Fat Grafting and Reshaping: How it Works


Beth Longware Duff, Medical Editor

Beth Longware Duff is an experienced writer and reporter whose work on a wide variety of topics has been published in numerous newspapers and magazines. Her health and medical writing credits include nationally distributed videos for the March of Dimes Birth Defects Foundation, and she is the recipient of numerous awards including an American Cancer Society Media Award and a New England Press Association Award for Health Reporting. She holds a degree in Communications from Ithaca College.

August 12 2008

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Fat as Filler: the Natural Solution?

What could make more sense than moving fat from one spot on the body where there's too much to another spot where there's too little? That's a highly-simplified description of fat grafting.

This relatively straightforward procedure is an autologous donation (meaning it comes from your own body), so the chance of rejection is nil. The fat is soft, feels natural, and is readily available. If you're having liposuction, one of  the top surgical cosmetic procedures in 2007 in the United States, you can use its byproduct to aesthetically enhance almost any part of your body.

The procedure goes by a number of different names: fat transfer, fat autographs, autologous fat transplantation, fat injecting, and microlipoinjections. While the concept was introduced in 1893 by a German physician who used a small piece of upper arm fat to build up a patient's cheek, it wasn't until almost a century later that the development of liposuction made harvesting the fat cells much easier.

Today a surgeon performs the graft by removing fat from the patient's donor site with a liposuction cannula or a syringe equipped with a large bore needle. The next step varies, depending on the surgeon's preference.

"The simplest way is to then just squirt it right where you want it," says Karol Gutowski, MD, board-certified plastic surgeon and a member of the American Society of Plastic Surgeons' Fat Grafting Task Force. "Or you can condense and purify it by letting it stand in the syringe so that it layers out, just as happens with oil and water. Another option is to pour it over sterile cheesecloth and filter it so the liquid and oils pass through and the fat cells stay on top. Or you can put it in a centrifuge and within a minute or two it separates and you can take the fat layer off." The fat is then ready to be reinjected into the patient's body.

The best donor sites are the lower stomach, inner thighs, and inner knees. Treatment sites are more numerous. Facial fat grafting and reshaping is one popular option and includes filling nasolabial folds, tear troughs, wrinkles, creases, and depressed scars. It can be used to rejuvenate the face without a face lift, or to fill in areas of the face that have lost volume with age. Other possibilities include enhancing lips, under-eye fat grafting, augmenting cheeks, fat grafting buttocks, and smoothing and repairing aged hands.

"I also use it to correct deformities caused by liposuction," says Dr. Gutowski, an Associate Professor of Surgery at University of Wisconsin. "I see patients with irregularities and defects from that and I've been treating them with multiple injections of fat taken from their buttocks or elsewhere."

One of the key issues with fat grafting is the survivability of the fat cells after they are removed, treated, and returned to the body. Several factors affect the overall outcome, such as how the fat cells are harvested, the technique used to treat and return them to the body, where they are deposited, how muscular that site is and how much it moves, and whether or not any disease is present.

There are potential risks and side effects associated with fat transfer, including infection, bleeding, hematoma (a pool of blood that forms under the skin), seroma (a pocket of fluid under the skin), fat migration within the body, the opening of a surgical wound, and nerve damage. The body reabsorbs between 20% and 95% of the transferred fat, depending on the injector and the technique used. The surgeon must over inject to allow for reabsorption, so the treated area may look overly plump or swollen for a week or so. Bruising, redness and swelling are common at both the donor and injection sites. Fat injections last anywhere from 6 months to 8 years.

Fat grafting costs more than commercial fillers like Juvederm or Restylane, and is less convenient. "Patients want instant gratification. They want to see the results and they want to get back on with life. The off-the-shelf products offer that," says Dr. Gutowski. "The way fat grafting is right now, it's not quite able to fulfill that need." 

There is one application of fat grafting that remains controversial, and that is breast augmentation. The American Society for Aesthetic Plastic Surgery (ASAPS) and the American Society of Plastic Surgeons (ASPS) issued a joint statement in early 2007 that they do not recommend the practice.

"Although there has been some research on the safety and efficacy of this procedure, more research is needed before concluding that the procedure's benefits outweigh the risks," the professional organizations cautioned. "Despite increasing consumer interest in this technique, there is little clinical evidence to suggest that fat grafting for breast augmentation is safer or better than saline or silicone implants, and long-term complications, including tissue scarring and calcification, can obscure or mimic breast cancer during breast cancer screening by self examination, mammography, ultrasound, or magnetic resonance imaging." ASAPS notes that as little as 7 to 14 ounces of fat – the amount required for an average enlargement – injected into the breast can result in these complications.