Introduction
A wide variation in fat grafting outcomes has been reported in the literature with processing methods including centrifugation and Telfa™-rolling having been advocated without direct comparison of their differing efficacy. Adipose tissue has a complex cellular composition; thus we hypothesize that various processing techniques yield different processed lipoaspirate samples with distinct cellular profiles that impact fat graft survival.
Methods
Lipoaspirate harvested from human subjects undergoing elective liposuction was used in this study. Three types of processing techniques were compared. Fresh lipoaspirate was either centrifuged at 300 x g for 3 minutes (CPL), rolled twice on Telfa™ gauze (TPL), or unprocessed (UPL). Following centrifugation, the blood and tumescent fraction was drained, the oil was decanted and wicked, and the resulting processed lipoaspirate was used as our CPL group. Fluorescent-activated cells sorting (FACS) was used to quantify and characterize progenitor cell populations within each sample. A glycerol-3-phosphate dehydrogenase (G3PDH) assay was used to determine the number of functional adipocytes. Additionally, 1.5mL of CPL, TPL or UPL was grafted into the dorsal subcutaneous tissue of wild type FVB mice and harvested at 2 weeks to assess fat graft survival and vascular endothelial growth factor (VEGF) secretion by ELISA assay.
Results
Progenitor cell number (x102) per gram of TPL (22.39) was greater than that in CPL (16.1) or UPL (9.35). However, CPL contained a significantly greater percentage of pre-adipocytes than UPL (62.1% vs. 6.1%, p<0.05) as well as a greater number of functional adipocytes (0.260 units/ml) than TPL (0.238 units/ml) and UPL (0.235 units/ml) (all p<0.05). Two weeks following fat grafting TPL had a greater percentage of fat graft survival (99.3%±0.1 vs. 83.7%±1.3 vs. 57.6%±5.0, p<0.05) and a greater VEGF secretion (148.9±12 vs. 107.4±7 vs. 43.1±7pg/ml, p<0.05) than CPL and UPL, respectively.
Conclusion
Lipoaspirate processing techniques have a significant impact on short-term fat graft survival rates. We demonstrate that progenitor cell number and VEGF secretion directly correlates with fat graft survival. Our results suggest that Telfa™-rolling may be the ideal processing technique for fat graft survival.