|
 Dr. Sherman |
Dr. Sherman, a private practitioner specializing in cosmetic, facial plastic and reconstructive surgery at Del Mar Cosmetic Medical Center, Del Mar, Calif., provides a rationale for developing standardized methods for AFG analysis by outlining the various factors that potentially can affect AFG quality and longevity and evaluating these variables within the laboratory setting utilizing such a standard AFG assay.
"Multiple variables in AFG technique can contribute to the disparate results that have been reported for long-term graft retention. Those differences, together with variability between studies in the methods used for evaluating the biological parameters of fat grafts, confounds our ability to make inter-study comparisons of outcomes," says Dr. Sherman, who is also associate clinical professor of surgery, University of California, San Diego.
"Implementation of a core set of analytical tools in combination with a common understanding of fat-graft anatomy and physiology should allow us to identify approaches that can yield the best clinical results. It would allow valid, scientific comparisons of how specific variables — including new fat-harvesting technologies and tissue-processing techniques — affect AFG safety and efficacy," Dr. Sherman says. "The standardized assay can also be implemented in research aimed at understanding how new technologies affect adipose regenerative cell safety and efficacy. Looking farther ahead, it may enable research to discover new biomarkers for identifying patients who would more likely benefit from fat grafts enhanced with stem cells processed from additional harvested fat."VARIABLES IN OUTCOMES Differences in donor characteristics as well as in methods for tissue acquisition, processing and delivery may all affect the AFG characteristics and the results of the fat-transfer procedure.
For example, variables in fat harvesting that may affect graft characteristics include the size and style of the cannula, wetting-solution composition, degree of suction and type of mechanical force/energy used (ultrasound-, water- or power-assisted).
Similarly, graft characteristics may potentially be affected by the differing processing techniques, such as sedimentation, washing, centrifugation and straining. Use of different cannula types, variations in volume placed per stroke and site of AFG deposition are other variables in graft delivery that may influence the outcome.
"Currently, there is only anecdotal evidence about the relative effects of different methods of fat harvesting, processing and delivery on AFG outcomes, but no real scientific data, and so we don't know if certain techniques are best. Nor do we know whether fat can be adequately cryopreserved," Dr. Sherman says.
