A Comprehensive In Vitro Comparison of Preparation Techniques for Fat Grafting.

BACKGROUND: Lipomodelling is a technique that uses patient's own fat for tissue regeneration and augmentation. The extent of regenerative effect is reported to be determined by the numbers of adipose tissue-derived stem cells (ASCs) and the viability of cells in processed adipose tissue, which, together with other factors, influence the degree of graft retention. This study addresses whether differences exist in properties of fat graft obtained by three commonly used techniques.

METHODS: Adipose tissue harvested from the hypo-gastric regions of 14 patients was processed by decantation, centrifugation, and membrane-based tissue filtration. Morphology of each preparation was assessed by electron microscopy and overall cell viability by live/dead assay. Number of ASCs was determined and their stem cell character was assessed by the presence of cell surface molecules (CD105, CD90, CD31, CD45) and by their capacity to differentiate into adipogenic and osteogenic lineages.

RESULTS: First, morphologies of processed fat samples obtained by individual procedures differed, but no preparation caused obvious damage to cellular and acellular components. Second, although highest numbers of ASCs were contained in upper fraction of centrifuged lipoaspirates, the difference between preparations was marginal. Third, maximal concentration of adipose fraction (removal of watery component) of lipoaspirate was achieved by membrane-based tissue filtration. Finally, no significant differences in overall viability were detected.

CONCLUSIONS: Properties of processed lipoaspirate were influenced by the preparation procedure. However, the differences were not dramatic; both centrifugation and membrane-based filtration are methods of choice whose selection depends on other criteria, such as practicality for individual surgical settings.