Long-Term Volumetric Retention of Autologous Fat Grafting Processed With Closed-Membrane Filtration

Background: Some practitioners have criticized the unpredictable retention associated with autologous fat transfer. Potential causes of variations in predictability include intrinsic (patient-related) or extrinsic factors, such as harvesting, processing, and graft-delivery technique. Objectives: The authors sought to determine the long-term retention of autologous fat graft processed with a closed-membrane filtration system, to compare this retention with centrifuge-processed fat, and to analyze factors that affect graft retention. Methods: This was a prospective analysis of 26 female patients (representing 52 hemi-midfaces) who underwent autologous fat transfer to the midface via the closed-membrane filtration system. The Vec-tra 3D camera and software were employed for all photography, which was then analyzed to compare immediate preoperative images with long-term follow-up images (obtained at least 10 months postprocedure). The authors compared the findings with data from their previous study of centrifuge-processed fat grafts (historical controls). Results: Mean values were as follows: age, 55 years; follow-up period, 17 months; amount of autologous fat injected, 8.88 mL; absolute volume augmentation measured at the last postoperative visit, 3.71 mL; and retention, 41.2%. Results of Welch's ttest, in which the membrane-filtration data were compared with the previous centrifuge data (31.8% long-term retention), showed a significant difference (P =.03). Retention in this study was significantly higher in patients younger than 55 years (53.0% vs 31% for older patients; P =.001) and lower in patients who underwent rhytidectomy (23.8% vs 47.6% for nonrhytidectomy patients; P<.001). Conclusions: Autologous fat processed by closed-membrane filtration had a significantly higher long-term retention rate than did centrifuged-processed fat injected by the same surgeons.