Autologous fat grafting has been performed for more than one hundred years and there had been a major refinement of fat grafting by Coleman in 1997. Since then, clinical practice using this natural filler is becoming more popular and the results are becoming more consistent. Nowadays autologous fat grafting is utilized broadly for both aesthetic and reconstructive purposes. With the beginning of the twenty first century, adipose stem cell (ASC) was discovered and regenerative medicine is facing a new era of evolution. ASC was applied to fat transfer and 'cell-assisted lipotransfer' technique could be developed. Eto et al. recently presented experimental results of fat graft survival. Their efforts disclosed the important role of ASCs in fat graft, and contributed the progress of fat transfer. Owing to the accumulation of knowledge related with fat graft survival, discovery of ASCs and advancements in surgical techniques, such as Coleman technique and cell-assisted lipotransfer, survival rate of the grafted fat increased and side effects such as fat necrosis decreased. Consequently, there is a new surgical trend of applying large volume fat grafting for augmentation mammoplasty and breast reconstruction with or without silicone implant. Recently, fat grafting is expanding it's limit to new field of treatment of burn, scar, and wound. This article reviews several significant advancements of fat grafting techniques in this century, furthermore intends to widen scientific understandings and contribute to be practiced as a feasible method.
It becomes obvious that fat tissue is not just storage of excess carbohydrate. It is a regenerative complex supporting from the skin surface to deeper organs comprising adult stem cells as well as high energy resource related with tissue repair and regeneration.
Fat grafting technique, which has been performed for more than hundred years, is utilized to improve defects of facial contour, fat atrophy as an aging process and lipodystrophy due comorbid diseases. Nevertheless, the availability had been limited because of variable survival rate in accordance with operators and side effects such as fat necrosis. As Coleman technique was introduced in 1997, however, consistent operative results were obtained and autologous fat grafting has been settled as a reliable natural filler [
Adipose stem cell (ASC), a kind of adult stem cell, was discovered around 2000 and have been studied for more than ten years by scientists and medical doctors. The outcome of scientific research has been accumulated and led ASC to be the core element of regenerative medicine [
As the improvement of surgical techniques in fat surgery, survival rate of the grafted fat increased and side effects such as fat necrosis decreased. As a result, a new surgical trend of large volume fat grafting for breast and buttock augmentation showed consistent operative results, moreover, enabled augmentation mammoplasty without silicone implant [
There have been several important advancements in fat grafting procedure during last ten years. Fat grafting is not a simple procedure transferring fat tissue. With the discovery of ASCs, fat grafting becomes a major tool of regenerative medicine. This article reviews recent advancements in fat grafting techniques helping plastic surgeons to understand and utilize fat transfer scientifically, furthermore intends to suggest the orientation of development in the future.
Rohrich et al. reported that the cell viability of grafted fat is not influenced by donor site [
The Coleman technique reported in 1997 recommends suction with 10 mL syringe to reduce damage applied to fat cell in fat harvesting, and in preparation, removes impurities and oil through 300 rpm (800 g) of proper centrifugal filtration, so raises density of the fat cell in same volume, and in reinjection, uses a thin cannula, 1 mL or 3 mL syringe, so raises possibility of revascularization from surrounding tissue with a method doing distributed arrangement of small aliquots less than 0.1 mL equally in recipient bed. The Coleman technique extended around the globe in a short time and fat grafting began to show improved engraftment rate and stable result, so settleed as a new standard of transplantation of fat [
Afterward, various attempts continued, and it was introduced that a method omitting centrifugation and using washing and straining technique [
Ozsoy reported that in fat reinjection, adipocyte viability on use of 2.5 mm in diameter of a heavy cannula is much higher than adipocyte viability on use of 1.6 mm or 2.0 mm of cannula [
While large volume fat injection for Breast and gluteal augmentation was conducted, there is a problem that Coleman technique holding 1 mL or 3 mL syringe with a hand and injecting gradually is a time-consuming to finish hundreds mL of fat and is difficult to operate for accuracy. A solution for this problem is a screw type syringe (AP Medical, Seoul, Korea) with rotating syringe handle (
In the middle of 1990 having 21st Century called the era of regenerative medicine ahead, plastic surgeons started to study adipose tissue dumped after body contouring surgery as liposuction in Pittsburgh University in United States. They dissociated adipose tissue with collagenase, a histolysis enzyme, and then analyzed stromal vascular fraction obtained by centrifugal filtration of cell suspension. A new type of stromal cells similar to fibroblast were identified showing multipotent differentiation potential, and these new cells are proved to be a kind of adult stem cells through various scientific experiments [
ASC can not only be obtained easily and plentifully from lipoaspirate but also be differentiated into various tissues such as adipocytes, cardiomyocytes, chondrocytes, endothelial cells, myocytes, neuron-like cells, and osteoblasts. So, it is acknowledged that utility of ASCs in regenerative medicine is very high.
