Ask the Doctor: How Do Fat Transfers Work?

Fat TransfersPatients often ask “How do fat transfers work, and do they last?” It is a very good question, and pertinent, too, because fat transfers have become very common in cosmetic surgery over the past several years. Fat transfers have assumed an important role in facial rejuvenation, breast augmentation surgery, buttock enhancement, and the secondary treatment of body contouring deformities, so it is important to understand what is going on.

Fat transfer is a lot like the old real estate saying: It’s all about location, location, location. Most of us have extra fat in areas we don’t want, and the beauty of the fat transfer is that we can remove some of this unwanted fat and relocate it to where we want to enhance volume. Even though this concept is quite simple, the actual way the procedure is performed has taken cosmetic surgeons many years to develop. We are still constantly improving and enhancing our techniques as we get a better understanding of how these techniques affect the survival of the fat in the new location.

The first step in fat transfer is to collect the fat from the donor site. The most common location where we harvest fat is the tummy, but we can use many potential sites, including the love handles, the thighs, and the back of the arms. The fat is collected by liposuction, either using a syringe system or a system with a fat collection chamber. The fluid obtained during liposuction (the aspirate) is then treated to remove excess fluid from damaged fat cells so that concentrated fat is ready to inject. There is significant variability in how surgeons prepare the fat for transplantation. This prepatory step can be as simple as gently straining the aspirate, may involve washing the fat, or may involve centrifuging the aspirate. The prepared fat is then loaded into syringes for injection.

The injection of the fat cells into its new “home” is done using fat grafting cannulas, these are generally small and designed to be gentle on the fat cells. The surgeon injects the fat into many tunnels and layers, as you want the fat to be widely dispersed in the tissues and not to “pool” in one area. Pooling leads to a decreased “take” of the transplanted fat. To explain this further, I like to use the analogy of planting seeds. Like seeds, the fat grafts need to get nutrients from the bed in which they are planted in order to survive. If you plant a full bag of seeds into a single hole in the ground, the seeds in the middle of the “pool” would not be able to get their roots into the dirt and would eventually die. That’s how it works with transplanted fat – if you put too much in one place, the cells in the middle will die and will be absorbed by the body.

When fat cells survive in their new location, they are there forever, and will be of stable size (unless you gain or loose a lot of weight). Cosmetic surgeons love to argue sometimes about the best way to harvest, prepare, and transplant the fat in order to optimize graft survival, and although we’ve made tremendous progress (fat transplantation is now highly effective and reliable – probably in the range of 70% survival), I don’t think we know all the answers yet. Be cautious if you feel you are being sold a “magic solution” for fat grafting, as these are often not backed up by good clinical evidence, at least currently.

One more word of warning relates to “stem cell fat grafts.” Stem cells are a current hot topic in medicine, and indeed stem cell science has tremendous potential to change the way medicine will be in the future. All tissues – including fat harvested for transfer – have stem cells anyway. However there is currently no compelling science to support the clinical claims of any special stem cell fat transplantation techniques in aesthetic surgery, and there is a lot of deceptive advertising to entice unknowing patients. In fact, both the American Society for Aesthetic Surgery and the American Society of Plastic Surgeons have issued a joint statement emphasizing this point.

The physicians at the Emory Aesthetic Center keep up with the latest developments in fat transplantation, and we’d be happy to help you figure out how they can work for you.


About Dr. Eaves

Felmont Eaves, MDDr. Eaves recently returned to Atlanta, Georgia, to head the Emory Aesthetic Center as Medical Director, having previously completed his plastic surgery residency as well as a fellowship in endoscopic and minimally invasive plastic surgery at Emory University, The Emory Clinic, and associated hospitals. Before joining the Emory Aesthetic Center, Dr. Eaves was a partner in Charlotte Plastic Surgery for more than fifteen years and served as group president from 2010-2012.

His professional and institutional committee memberships and offices include an impressive list of national, international and local plastic surgery organizations, societies, boards, task forces, advisory councils, coalitions and foundations, including having served as President of the American Society for Aesthetic Plastic Surgery (ASAPS) from 2010-2011 and Trustee (2011-Present).

Dr. Eaves’ primary areas of academic inquiry have been in minimally-invasive and endoscopic aesthetic surgery, patient safety, system and process improvement in plastic surgery, evidence-based medicine applied to plastic surgery and recontouring surgery after massive weight loss. He has received several patents for new medical devices he developed, and has made major clinical service contributions to his field. Dr. Eaves has published more than 100 articles, book chapters and book reviews on plastic surgery in peer reviewed publications, as well as manuals, videos, computer programs and other teaching aids and has coauthored the first textbook on the topic of endoscopic plastic surgery.

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