BACKGROUND: In the last decade, controversy has arisen regarding the influence of fat harvesting, processing and injection techniques on adipose tissue graft. The aim of this study is to compare the influence of three widely used fat processing techniques in plastic surgery on the viability and number of adipocytes and mesenchymal stem cells (MSCs) of aspirated fat. METHODS: A prospective cross-sectional study was conducted in 20 adult healthy female patients in whom material obtained by liposuction of the lower abdomen was separated and processed by decantation, washing or centrifugation. The morphology and quantity of adipocytes were determined by histological analysis. The viability and number of MSCs in the middle layer of each lipoaspirate and the pellet derived from centrifuged samples were obtained by multi-colour flow cytometry. RESULTS: Cell count per high-powered field of intact nucleated adipocytes was significantly greater in decanted lipoaspirates, whereas centrifuged samples showed a greater majority of altered adipocytes. MSC concentration was significantly higher in washed lipoaspirates compared to decanted and centrifuged samples. However, the pellet collected at the bottom of the centrifuged samples showed the highest concentration of MSCs. CONCLUSION: Based on the theory of cell survival stating the importance of adipocytes' integrity for graft survival and the theory claiming the importance of regenerative MSCs in the maintenance and stabilisation of fat transplant, washing may turn out to be the best processing technique for adipose tissue graft take. While eliminating most contaminants during the process, it preserved and maintained the quantity, integrity and viability of the most important components of aspirated adipose tissue. Copyright 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
BACKGROUND: In the last decade, controversy has arisen regarding the influence of fat harvesting, processing and injection techniques on adipose tissue graft. The aim of this study is to compare the influence of three widely used fat processing techniques in plastic surgery on the viability and number of adipocytes and mesenchymal stem cells (MSCs) of aspirated fat. METHODS: A prospective cross-sectional study was conducted in 20 adult healthy female patients in whom material obtained by liposuction of the lower abdomen was separated and processed by decantation, washing or centrifugation. The morphology and quantity of adipocytes were determined by histological analysis. The viability and number of MSCs in the middle layer of each lipoaspirate and the pellet derived from centrifuged samples were obtained by multi-colour flow cytometry. RESULTS: Cell count per high-powered field of intact nucleated adipocytes was significantly greater in decanted lipoaspirates, whereas centrifuged samples showed a greater majority of altered adipocytes. MSC concentration was significantly higher in washed lipoaspirates compared to decanted and centrifuged samples. However, the pellet collected at the bottom of the centrifuged samples showed the highest concentration of MSCs. CONCLUSION: Based on the theory of cell survival stating the importance of adipocytes' integrity for graft survival and the theory claiming the importance of regenerative MSCs in the maintenance and stabilisation of fat transplant, washing may turn out to be the best processing technique for adipose tissue graft take. While eliminating most contaminants during the process, it preserved and maintained the quantity, integrity and viability of the most important components of aspirated adipose tissue. Copyright 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.