Long-term volume retention after fat processing with cotton gauze rolling and centrifugation: A comparative study in nude mice

Abstract

Background: Autologous fat grafting for correcting soft-tissue defects in cosmetic and reconstructive procedures has grown in popularity. Fat processing is implicated as a variable affecting quality, viability, and subsequent graft retention. This study aimed to identify a better fat processing technique for optimal outcomes.

Methods: Fresh human aspirated fat was processed with cotton gauze rolling or centrifugation and named rolled fat (RF) and centrifuged fat (CF), respectively. Processed fat grafts were analyzed in vitro to determine yield, stromal vascular fraction (SVF) content, and viability. Then, RF and CF were transplanted subcutaneously to different flanks of every nude mouse. Fat samples were weighed to evaluate the volume retention 3 months post-transplantation. Tissue structure, densities of vessels, and CD68-positive macrophages were examined by histological staining.

Results: The compression rate of lipoaspirate by cotton gauze rolling was 25%, which was more effective than the rate of 50% by centrifugation. The numbers of SVF cells per gram of RF and CF were (1.02 ± 0.14) ×10⁶ and (0.65 ± 0.26)×10⁶, respectively (P < 0.05). Long-term graft retention was significantly higher in the RF group than in the CF group. Histological analysis of all implants revealed intact adipose tissue and equivalent vascularity. The number of CD68-positive macrophages in the RF group was much less than in the CF group on day 7.

Conclusion: The results of this animal experiment showed that, compared with centrifugation, processing with cotton gauze rolling produces more condensed fat, higher SVF content, and decreased inflammatory response, thereby improving long-term volume retention. Further explorations are required to verify the superiority of cotton gauze rolling in clinical settings.

Keywords: Autologous fat grafting; Centrifugation; Cotton gauze rolling; Fat processing; Volume retention.