小児虚血性耳介皮弁修復のためのエクソソーム探索

Avulsions of the upper third of the ear often present with skin flaps of compromised vascularity. Although initially viable, these flaps may later develop ischemic changes ranging from epidermolysis to full-thickness necrosis, delaying healing. Angiogenesis, primarily mediated by vascular endothelial growth factor (VEGF), is essential for tissue repair. In children, VEGF promotes endothelial cell migration and proliferation, accelerating wound healing. Currently, VEFG is the primary target of therapeutic angiogenesis approaches, and microRNAs have emerged as key angiogenic regulators. Exosomes have gained relevance in regenerative medicine as paracrine mediators of skin repair. VEGF expression peaks between days 3 and 7 after injury; hypothetically, this VEGF window is considered optimal for delivering proangiogenic exosome cargo directly to the ischemic skin flap. By providing microRNA-mediated proangiogenic signals early in the healing process, exosomes may enhance tissue perfusion and improve flap survival. We report the case of a 10-year-old girl with a partial soft-tissue degloving injury of the upper third of the auricle. The avulsed flap had folded onto itself, causing venous congestion. After repositioning, flap distal congestion persisted and progressed to partial tissue necrosis by postoperative day 3. The wound was treated with Rosa damascena stem cell-derived exosomes, resulting in complete skin regeneration, evident by day 14. This case demonstrated the safe clinical use of Rosa damascena stem cell-derived exosomes in a pediatric posttraumatic ischemic auricular flap, suggesting their potential as a therapeutic option for flap salvage in children. Larger controlled studies are required to confirm efficacy and establish treatment protocols.