Making Your Fat Work for You
A recent plastic surgery trend, known as fat grafting, is to use a person’s own fat to augment different areas of their body. Although fat grafting has recently gained popularity, it is not a new method. Published reports on fat grafting date back to the 1960's, and textbooks were dedicated to the topic in the 1980's. Over the next 20 years, fat grafting gained increasing popularity with plastic surgeons through development of techniques such as the Brazilian butt lift. This type of butt lift involves strategically injecting large volumes of fat into the gluteal region to create a larger and rounder bottom. These days, fat grafting has become common place in most plastic surgery practices and has spread to other specialties such as orthopedic surgery. In this post, I'll go over how the fat is prepared.
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| Fat from liposuction is captured in the glass bottle so it may be retained and processed for grafting |
The fat is first obtained through liposuction. I previously discussed the process of liposuction in more detail in my blog post on liposuction. However, when the fat will be used for fat grafting rather than thrown away, a few variations are made to help enhance survival of the fat when placed in a new location. Some surgeons will not add lidocaine to the initial tumescent fluid and just use the combination of saline and epinephrine. Depending on where the fat will be injected, different size cannulae may be used. If the face will be injected, the surgeon will utilize a smaller cannula to have finer aliquots of fat compared with the buttocks, where large amounts of fat are injected.
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| Processing fat - getting from the bowl of fat to the right to the syringes on the left |
Once collected, the fat must be separated from the oils and fluids collected with it. This is known as processing the fat. The best method to process the fat is still up for debate, with numerous research projects dedicated to the topic. The main focus of the research is to determine what type of processing best helps the fat survive. The research also investigates how to extract the stem cells, known as adipose-derived stem cells (ASC). ASC provide an added benefit of revitalizing the surrounding tissue they are injected in. This property of ASC has really expanded the field of fat grafting.
There are several ways to process fat. The most basic is to let gravity do the work. The aspirate is allowed to sit in the canister until the fat and fluid separate (like when you let salad dressing sit). These two canisters on the right show how drastic this separation can be after only 10 minutes. The picture on the left is the initial appearance once liposuction is complete. Separation can already be seen occurring during the time it took for the all the liposuction to be performed. After 10 minutes, three layers are visible in the second picture. The red layer is the mix of blood and tumescent fluid. The top two layers are composed of varying densities of adipose cells and other cell types such as stem cells. This method is not frequently used except in large volume fat grafting. For small volumes, gravity with the help of Williams-Sonoma can produce a washed aspirate. The tools of the trade can be seen in the image to the right. The fat is poured over the strainer and irrigation fluid is mixed in with the spoon. Unwanted parts of the aspirate drip into the bucket and the fat is retained in the strainer.
The next step is referred to as "rolling" the fat over a filter, in most cases TELFA dressing. The TELFA has a nonstick surface with gauze sandwiched between. As seen to the right, the aspirate is poured over the TELFA then gently rolled back and forth over the dressing with occasional squirts of saline to clean the fat. Once the fat has reached the consistency of custard it is ready for injection. This method is typically used for small volume fat injections in areas such as the face or joints, as it can be very time consuming to process. Similar to this method but for larger volumes, Allergan has a device named the REVOLVE system. It entails a closed system with a propeller. The fat enters the chamber and is flooded with irrigation. The propeller then washes the fat against a fine mesh that acts as the filter. Large quantities of fat can be rapidly processed this way. We use this system for many of our breast reconstruction cases.
Centrifugation is the final method that I'll cover in this post. As the name suggests, a centrifuge is the center of this technique. The aspirate is loaded into syringes and spun in the centrifuge for several minutes. Once the cycle is complete, the aspirate will have separated into multiple layers. As with the first technique, the bottom layer is the blood and tumescent fluid followed by varying densities of fat cells and other cells. At the top is a layer of oil from the fat cells bursting during liposuction. In the image below the oily layer can be seen at the top of the syringes. The bottom red layer and top oily layer are removed prior to injection. The remaining portions are high-quality fat ready for injection. This technique is employed for both small and large volumes. For faster processing, larger syringes up to 60 mL (2 shot glasses) can be used. This is the volume of syringes shown in the image.
Once the fat has been processed, it is ready for injection. The applications of fat grafting widespread. The volume increase is only limited by the amount of fat that can fit within the area (as one of my bosses always said "you can't fit 10lbs of potatoes in a 5lb sack"). Aesthetically, it can be used to augment the buttocks as in a Brazilian butt lift or create larger breasts. When injected in the face it can help reverse the signs of aging or be used as a permanent filler. Recently, fat grafting has been shown to improve joint function in arthritic joints. In our burn unit, we use fat grafting to help restore tissue pliability and volume. As you can tell there are a multitude of uses for fat grafting, which go well beyond those stated here. So the next time you get mad at your fat, just visit your plastic surgeon and ask how they can make your fat work for you.
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| The final product - liquid gold |
