Fat grafting—with or without plastic surgery—improves appearance almost anywhere on the body

Over the past 10 years, the popu­lar­ity of fat grafting has increased substantially, but this is not a new surgical technique—it began as early as 1893 with free fat autografts that were used to fill soft-tissue defects.

Throughout the 20th century, physicians used fat grafts to correct many conditions, including hemifacial atrophy and other soft-tissue defects. Because of recent advances in technique to improve graft “take,” along with growing media attention, fat grafting is more popular that ever.

Before 1984, physicians used excised fat, minced into very small pieces, for grafts. That year, Gerard Illouz, MD, first used liposuction aspirate for autogenous fat grafts. Techniques have been refined, and now the fat to be used for grafting is carefully removed with a syringe and is processed minimally with a centrifuge to concentrate it. The fat is then grafted in thin strands, and a lattice is constructed to correct a wrinkle or restore volume to a specific area.

As a result of the success of modern fat grafting, its application has broadened to include lip augmentation, facial rhytids, facial-volume restoration, soft-tissue scarring, soft-tissue defects from injury or disease, liposuction defects, and many other new and original procedures and treatment areas. Fat-handling techniques have improved, but multiple or staged procedures are still the norm. Despite the possibility of requiring retreatment, fat grafting compares well to other soft-tissue fillers.

Early soft-tissue fillers included silicone, collagen, hyaluronic acid products, calcium hydroxyapatite, cyanoacrylate, and autogenous fibroblasts, and they all had benefits and risks. Many new substances for soft-tissue augmentation are in the pipeline, but each has some side effect or disadvantage. Substances that do not react well with tissues have limited effectiveness and wear off in months. Substances that last longer tend to have more problems with lumping, hardness, and foreign-body reactions like granulomas. A product that uses autogenous fibroblasts for augmentation is still awaiting approval from the Food and Drug Administration. It is natural, and it appears to be long-lasting.

The ideal soft-tissue-augmentation material is inexpensive and durable, feels natural, and has a low risk of adverse reactions. Autologous fat grafts meet these requirements. The procedure can be performed on an outpatient basis with local anesthesia, or can be combined with other plastic surgery procedures that are performed under general anesthesia.

Preoperative consul­tation and evaluation are important to identify the areas to be treated. The procedure, preoperative and postoperative care, expectations, and possible ad­verse reactions should be carefully reviewed and discussed with the patient. Patients must be educated about the effects of weight gain on their grafts. It is easier to perform secondary grafting than to remove fat grafts injected into normal tissues. Photographic documentation is important for planning and follow-up.

Fat Physiology

Fat is well-vascularized tissue with high metabolic activity, and it serves as an “energy reservoir.” The number of fat cells in an individual is generally assumed to be stable after the completion of adolescent growth. Changes in the volume of fatty tissue are correlated with the size of the fat cell and its overall lipid content. Fat cells that are removed for fat grafting do not regenerate, and harvest sites are generally reduced to some degree. The grafted cells shrink and enlarge with overall weight gain and loss, and they generally act as they did before they are grafted.

Fat cells reside in a connective network of supporting tissue. They have very thin membranes, and they store lipids and triglycerides. Fat harvesting should preserve as much structural integrity as possible. Many fat-harvest sites have been advocated: In general, harvest sites should be readily accessible, symmetrically located, and in areas where there is as little scar and fibrous tissue as possible. When the fat is difficult to remove, the fat cells’ structural integrity may be damaged, and graft “take” may be reduced. Variables that affect the success of the graft include

• removal technique;

• fat handling after removal;

• centrifuge speed and time;

• reimplantation procedures;

• recipient site vascularity;

• recipient site choice;

• patient aftercare; and

• the patient’s general health, metabolism, and smoking habits.

We believe that the best harvests are performed with a small syringe and a blunt-tipped cannula, so as to cause minimal trauma at a site where fat cells can be re­moved easily. If the fat does not come out readily, it is better to move to another area. Fat handling should be simple and atraumatic. We advocate leaving the sample in the syringe, centrifuging it, and using it for grafting with little or no transfer. Reimplantation should be done carefully and quickly. Multiple passes, from deep to superficial, with cross-tunneling, generally provide the smoothest results.

Patients with conditions such as diabetes and vascular disease, and smokers, are at risk for poor “take.” The success of the technique varies widely with the recipient site. For example, vascularity around the mouth is excellent, but graft “take” appears to be poor because this is a highly mobile area.

Contraindications include disease processes that adversely affect wound healing or cause infection. Breast fat grafting is generally contraindicated because it may lead to the formation of palpable nodules and microcalcifications that can mimic breast cancer in a mammogram. No specific laboratory tests or imaging studies are necessary for patients in advance of fat grafts.

Technical Considerations

Fat grafting consists of fat harvesting, fat-graft processing, and fat-graft placement. The most important aspect of the procedure is the atraumatic handling of the fat.

Before the procedure, the patient must be carefully marked to outline the defects and the harvest sites. The areas are anesthetized locally with a long spinal needle. Generally, we use a 22-gauge or 25-gauge needle. The tumescent fluid consists of 1 mg of epinephrine, 50 mg of lidocaine, and 500 mL of normal saline. Lidocaine doses of up to 35 mg/kg can be used, but fat harvesting usually requires a substantially smaller dose.

