24 adult, clinically healthy male rabbits for this purpose. On each animal's back, full-thickness excisional wounds measuring 2 cm x 2 cm were created following sterile skin preparation. The animals were randomly split into two equal groups, each with twelve rabbits. In the group that acts as a control; 5 milliliters of phosphate-buffered saline was used to treat wounds. In the group treated; for the first seven days, the wounds were only treated with (LLLT) at a rate of 5/5 second at 8j/cm2. At the seventh, fourteenth, and 35th days of healing, histopathological biopsies were performed. The control group's histopathology revealed hemorrhage with inflammatory cell infiltration, primarily neutrophils, and congested blood vessels in the gap seven days after surgery. Necrotized neutrophils, hemolysis, and granulation tissue under the dermis were present in the gap at fourteen days. Between the muscle fibers, there was hemolysis. At 35 days, there was irregular proliferation of fibrous connective tissue, and congested blood vessels with mononuclear cell infiltration could be seen in the gap. At seven days, the treated group has completely sloughed the epidermis and a thin crust on the skin's surface with a small incision. In the dermis, there is a lot of infiltration of inflammatory cells, mostly lymphocytes and macrophages. There is also a lot of granulation tissue and a lot of adipose tissue with a lot of thick collagen network. At fourteen days, the epidermis' epithelial layers have healed completely and a keratinized layer is present. In the dermis, a proliferating and thick collagen network, scattered inflammatory cells, and regular fibrosis with hemorrhage and the development of a new B.V. At day 35, look for narrow scar tissue with complete epithelization, a keratinized layer above the epidermis, new vascularization with a lot of regular fibrosis and few regular collagen, new hair follicles, new blood vessels, and scattered macrophages. We concluded that full-thickness wound healing is positively influenced by the use of low level laser therapy (LLLT), which creates a microenvironment favorable to cell growth and differentiation.