If many cultured ASCs are used fully, remedial value of ASCs can be experienced clearly, but many mandatory controls and investment of occupancy expense are necessary to apply cultured ASC to clinics, so full-scale clinical application is not realized yet and ASC is still in the state of clinical trial for several major disease conditions in Korea. Fortunately, even with 20-30 mL of a small adipose tissue is dissociation, quite a number of cells can be obtained, and effectively used in clinics without cultured process. Especially, in ischemic condition, ASC uniformly differentiate into neoangiogenesis, which can be helpful treating postoperative wound problem, radiation necrosis, or ischemic flap of filler-induced skin necrosis [
Another method to increase survival rate of fat grafting is the use of platelet-rich plasma (PRP). It is known that various cytokines released from platelets promote healing process and improve fat graft survival [
More than 100 years passed from first report of fat harvesting [
According to important scientific advances such as refinement of fat grafting, discovery of adipocyte stem cells, and understanding an engraftment process of fat, interest about fat grafting cannot be higher than ever before and it is expanding the limit to new fields such as large volume fat grafting, fat transfer for burn and difficult wounds, and also for scar treatment.
Fat grafting for breast augmentation has been already attempted since several decades ago, but complications of fat necrosis, cyst formation, and infections have long been big issues. However, in these latter days, breast augmentation surgery using cell-assisted lipotransfer increases greatly [
Lately, it is reported that application of the fat tissue to burn wound or extensive wound not only reduces therapy period but also reduces deformity after the end of healing process [
These new trials are very simple and primitive way of utilizing regenerative potential of fat and ASCs for clinical purposes at this age of government regulation. Near future, the ultimate form of stem cell therapy using cultured pure ASCs can be put into use effectively and efficiently.
Future fat grafting may not be simple fat tissue grafting. It may be more like fat cell grafting or fat tissue engineering incorporating adipocytes, ASCs and adequate scaffold materials. Cell-assisted lipotransfer could be upgraded by enrichment with adequate number of cultured ASCs which significantly affect the engraftment of graft fat.
Full-scale clinical application of stem cell therapy is delayed by legal control to ensure patients’ safety, but the effect of stem cell therapy have been already proved through scientific verification during the past decade. Only if enough number of cultured ASC can be used in clinics as needed, era of regenerative medicine with stem cell therapy can fully open for the first time.
The business of stem cell bank have already started by ambitious investors, but it is early to create a profit yet. It may not be easy for ordinary people to spend large amount of money to preserve their own stem cells in advance for unrealized further medical techniques. However, to benefit from stem cell therapy that will be developed newly and continuously in the future, cryopreservation of own stem cells early in life will be an important medical option before long.
Scientific knowledge about fat and fat tissue transfer are accumulating rapidly. Fat is a unique regenerative complex comprising adult stem cells as well as high energy resource related with tissue repair and regeneration. The regenerative potential of fat tissue led us to expand the limit of application day by day. Fat tissue is expected to be an essential component of regenerative medicine in the twenty first century and it is essential for plastic surgeons to understand new knowledge on fat biology to perform better and reasonable clinical practice.
This Work was supported by a graft from the Chunma medical research foundation, Korea 2006.
No potential conflict of interest relevant to this article was reported.
Screw type syringe. (A) A disposable screw type syringe. (B) A metallic screw type syringe adapter fitted for 20 mL disposable syringe.
Placement of graft fat in two different techniques are designed to increase surface of contact with recipient vascular bed in given situation. (A) Coleman technique and screw type syringe technique. (B) screw type syringe technique.
Early cell death and replacementof adipocytes. Eto H, Kato H, Suga H, Aoi N, Doi K, Kuno S, Yoshimura K. The fate of adipocytes after nonvascularized fat grafting: evidence of early death and replacement of adipocytes. Plast Reconstr Surg 2012;129:1081-92.