Where the fat comes from
If we have not said it out loud, most of us have thought of how nice it would be to take fat from one place in our body and move it to another (In men, this is more often wished about hair!). Fat is unappealing when it is in some places but attractive when it is in others. Plastic surgeons, much like patients asked themselves the question: Since we have liposuction and dermal fillers, why can’t we just move fat from the undesirable areas to the chosen locations. The answer, it turns out, is autologous fat transfer (fat injections).
The word autologous simply means that instead of taking tissue from a donor, tissue is taken from the person themselves. Perhaps you have heard of the term autologous skin graft. Essentially the fat is removed through liposuction, cleaned, purified and injected into another place in the body. Of course the actual fat injection process is a more complicated than that, but the result is mostly as advertised: fat is redistributed from where you do not want it to where you do want it.
Fat injection procedure
The liposuction that is used to harvest fat cells for fat injections is a little different than traditional liposuction. One major difference is that the fat needs to be taken out with as little damage as possible. In a traditional liposuction since the fat is destined to be medical waste, the goal is to simply remove fat artfully and efficiently. This means essentially liquefying the fat and removing it out under vacuum. In the case of fat injection, the liposuction is far gentler because the goal is to remove fat in relatively large sections or chunks.
The carefully harvested fat needs to be purified before it can be put back in the body. Since the liposuction is done using the tumescent technique, the saline that was used to fill the space under the skin needs to be mostly removed. Also any blood or fibrous, non-fat tissue must be separated. The purified fat is then carefully injected into the desired location. Unlike some dermal fillers, injected fat cannot be shaped and molded very easily. Therefore the fat injection needs to be done with exceptional care to avoid lumpiness.
Most often, surgeons will harvest the fat for fat injections from areas that yield “high quality” fat and from places where the patient would not mind losing some fat. Since fat injections are predominantly performed on women, a common liposuction site is the inner thigh (a trouble area for most women). It is also common to take fat from around the navel (belly button).
Results
On a small scale, fat injections can be used to plump the lips or to fill in lines and creases of the face. Instead of using a synthetic dermal filler to correct wrinkles, the patient’s own fat can do the job. On a larger scale, fat injections have been used for breast augmentation. Another reasonably common site for autologous fat transfer is in the hands. As we age, the skin of the hands thins and the fat under the skin is lost. Fat injections can reverse this process to a degree.
Fat injections are not for everyone. The procedure tends to be a bit more expensive than other dermal fillers, but you have to consider that a liposuction procedure is included. Further, when fat is being transferred to a large area, such as the breasts, there is more chance for unevenness and lumpiness from the injected fat as it presses up underneath the skin. You should discuss outcomes and alternatives with your cosmetic plastic surgeon before having a fat injection.