PART V
AESTHETIC SURGERY
CHAPTER 44 FAT GRAFTING IN PLASTIC SURGERY
LOUIS P. BUCKY, IVONA PERCEC, AND DANIEL DEL ALEXANDER VECCHIO
INTRODUCTION
The role of autologous fat grafting or fat auto-transplantation in plastic surgery has evolved from a controversial technique designed for simple volume augmentation to the foundation for the innovative and burgeoning field of regenerative medicine. Neuber (1893) initially reported the use of small pieces of fat from the upper arm to reconstruct a depressed area of the face resulting from tuberculous osteitis. Today, fat grafting plays diverse and far-reaching roles in plastic surgery. Its application currently extends from simple volume augmentation of the face to total reconstruction of a post-mastectomy breast. Because many of the variables in fat transplantation were not well understood initially, early results with fat grafting were disappointing, and the technique was largely abandoned.
Recent enhancements in fat grafting applications lie not only in more reliable volume augmentation to the face, breast, and buttocks, but perhaps more importantly in pioneering the potential regenerative aspects of fat via its rich source of stem cells. Though fat grafting to the face has been used relatively consistently since the introduction of the Coleman technique in the mid-1990s, fat transplantation to the breast and body was largely abandoned for more than 20 years. By 2006, reports of fat transplantation emerged in presentations and in case report papers suggesting the long-term viability of fat transplantation to the breast. In 2007, Coleman published his review of 17 patients who were grafted using autologous fat and were followed up with serial photography. The specific grafting techniques employed in a given case depend upon a series of factors, including the characteristics of the recipient site, the goals of surgery (volume and shape), and abundance of donor tissue. Because of the intrinsic differences in fat grafting to the face versus the body, this chapter has been divided into fat grafting applications for cosmetic and reconstructive uses in the face followed by large volume fat grafting applications for the breast and body.
FACIAL FAT GRAFTING
Autologous fat grafting to the face provides a naturally appealing solution to a vital aspect of facial aging. Soft tissue loss or deflation occurs routinely in middle-aged adults. As fat content is reduced, soft tissues collapse and the face globally “deflates” permitting gravitational changes to arise. Lipoatrophy in the face can also result from disorders such as Perry-Romberg syndrome, trauma, and infection. Hypoplasia of fat can be congenital, as in hemifacial microsomia (Figure 44.1). The use of fat as a filler for volume restoration of the face is optimal due to its easy acceptance, excellent safety profile, and natural appearance and feel. Historically, the major limitation of fat grafting has been unpredictability of “take” or viability, typically ranging from 40% to 60% of what has been grafted. In our experience, small volume fat grafting to the face behaves like other biologic grafting in that it requires adequate vascularization of grafted tissue for long-term viability. Fat grafting to the face, as opposed to the body, utilizes concentrated smaller volumes of fat, typically 20 to 60 cc of purified fat. Since large volumes are not necessary, and overfilling is undesirable in the face, gentle harvest, adequate processing, and small volume injection become even more paramount as the tenets of successful fat grafting technique.
Managing the Variables—From Donor to Recipient
Donor and Harvest. The most common graft donor sites are the hips, saddlebags, thighs, abdomen, and inner knee. There are no data that suggest one anatomical site is superior to another, yet all donor sites need to have adequate fat volume to avoid a potential concavity or dimpling deformity after harvest. Infrequently, harvesting from more than one site is necessary to acquire sufficient volume for grafting. Pre-infiltration with dilute lidocaine and epinephrine into donor sites typically provides adequate graft volume, hemostasis, and analgesia. Most surgeons employ a version of the Coleman technique that calls for gentle suction through small 10 cc syringes and microinjection using 1 cc blunt-end cannulae. Usually, this technique results in a 3:1 ratio of harvested to purified fat.
Fat Preparation. Fat must be processed to separate oil, blood, and lidocaine from potentially viable fat cells. This can be accomplished by gravity sedimentation, by centrifugation, by Telfa pad rolling, or by a combination of these techniques. There are no current data to suggest one technique is superior to another. Irrespective of purification technique, the limitation of ischemic time and cellular trauma should be a priority. For low volume augmentation, we prefer gravity sedimentation followed by Telfa rolling until the fat becomes yellow in color and thick in consistency, as unwanted fluids are absorbed. The fat is then gently transferred into 1 cc syringes prior to injection (Figure 44.1).
