Volume Replacement with Fat Transfer

Contemporary cosmetic surgeries rely as much on conventional lifting and repositioning as volume replacement. Here is what you need to know about autologous fat transfer.

What is autologous fat transfer?

Autologous fat graft, or fat transfer, is the action of transferring fat cells from a place where there are many (hips, tights, belly) to a place where they are not enough, so as to give it a desired volume or to fill it up. Think of the distension of the cheeks, deflation of the breasts, the stigmata of aging hands or face, for example. In such a procedure, we talk of an autologous fat graft, since it is the cells of your body that are used instead of fillers or implants. The result is natural, longer lasting and readily accepted by the body since the cells are the patient’s. Autologous fat grafts are perfectly biocompatible with the donor, they are a better and longer-lasting option than artificial fillers, but they cost more.

Are some donor areas best indicated and receiver areas contraindicated?

In the case of autologous fat grafts, let us start by saying fat is fat. Your body will not discriminate depending on the origin of the fat, whether is it coming from the outer tights, the abdomen or the buttocks.

What is important to the surgeon is that the donor area is safe for the procedure, has more than enough and that it is easy to access. The autogenous fat will not “migrate” back to where it was harvested, this an urban legend. Fat cells, however, are alive. They are being nourished by blood flow, and some are expected to die after the procedure, because the healing process takes time. Those cells that are gone do not get replaced, fat cells do not multiply or get replaced. They simply change volume, following your body mass index. In weight gain the fat cell increases in size, whereas in weight loss they diminish in volume.

Injections into highly animated facial (such as lips), or poorly vascularized regions (body areas with poor blood supply), are not indicated in the case of fat grafts.

What does a fat transfer procedure look like?

A fat graft procedure is done in three steps:

1. The harvesting,

2. The purification and preparation,

3. The deposition (also called placement).

Your surgeon will examine you and decide of a donor area. A good surgeon is conservative about the amount of fat to be harvested from the donor area and will not overharvest it. We saw earlier how it is expected to lose some fat cells (it might not be a problem for some of us), but what are we looking at, exactly? Under best circumstances, and with the best technique, it is expected to lose about 30% of the grafted fat cells.

The harvesting

Success and viability of fat begins with its collection. Fat cells to be harvested are regrouped in clumps of lobules, under the skin, above the muscles. After anesthesia, short incisions have been made at the site of choice. The surgeon inserts a sterile blunt-tipped harvester cannula of a specific diameter and side bores (holes), to access these lobules. These needles are specifically designed to keep the fat cells in the best shape possible and are connected to syringes in which the fat can be transported. Once the cannula is placed in the proper position under the skin, the suction effect can be activated. A good surgeon will always make sure of that, so that the skin does not get damaged.

The speed and negative pressure at which the fat pads are being sucked out and the purification process here are some of the factors to the survival rate. A great surgeon knows this and will be careful not to be greedy nor in a hurry! For this very reason, it is very important that they might be harvested with utmost care, and it is also the reason why you might need an additional lighter fat transfer later on to ensure a fully satisfying result.

The purification and preparation

Once the fat cells have been harvested, always in small amounts (usually 10 ml per extraction site), they are carried away in syringes. The harvest is placed in a centrifuge to spin the fat, through a sieve or some other method. This process is to remove unwanted tissue parts, such as neurovascular structures, fatty acids, lymphatics, and residues from the injection that come with the fat pads, and would interfere with the success of the graft “take”. Once the fat cells have been hence processed, they are transferred in other small syringes that will be used in the fat grafting.

The fat transfer and placement

Survival of grafted fat is the mark of a great surgeon. Fat graft survival rate relies on the harvest of the cells, excellent purification, healthy microvascular blood flow and a layered fashion placement, to ensure volume uniformity.

Once the receiving area has been prepared, the injection sites and entry point decided and anesthetized, the surgeon will insert a blunt-tipped cannula connected to a small fat-filled syringed, right under the skin of the area needing to be beefed-up. The incision sites allow for multidirectional access to specific sites (the cannula might be directed to various angles from the point of entry). Fat grafts are always placed as the cannula is being withdrawn, to eliminate the risk of lumps and other complications. The fat lines are placed as a grid, over multiple layers of tissue planes.

A good surgeon will avoid the overfilling of the subcutaneous plane (right under the skin) as this might lead to lumpiness, graft resorption, and asymmetry. It is always safer to underdo it and come back a bit later if a revision is needed than to overfill.

The addition of platelet-rich-plasma (PRP) increases the survivability of the grafted fat. PRP contains growth factors that will bind to the fat cells and promote the growth of new blood vessels that will ensure their nourishment and therefore, their survival.