Mechanical Supplementation with the Stromal Vascular Fraction Yields Improved Volume Retention in Facial Lipotransfer: A 1-Year Comparative Study

Abstract

Background: Unpredictable volume maintenance in the long term is a major limitation of autologous fat grafting. Objectives: The authors compared results of autologous lipotransfer to the face with or without enrichment of fat with the stromal vascular fraction (SVF). Methods: Thirty patients with asymmetric depletion of facial volume were included in a prospective study. Patients were randomly assigned to undergo a single session of autologous fat transfer with washed adipose tissue (control group) or with washed adipose tissue combined with the pellet of centrifuged lipoaspirate, which contained the SVF (enriched group). Patients were evaluated clinically and from photographs. A subset of 5 patients in each group underwent computed tomography (CT) preoperatively and 12-months postoperatively for quantitative assessment of graft retention. Washed and fractionated lipoaspirates were evaluated histochemically and with flow cytometry to determine relative abundances of viable cells. Results: No major complications occurred. CT findings 12 months postoperatively indicated that patients who received SVF-enriched fat had significantly better volume retention (9.6% volume loss vs 24% in the control group; P = 0.013). Independent surgeons more frequently rated long-term aesthetic outcomes as excellent for patients in the enriched group (82.5% vs 47.6% for control group). Laboratory results indicated that each pellet contained approximately 16,000 intact adipose-derived stem cells. Conclusions: Lipotransfer with SVF-enriched adipose tissue is safe and associated with improved volume retention, compared with transplantation of unenriched fat. The SVF can be dissociated from lipoaspirate by centrifugation to yield a large quantity of viable regenerative cells, without enzymatic digestion.