Significance: Chronic wounds can lead to poor outcomes for patients, with risks including amputation and death. In the United States, chronic wounds affect 2.5% of the population and cost up to $28 billion per year in primary healthcare costs.
Recent advances: Allograft tissues (dermal, amnion, and amnion/chorion) have shown efficacy in improving healing of chronic, recalcitrant wounds in human patients, as evidenced by multiple clinical trials. Their mechanisms of actions have been relatively understudied, until recently. Research in murine models has shown dermal allografts promote re-epithelialization, amnion allografts promote granulation tissue formation and angiogenesis, and amnion/chorion allografts support all stages of wound healing. These findings not only confirm effectiveness, but they shed light on mechanisms of action responsible for their therapeutic utility in patients.
Critical issues: Despite the promise of allografts in chronic wound care, a gap exists in understanding which allografts are most effective during each wound healing stage. The variable efficacy among each type of allograft suggests a mechanistic approach towards a proposed clinical treatment algorithm, based on wound characteristics and patient's needs, may be beneficial.
Future directions: Recent advances in allografts provide a framework for further investigations on how allograft selection can be based on specific needs of individual patients. This requires additional research to identify which allografts support the best outcomes during each stage of the wound healing process as well as utility in specific wound types. Longitudinal human studies investigating the long-term impacts of allografts, particularly in the remodeling phase, are also essential to developing a deeper understanding of their role in sustained wound repair and recovery.