Acellular Adipose Matrices Seem to Be an Effective and Safe Strategy for Soft Tissue Regeneration and Volume Restoration: A Systematic Review of Clinically Relevant Literature.

Significance: Autologous adipose tissue grafting (AAG) can provide soft tissue reconstruction in congenital defects, traumatic injuries, cancer care, or cosmetic procedures; over 94,000 AAG procedures are performed in the United States every year. Despite its effectiveness, the efficiency of AAG is limited by unpredictable adipocyte survival, impacting graft volume retention (26-83%). Recent Advances: Acellular adipose matrices (AAMs) have emerged as a potential alternative to AAG. AAMs include adipose tissue-derived extracellular matrix (ECM) and growth factors (GFs), but not cells. When grafted, AAMs serve as scaffolds with biochemical and biophysical cues for local cell (especially adipocytes) proliferation, regenerating soft tissue, and restoring volume. Being acellular, the AAM is not limited by adipocyte necrosis/apoptosis. Critical Issues: Research on AAM has mostly been conducted on small animal models and with small grafts. Clinically relevant AAM research (large animal models and/or clinical trials) is sparse and limited. To address this gap, we conducted a systematic review of clinically relevant AAM literature to assess AAM's clinical efficacy and safety. Across 11 human and 1 porcine study involving reconstructive or cosmetic procedures, we found that AAMs resulted in significant volume retention, adipogenesis, and angiogenesis, without notable adverse effects. Future Directions: Available quantitative and qualitative data suggest that AAM is an effective and safe alternative to AAG. Yet, the current literature is still limited; more robustly designed studies with standardized methods to assess outcomes will help validate these positive preliminary findings, and possibly pave the way for a broader clinical adoption of AAM.