Fat Grafting Injection. Small aliquots of fat are microinjected into discrete facial units using a 1 cc syringe, with the goal of predictable viability and avoidance of contour irregularities (Figure 44.2). Areas of the face that have the least motion have the best survival outcomes. Therefore, the deep compartments of the cheek, malar, and upper nasolabial folds are excellent recipient sites due to their relative immobility, preexisting fat content, and depth of location (Figure 44.1). The perioral region, lips, marionettes, and lower nasolabial folds are more variable due to significant motion and thinner overlying tissues (Figure 44.3). In contrast, the periorbital region has excellent survival of small volumes, but is perhaps the most challenging due to its thin, delicate, and unforgiving nature. Filling to the periorbital region should be limited to small volumes using small blunt cannulae with injections placed under the orbicularis oculi muscle. In areas of significant motion such as the glabella, results are best obtained when fat infiltration is preceded by neuromodulation to limit muscle motion. Additional regions where fat grafting can be used successfully are the temples, forehead, prejowl sulci, and labiomental crease.
FIGURE 44.1. Small syringe technique for facial fat grafting. Telfa-processed fat is loaded into 1 cc syringes and injected using small, typically blunt cannulae (A, B). Long-term treatment of right facial lipoatrophy secondary to Parry-Romberg syndrome with fat grafting: preop (C), 6 months postop, (D), and 8 years postop (E). (Patient of Louis Bucky, MD.)
FIGURE 44.2. Small syringe technique for facial fat grafting. Long-term correction of age-related lipoatrophy with isolated fat grafting: preop (A), 6 months postop (B), and 2 years postop (C). (Patient of Louis Bucky, MD.)
Complications. The complications of facial fat grafting are typically limited to contour irregularities secondary to superficial placement and fat necrosis, frequently in the older patient. Both usually necessitate direct excision. Variable graft survival is still common, though it can be limited by attention to detail, careful preparation, and infiltration. The two most significant complications are intravascular injection and overgrafting. Fortunately, these phenomena are exceedingly rare. Injection injury can be limited by using blunt cannulae and low-pressure injection in a layered fashion. On the contrary, overgrafting is becoming an increasing problem due to large volume injection, as practitioners become more at ease with fat grafting techniques. This is seen more frequently in younger patients who have had superficially placed injections. Unfortunately, weight gain causes all fat grafts to enlarge, which, in the face, can result in significant and disproportionate distortion. The treatment of overgrafting requires microliposuction with only limited improvements and risks of excessive scar formation. Therefore, even for experienced surgeons, it is recommended to use small to moderate grafts in the face with minimal overfilling in most patients.
FIGURE 44.3. Small syringe technique for facial fat grafting. Long-term correction of age-related lipoatrophy with isolated fat grafting. Fat grafting augmentation of the lips, 3 cc total, preop (A), 6 months postop (B). Fat grafting to the nasolabial folds, perioral area and malars, 20 cc total, in conjunction with rhytidectomy, preop (C), 2 years postop (D). (Patients of Louis Bucky, MD.)
LARGE VOLUME FAT GRAFTING
Large volume fat grafting required for effective body augmentation and reconstruction has to be distinguished from the relatively smaller volume fat grafting needed to improve small breast contour defects or to restore age-related fat atrophy in the face. In the former category, small volumes of fat on the order of 30 to 100 cc are used, and these procedures are not performed using pre-expansion. To build an entirely natural breast or buttock from fat is a completely different procedure requiring a modified strategy and application of the principles of fat transplantation. Nevertheless, success in large volume fat transplantation requires meticulous analysis of similar variables to small volume grafting: donor and recipient site and the surgical technique. In mega-volume fat transplantation, it is paramount to optimize the entire technique, rather than maximize any one factor of the process, as described below (Table 44.1).
Managing the Variables—From Donor to Recipient
Donor and Harvest. There is no current scientific evidence that the anatomic location of the donor site is significant to clinical outcomes. Rather, adipocyte cell size, which varies between different anatomical depots and also between patients, may be the more important variable. The use of smaller harvest cannula sizes creates less donor site trauma resulting in smaller, more uniform lobules of fat, which may in turn improve flow characteristics during graft injection. Although there are several harvesting technology platforms including water jet–based, laser-assisted, and ultrasonic-assisted systems, there are to date no published clinical results that demonstrate the benefits of any of these technologies over fat harvested with a standard tumescent liposuction or power-assisted system. Harvesting the fat can be accomplished at less than 1 atm (760 mm Hg), with a mechanical liposuction aspirator vacuum source or with a handheld syringe.
