Fat is Magic. Part II.

Last month we talked about fat and how it has redeemed itself in recent years, at least in certain swathes of the scientific and medical communities.  Not pure evil, not a shape to be judged, but fat simply as a starting point, infinite possibility contained within golden-hued pebbles.  In the special realm of cleanrooms and laboratories, fat was magic: filling up voids and smoothing out crevices, transforming radiation-damaged tissue and removing the patina of age from skin, bearing those truly mystical stem cells.

In the relatively recent past, new acquaintances at cocktail parties and bars and weddings would consistently stumble through the same half-serious conversation upon learning that I was a plastic surgeon.  It would start off with an open armed gesture, hands hovering over one body part (tummy, hips, thighs) before quickly moving to wild gesticulations around a different region (breasts, butt), while inquiring, "if we could only move a little from here to over there," before finally dissolving into nervous giggles.

I don’t get that kind of ribbing at social events anymore.  Wistful wishing has become a plastic surgical reality: fat transfer (also known as fat grafting) has become a thing.  Think of it as an “auto-transplant” of your own fat from someplace you would rather not have it to someplace where you could use a little more oomph.

Now let’s dive into the technical details for all my fellow nerds and geeks out there (for the slightly squeamish in the audience, feel free to scroll down a few paragraphs, past the photos, to the close).  There are three basic steps to any fat transfer surgery: harvest, purification, and placement.

Fat Harvest

Harvest of the fat is performed via surgical liposuction.  This begins with that renowned surgical instrument, the Sharpie marker.  Many surgeons like to use an assortment of colors to draw on the patient’s skin to outline both the areas to remove fat as well as the areas to stay away from, and in the case of fat transfer, where that fat graft will eventually go.  After their markings, many patients look like a toddler ran amuck in the art room on their bodies, but these markings are a critical topographic map for guiding the liposuction/fat harvest.

Next, some form of anesthesia is given to make the patient comfortable.  If it is a very small amount of fat to be moved, it might only be a local anesthetic (like the numbing medication a dentist injects before taking care of a cavity).  For a more extensive transfer, a combination of a local injection with some oral or IV pain/sedation medications, or a full general anesthetic can be used. 

Once you are comfortable (or asleep), your surgeon looks at all the areas previously marked for “donation”.  A few access points are made for the liposuction procedure.  These are pretty small - about ½ inch in length - and the goal is to hide them in cosmetically favorable areas like natural skin creases and places where underwear will cover them.

Usually a small amount of fluid, called tumescent solution, is infused into the targeted areas.  Tumescent is simply sterile salt water, with at least two critical additives: lidocaine (for local pain control) and epinephrine (to reduce the amount of blood loss).  Once this has soaked into the tissues, procurement of the fat with liposuction can begin, using long thin perforated metal tubes called cannulas to mechanically remove the fat under the skin with vacuum suction. 

IV Fluids waiting to become tumescent (Photo Credit; Dr. Lim)

Cannulas (Photo Source: www.microaire.com)

If you have ever watched a video online of surgical liposuction, you’ll notice two things: it’s a very mechanical process, and it’s probably not amongst any plastic surgeon’s most elegant moments.  But liposuction is very effective - you can precisely target a small area of unwanted fullness with a tiny cannula, or you can perform large volume liposuction that can dramatically alter a patient’s shape.  Either way, by mechanically (and strategically) removing fat and relying on the skin’s inherent contractility, liposuction alone can transform areas of fullness into a more pleasing contour.

But we’re still talking about fat transfer here, and the second step is processing the fat. 

Fat Purification

Everything in the harvest process is sterile - the tubing deposits the fat into a clean container, and from there surgeons have options for how they prefer to purify the fat.  Some surgeons literally use sterilized kitchen equipment: cheesecloth and/or strainers.  Others use proprietary self-contained systems for harvest and transfer. 

Kitchen Strainer (Photo Source: Www.amazon.com)

Freshly spun fat in the centrifuge (Photo Credit: Dr. Lim)

In my practice, we have found good success with technology somewhere in between; we do traditional tumescent liposuction into sterile vacu-containers that decant some of the excess fluid that separates naturally through gravity.  Once the fat has been separated, we then sterilely spin the fat in a centrifuge to purify the cells even further, so that what remains is essentially “liquid gold”.

Fat Injection

The last step is a marriage of both the art and science of plastic surgery - carefully injecting aliquots of purified fat into the targeted space, to remold and reshape in three dimensions. 

Fat graft, ready for transfer (Photo Credit: Dr. Lim)

It is not simply squirting fat indiscriminately as if you are filling up a water balloon.  The transfer must be done accurately and precisely, taking into account the underlying anatomy, the quality of the tissue and skin, and the patient’s particular goals for the procedure.  For fat transfer to be successful, we need each individual fat cell to find a happy new home in the tissue you’re putting it within - this is the concept of “auto-transplantation” at the cellular level.  Too little fat transferred, and you will not get the results you are looking for; too crowded, and the fat will not “take root” and can literally melt away.

But if the time is taken to craft a surgical plan with the utmost care - and follow the three steps of thoughtfully harvesting, gently processing, and precisely placing the fat graft by layering and building a few cells at a time - really lovely transformations are possible that are simply you.

~~~

Check back next month to learn more about the transformative possibilities that fat can create (a truly natural breast enhancement, a more shapely booty), in the final installment of this short series: Fat is magic.

References,
1. Khouri RK Jr and Khouri RK. Current clinical applications of fat grafting. Plastic & Reconstructive Surgery. Sept 2017. 140(3): 466e–486e
2. Zielins ER et al. Autologous fat grafting: the science behind the surgery.  Aesthetic Surgery Journal. April 2016. 36(4): 488–496.

By Dr. Angeline Lim of Duet Plastic Surgery - Expert Plastic Surgeons

Angeline Lim, M.D. and Jennifer Weintraub, M.D. are the board-certified plastic surgeons of Duet Plastic Surgery, a boutique-style practice in Palo Alto, California.  When not guiding her patients through their health and beauty journeys in the operating room, Dr. Lim is still trying to find a way to wring just a few more minutes out of every day.