Current Applications and Indications of Allograft Adipose Matrix: A Systematic Review

BACKGROUND: Autologous fat transfer remains a staple in aesthetic and reconstructive surgery because of its regenerative capacity and tissue integration. However, limitations such as donor-site morbidity and unpredictable volume retention persist. Allograft adipose matrix (AAM), a product made from human fat tissue that serves as a natural scaffold to promote adipogenesis, offers a promising alternative, serving as a scaffold for adipogenesis and delivering key extracellular matrix components. This review examines clinical applications and outcomes in soft-tissue augmentation. METHODS: A systematic review was conducted by means of PubMed/MEDLINE/Cochrane/Embase using "allograft adipose matrix," "decellularized adipose matrix," "Renuva," and "Leneva." Studies published up to May 30, 2024, involving human or animal AAM treatment, were included. Data on demographics, clinical use, injection protocols, outcomes, volume retention, and complications were extracted and analyzed. RESULTS: From 352 studies, 10 involving humans and 9 involving animals were included. Human studies included 93 patients. Indications for AAM included foot and dorsal hand rejuvenation, abdominal and buttocks contouring, temple atrophy, breast and genitalia augmentation, pressure ulcers, and facial rejuvenation. AAM injection volumes varied, with retention rates ranging from 21.5% to 100%. The most common complications were erythema, swelling, injection-site pain, and burning, all resolving easily. Patient satisfaction scores ranged from 72.9% to 100%. CONCLUSIONS: AAM provides a promising biomaterial for soft-tissue augmentation. Histologic analysis supports its role in adipogenesis and neovascularization. Animal studies suggest enhancements through combination therapies, including AAM with autologous fat, platelet-rich plasma, or synthetic scaffolds. Further research is needed to optimize decellularization protocols and improve bioactivity and tissue incorporation.