Approximately 5 minutes following infiltration, the fat can be harvested. Suction by hand with a 3- to 10-mL syringe and gentle aspiration motion preserves fat cells to the extent possible. Reducing the negative pressure and trauma will enhance fat-cell viability. Increasing the suction from –0.5 to –0.95 atmospheres has resulted in cell-membrane breakage and vaporization of fat cells, reducing their viability. Once harvesting is complete, the aspirate is kept in its original syringe and placed in a centrifuge. The aspirate separates into three layers: free oil on the top, the fat cell layer in the middle, and blood and serum on the bottom. Vigorous washing or straining may damage the fragile cells and affect the viability of the graft. After centrifuging, the fat can be reinjected.

Fat should be placed in the most vascularized layer of an area for maximum graft “take.” Grafting large amounts of fat may reduce “take” because neovascularization is reduced. Creating small tracts so that the fat graft is close to a fresh host vessel may improve “take.” Grafting from the deepest to the most superficial layer usually gives the best results.

A blunt-tipped cannula is used for graft injection to avoid damaging blood vessels. It is inserted into the donor site and pushed forward to create a tunnel. Withdrawing the cannula while gently distributing the fat in the canal is a process called “threading.” Another pass with the cannula is made into a fresh channel, and the process is repeated many times. Layering of the filled tunnels from deep to superficial is easier and prevents the formation of irregularities.

Overcorrection is important, because there may be residual liquid within the graft and because it is likely that some fat necrosis may occur. We recommend 20%–40% overcorrection. Some physicians advocate a two-procedure or three-procedure augmentation strategy that has proven successful in many cases. Injections may be repeated at 3-month intervals. Complications include resorption, unevenness, distortion, infection, undergrafting, and overgrafting.

Clinical Cases

We have used our fat-grafting methods to treat a wide range of conditions, both stand-alone and in conjunction with plastic surgery.

Case 1: Calf en­hance­ment. A female with narrow, thin calves desired more shapely legs (Figure 1, page 32). Calf implants must be placed through large incisions in the popliteal area and would likely leave visible scars, so we chose fat grafting. Also, in our experience, implants sometimes appear as too defined when a patient has a soft figure.

During surgery, 120 mL of centrifuged fat was injected into each calf after liposuction of the knees and thighs. The patient’s shape and contour demonstrate nice balance and feminine softness.

Case 2: Calf and thigh reconstruction. A 20-year-old Vietnamese female had diminished musculature on the left thigh and calf as a result of childhood polio (Figure 2, page 34). The larger right thigh was suctioned, and 1,200 mL of fat was grafted into the thinner left thigh and calf to improve evenness.

Case 3: Weight-reduction surgery. A 40-year-old mother had abdominoplasty, torso liposuction, and buttock fat grafting (Figure 3, page 34). In the fat-grafting procedure, 800 mL of fat was injected into each buttock to restore a more feminine shape. When larger amounts of fat are grafted, the rate of infection is higher; so we added antibiotics into the graft mixture.

Case 4: Neck reconstruction. A man who received neck radiation for Hodgkin’s disease as a child did not subsequently develop fully in the neck (Figure 4, page 34). He complained that his thin neck gave him an adolescent appearance. Fat was harvested from a nonradiated area and was grafted carefully into the deep neck muscles. The treated area required three graft sessions before a satisfactory result was reached.

Case 5: Grafting following facial rejuvenation. A female had recently recovered from facial-rejuvenation procedures, including face, neck, brow, and eyelid lifts (Figure 5). There had been no strategy for volume restoration, and she complained that she appeared more skeletal than before her facelift. Fat grafting was performed in the temporal, malar, cheek, and nasolabial areas, and around the mouth. The results were subtle, but they showed more facial softness and youthful fullness.

Case 6: Grafting simultaneously with facial rejuvenation. A woman had brow, face, neck, and eyelid lifts, but she needed more improvement around her mouth. She had fat grafts to her cheeks, nasolabial folds, and, most importantly, her marionette lines, resulting in great im­provement (Figure 6).

Case 7: Facial rejuvenation without surgery. The patient wanted to avoid incisions (Figure 7). We carefully used a micrografting technique that involved injecting 120 mL of centrifuged fat into the temporal, cheek, nasolabial fold, lip, paramentum, and chin areas to noninvasively restore facial volume.

What We Have Learned

Fat grafting has proven to be a very useful procedure in plastic surgery for correcting soft-tissue defects and augmenting tissue that has fallen over time as a result of aging. With careful selection of the harvest site, and planning and execution of the procedure, fat grafting can provide excellent results in the hands of a competent plastic surgeon. We believe that this technique should be part of every plastic surgeon’s repertoire of techniques for rejuvenation and body contouring.

Henry A. Mentz, III, MD, FACS, FICS, and Amado Ruiz-Razura, MD, FACS, FICS, practice at the Aesthetic Center for Plastic Surgery in Houston. They can be reached at (713) 799-9999 or dr_mentz@ mybeautifulbody.com.