Fat Preparation. Centrifuging lipoaspirate at 1,300 times the force of gravity (1,300G) for 3 minutes is the method of fat processing most commonly used for facial or small volume fat grafting. The penchant for centrifugation arose from the need to graft as much adipocyte biomass as possible into a limited space. Although centrifugation can yield concentrated fat, there are four potential problems with this strategy when applied to mega-volume fat transplantation: cellular damage, time and labor consumption, clumping, poor flow, and lower engraftment potential from excessively high fat concentrations. Advances in pre-expansion of the recipient site have emancipated fat grafting from the need for high-speed centrifugation and its potential disadvantages. In the expanded space, a larger amount of loose fat slurry can be more diffusely dispersed and may survive better. Using a hand-crank syringe centrifuge, fat loaded in 60 cc syringes can be efficiently separated from crystalloid with little trauma at 20 to 40G (Figure 44.4).
Fat Grafting Injection. There are currently two established methods of mega-volume fat grafting—the “mapping” technique and the “reverse liposuction” technique. Reverse liposuction refers to a constant motion of the injection cannula while fat is injected. In the mapping technique, fat is injected upon axial withdrawal of the needle only. Generally, soft pliable nonscarred tissues without underlying implants can be treated more efficiently with reverse liposuction, while grafting in scarred, or irradiated beds, or over implants requires the mapping approach.
FIGURE 44.4. Large syringe technique. Decanted fat (A, B) is loaded into 60 cc syringes and is spun for 2 minutes at 40G (C). Fat that looks like “pure fat” at 1G (D) is actually 20% crystalloid when spun at 40G (E).
Recipient Site Management. Recipient site management has only recently been suggested as an important variable in fat grafting (Table 44.2). The size, vascularity, and compliance of the recipient site are the most prominent components. The BRAVA® bra was developed as an external soft tissue expander to enlarge the breast. As long as the device is worn continuously for 10 to 12 hours per day for several months, reliable and enduring augmentation of the breast volume ensues (Figure 44.5). The increased subcutaneous space created by BRAVA pre-expansion allows more graft volume to be inserted before high subcutaneous interstitial pressures are reached, thereby requiring less concentrated fat. Because less concentrated fat flows more easily and can be inserted at lower pressures via larger sized syringes, the procedure time using this approach is reduced from 6 to 2 hours, and volumes injected can reach 700 cc. The use of BRAVA for external pre-expansion prior to the fat grafting can serve two additional valuable roles in re-shaping breasts: deformities can be demonstrated to the patient prior to any surgical intervention and during fat grafting, and internal scar ligaments can be selectively lysed using a “percutaneous 3D meshing” technique to reshape the breast immediately after grafting the fat.
AESTHETIC AND ANATOMIC CONSIDERATIONS
From augmentation enhancement of an existing perfectly shaped breast with fat (Figure 44.6) to the multistage creation of a breast mound in a post-mastectomy patient (Figure 44.7), the technique of nonsurgical pre-expansion and autologous fat grafting exhibits a spectrum of different fill effects. Generally, the more parenchyma one has to begin with the larger volumes of fat that can be grafted. Smaller or otherwise constricted breasts require on average more sessions to achieve the same final volume because smaller breasts cannot expand as much as larger breasts. Dense or irradiated breasts also expand with more difficulty than soft, multiparous breasts and thus these patients must be encouraged to increase the negative pressure on the BRAVA domes to achieve an adequate expansion preoperatively. These patients require the highest number of grafting sessions and three-dimensional release of internal scarring. The anticipated volume of grafting will therefore depend on the preoperative assessment of the recipient volume. The “V/C” ratio, the volume of graft to the recipient site capacity ratio, must be appreciated and must not exceed 1:1. That is, for any given volume of recipient site, one cannot exceed this volume in graft material. The more pathology in the site (radiation damage) the lower this V/C ratio must be to avoid overgrafting the recipient site. For irradiated cases, one should be extremely careful not to overgraft and should expect a minimum of four to five sessions. The long-term incidence of cysts and masses and calcifications following mega-volume fat transplantation to the breast is not well established but may range from 10 to 20%. The variability of the clinical applications and techniques likely accounts for the range.
CONTROVERSIES AND FUTURE DIRECTIONS
At the time of this publication, we are in the initial phases of using fat transplantation for breast augmentation and reconstruction. Currently, there are still more questions than answers. The following topics represent some of the biggest controversies and challenges facing this technique in the future.
