The Impact of Liposuction Technique, Centrifugation and Freezing in Adipose Tissue Viability

Introduction: The ideal technique for obtaining, processing and storage aspirated adipose tissue to be used as a graft is controversial in the literature. Due to the variety of methods for collecting and processing available, combined with the lack of a standardized measurement tool that allows us to compare diferent techniques.

Objectives: The main goal of this study was to evaluate the viability of aspirated adipose tissue and stem cells density, using variations in aspiration technique. The secondary endpoints were to evaluate viability after centrifugation and frozen at -20 ° C without cryopreservatives agents.

Methods: 10 female patients between 18 and 55 years were included. Adipose tissue was obtained by central pressure or syringe and 3 different types of cannula (1.8 mm Coleman, Mercedes 3 and 4 mm). 5 samples were centrifuged at 1200G x 3 min and 2 samples were frozen for a period of 1 to 3 months.

Tissue viability was assessed by XTT assay quantifying  mitochondrial activity and by conventional histology.

Stem cell density was assessed by enzymatic digestion with collagenase, culture for 7 days and counting on a Neubauer chamber.

Results: The highest viability was obtained through the 4 mm cannula versus a smaller diameter cannulas in XTT and histological assessment (0.61 vs 0.34 p = 0.04, 3.2 vs 2.. 42 p = 0.0073 respectively). The highest density of progenitor cells was also obtained with the 4 mm cannula (4.1 x 104 cells / ml vs. 1.3 x104 cells / ml, p = 0.041). There was no statistically significant difference between the use of central suction o syringes. After centrifuging the samples obtained with the 4 mm cannula, there is an improvement in the viability evaluated by XTT (0.54 vs. 0.7 p = 0.018). No cell activity was found after freeze samples using this methodology.

Conclusion: The use of a larger diameter canulla provides more tissue viability, regardless using syringe or central suction. It would be recommended to use centrifugation with proposed parameters. This study does not provide evidence for adipose tissue freezing in commercial refrigerator without cryopreservatives agents.