RESUMO
BACKGROUND: Because of their easy accessibility and versatile biological properties, mesenchymal stem cells taken from fatty tissue (adipose-derived stem cells, ADSC) are attractive for various potential clinical uses. For example, ADSC can be added to fatty tissue before transplantation in the hope of improving the outcome of autologous lipotransfer: the modified procedure is called cell-assisted lipotransfer. The clinical use and commercial promotion of this novel stem-cell treatment (and others) are spreading rapidly, even though there is not yet any clear clinical evidence for its safety and efficacy. METHODS: In cooperation with the German Cochrane Center, we systematically searched the literature according to the PRISMA criteria. Eight major medical databases were searched. The retrieved publications were examined by two independent reviewers and assessed using objective criteria. RESULTS: After screening of the 3161 retrieved publications by title, abstract, and (where appropriate) full text, 78 were still considered relevant. 13 of these were reports of clinical studies; only 3 of the 13 met criteria for grade II or III evidence. The studies that were analyzed involved a total of 286 cell-assisted lipotransfer procedures with a longest follow-up time of 42 months. Oncological safety was not demonstrated. CONCLUSION: The studies published to date have not shown that cell-assisted lipotransfer is generally superior to conventional autologous lipotransfer. They dealt with safety aspects inappropriately or not at all. The case of cell-assisted lipotransfer illustrates the indispensability of high-quality clinical evidence before the introduction of novel stem-cell-based treatments.