Imaging and Detection of Breast Cancer Risk: In 1987, the American Society of Plastic Surgeon position paper strongly condemned fat grafting to the breast suggesting that fat grafting would distort breast cancer detection secondary to the formation of postgrafting calcifications. However, these calcifications have been classified as Bio-RAD 1-2, and are generally felt to be easily distinguishable from calcifications of higher grade that are suggestive of malignancy, when digital mammography is used. While fat grafting to the breast is still in its infancy, it is important to establish safety standards for patients and clinicians for the future. The establishment of an international registry of breast fat grafting patients, followed over a 40- to 50-year period, will be necessary to compare this cohort of women with the general population and examine statistical differences in breast cancer detection and incidence.
FIGURE 44.5. The BRAVA external tissue expander worn by a patient just prior to the fat grafting procedure (A). Patient pre-BRAVA Expansion (B) and 3 weeks post-BRAVA expansion (C), immediately prior to grafting. Note the volumetric increase is three to four times that of the pre-expansion state. A total of 480 cc of fat was subsequently injected in this case into each breast. (Patient of Daniel Del Vecchio, MD.)
FIGURE 44.6. Laterally constricted breasts, pre-expansion (A) and 6 months postoperative (B) with fat transplantation. This patient required aggressive release of the lateral mammary constrictions to achieve this lateral roundness and fullness. (Patient of Daniel Del Vecchio, MD.)
Role of Stem Cell Enrichment: Enriching processed fat grafts with adipose stem cells has been proposed to increase cell viability in grafting. The theoretical benefit of a stem cell–enriched fat graft is that the additional stem cells improve volume and viability through the differentiation of new adipocytes and stromal vascular cells. In small volume fat transplantation, especially where there may be a need for regenerative effects, stem cell–enriched fat may have early clinical relevance. Although this may be an effective strategy for the future, this stem cell technique is neither clinically proven nor Food and Drug Administration approved at the time of this writing, and the authors therefore do not employ this method. More importantly, basic science advances in adipose tissue and stem cell biology are likely to provide critical contributions and advancements in both small and large volume fat grafting applications. Over the next decade, we must optimize clinical fat grafting through technique refinement and standardization, and we must carry on our history of innovation by incorporating anticipated scientific advancements in adipose tissue biology.
FIGURE 44.7. Bilateral breast reconstruction in a non-mastectomy patient. When there is a relatively large starting capacity preoperatively (A), primary core volume reconstruction can be performed in one stage using pre-expansion (B). (Patient of Daniel Del Vecchio, MD.)
Suggested Reading
Baker T. Presentation on BRAVA Non-surgical Breast Expansion. ASAPS 2006 Annual Meeting, Orlando, FL.
Bucky LP, Percec I. The science of autologous fat grafting: views on current and future approaches to neoadipogenesis. Aesthet Surg. 2008;28(3):313-321.
Coleman SR, Saboeiro AP. Fat grafting to the breast revisited: safety and efficacy. Plast Reconstr Surg. March 2007;119(3):775-785.
Coleman SR. Structural fat grafting: more than a permanent filler. Plast Reconstr Surg. 2006;118(suppl 3):108D-120S.
Czerny V. Plastischer Ersatz der Brustdruse durch ein Lipom. Zentralbl Chir. 1985;27:72.
Del Vecchio DA, Bucky LP. Breast augmentation using pre-expansion and autologous fat transplantation- a clinical radiological study. Plast Reconstr Surg. June 2011;127(6):2441-2450.
Del Vecchio DA, Rohrich RJ. A classification of clinical fat grafting—different problems, different solutions. Plast Reconstr Surg. 2012;130(3):511-522.
Gutowski KA. Current Applications and Safety of Autologous Fat Grafts: A Report of the ASPS Fat Graft Task Force. Evanston, IL: ASPS Fat Graft Task Force; 2009.
Heit YI, Lancerotto L, Mesteri I, et al. External volume expansion increases subcutaneous thickness, cell proliferation and vascular remodeling in a murine. Plast Reconstr Surg. 2012;130(3):541-547.
Kanchwala, Suhail K, Glatt, BS, Conant EF, Bucky LP. Autologous fat grafting to the reconstructed breast: the management of acquired contour deformities. Plast Reconstr Surg. August 2009;124(2):409-418.
Khouri RK, Schlenz I, Murphy BJ, Baker TJ. Nonsurgical breast enlargement using an external soft-tissue expansion system. Plast Reconstr Surg. June 2000;105(7):2513-2514.
Melvin A. Shiffman MD, Sid Mirrafati MD. Fat transfer techniques: the effect of harvest and transfer methods on adipocyte viability and review of the literature. Dermatol Surg. 2001;27(9):819-826.