Structural fat grafting: more than a permanent filler

Adipogenic differentiation of human adipose tissue-derived stem cells obtained from cryopreserved adipose aspirates

BACKGROUND

Although frozen adipose tissue is frequently used for soft tissue augmentation, the viability of frozen fat remains a controversy. The cryopreservation of adipose tissue is important for the future use of adipose-derived stem cells (ASCs) and adipocytes.

OBJECTIVE

To determine whether optimal cryopreservation techniques with regard to the addition of cryopreservative agents and preservation temperature is essential for the long-term storage of adipose tissue and whether ASCs from cryopreserved adipose aspirates are reliable for use in adipogenic differentiation.

MATERIALS AND METHODS

Adipose tissue was frozen directly or with cryoprotectant at -20 degrees C or -80 degrees C for 1 year. The viability of adipose aspirates and the differentiation of ASCs isolated from adipose tissue were evaluated.

RESULTS

The viability of adipose aspirates frozen with dimethyl sulfoxide at -80 degrees C was approximately 87% after 2 months of storage. Moreover, ASCs from adipose tissue stored with cryoprotectant survived successfully for 1 year and differentiated into adipocytes, although ASCs were not detected in the directly frozen adipose tissue.

CONCLUSION

Adipose tissue cryopreserved with cryoprotectant and stored at optimal temperature might prove to be a reliable source of human ASCs and adipocytes.

Determining the oncological risk of autologous lipoaspirate grafting for post-mastectomy breast reconstruction

This study compares the incidence of local and regional recurrence of breast cancer between two contiguous time windows in a homogeneous population of 137 patients who underwent fat tissue transplant after modified radical mastectomy. Median follow-up time was 7.6 years and the follow-up period was divided into two contiguous time windows, the first starting at the date of the radical mastectomy and ending at the first lipoaspirate grafting session and the second beginning at the time of the first lipoaspirate grafting session and ending at the end of the total follow-up time. Although this study did not employ an independent control group, the incidence of local recurrence of breast cancer was found to be comparable between the two periods and in line with data from similar patient populations enrolled in large multicenter clinical trials and who did not undergo postsurgical fat tissue grafting. Statistical comparison of disease-free survival curves revealed no significant differences in relapse rate between the two patient subgroups before fat grafting and after fat grafting. Although further confirmation is needed from multicenter randomized clinical trials, our results support the hypothesis that autologous lipoaspirate transplant combines striking regenerative properties with no or marginal effects on the probability of post-mastectomy locoregional recurrence of breast cancer.

Potential application of adipose-derived stem cells and their secretory factors to skin: discussion from both clinical and industrial viewpoints

IMPORTANCE OF THE FIELD

Adipose tissue is one of the richest sources of mesenchymal stem cells. Even more interesting is the fact that adipose-derived stem cells (ASCs) show an outstanding ability to regenerate damaged skin. Thus, ASCs are a popular and feasible treatment in clinical dermatology.

AREAS COVERED IN THIS REVIEW

This review discusses the potential applications of ASCs and conditioned medium of ASC (ASC-CM) to skin, and briefly touches on the mechanisms by which ASCs promote skin regeneration.

WHAT THE READER WILL GAIN

Clinically, processed lipo-aspirated (PLA) cells are commonly used for treatment of aged skin; however, the use of PLA cells for cosmetic purposes is not convenient, because PLA cells are prepared from patients. Alternatively, cosmetics that contain ASC-CM can be pre-made from healthy volunteers such that they are immediately available for clinical treatment of aged skin. Cell-based therapies are adequate for improvement of wrinkles or for soft tissue augmentation, whereas ASC-CM has merit for amelioration of skin tone. When culturing ASCs for the production of cosmetic raw materials, hypoxic culture conditions and transduction of specific genes into ASCs may increase the regenerative protein content of the conditioned medium.

TAKE HOME MESSAGE

Application of ASCs and ASC-CM to dermatology shows promising results for skin regeneration.

Current applications and safety of autologous fat grafts: a report of the ASPS fat graft task force

TASK FORCE STATEMENT: In 2007, the American Society of Plastic Surgeons formed a task force to conduct an assessment regarding the safety and efficacy of autologous fat grafting, specifically to the breast, and to make recommendations for future research. The task force formulated specific issues regarding fat grafting and then compiled them to focus on five broad-based questions: 1. What are the current and potential applications of fat grafting (specifically breast indications, and if data are available, other cosmetic and reconstructive applications)? 2. What risks and complications are associated with fat grafting? 3. How does technique affect outcomes, including safety and efficacy, of fat grafting? 4. What risk factors need to be considered for patient selection at this level of invasiveness? 5. What advancements in bench research/molecular biology potentially impact current or future methods of fat grafting? To answer these questions, the task force reviewed the scientific literature, critically appraised the information available, and developed evidence-based practice recommendations. Although the primary issue of interest was fat grafting to the breast, other aspects of fat grafting were evaluated.

Adipocyte transplantation and stem cells: plastic surgery meets regenerative medicine

The technologies for adipose tissue harvesting, processing, and transplantation have substantially evolved in the past two decades. Clinically driven advancements have paralleled a significant improvement in the understanding of cellular, molecular, and immunobiological events surrounding cell and tissue transplantation. These new mechanistic insights could be of assistance to better understand the mechanisms underlying some of the observed clinical improvements. In addition to plastic and reconstructive surgical applications, adipose tissue has become central to an increasing number of translational efforts involving adipose tissue-derived progenitor cells. The growing interest in this area of research has resulted in the exploration of many novel research and clinical applications that utilize adipose tissue grafting and/or progenitor/stem cell- derived cell products obtained from this tissue source. Progenitor, endothelial, and mesenchymal stem cells derived from adipose tissue could therefore not only be central to plastic and reconstructive surgery applications, but also become the focus of an array of therapeutic solutions for many disease conditions, such as those affecting bone, cartilage, muscle, liver, kidney, cardiac, neural, and the pancreas, expanding the possible indications and translational potential of tissue, cell-based, and regenerative medicine strategies.

Treatment of chronic anal fissures and associated stenosis by autologous adipose tissue transplant: a pilot study

PURPOSE

A substantial body of recent evidence suggests that autologous adipose tissue transplant promotes healing in different lesions associated with local ischemia. We report the outcome of lipoaspirate transplant in hard-to-treat chronic anal fissures.

METHODS

Eight patients were included in this pilot study, 5 with single and 3 with multiple fissures. All had intense anal pain and had previously undergone proctologic surgery, with internal sphincterotomy performed in 6 patients. Severe stenosis was present in 3 patients and moderate stenosis in 2. Preoperative assessment included anoscopy, anorectal manometry, colonoscopy, and microbiological tests to exclude inflammatory, neoplastic, or infectious diseases. Surgical treatment consisted of transplant of purified autologous fat retrieved from the hypogastrium. Follow-up was scheduled after 1 week, at 2, 3, 6, and 12 months, and thereafter on a yearly basis.

RESULTS

All of the patients were discharged several hours after surgery. No early postoperative complication was observed. Complete healing and pain remission were achieved in 6 patients (75%), 4 of whom were treated in a single session, whereas 2 patients required 2 and 3 sessions. Anal stenosis was resolved in 4 of 5 patients (80%). The therapy was unsuccessful in 2 patients (25%). Mean follow-up was 18 months (range, 3-36 months).

CONCLUSION

Perianal autologous fat transplant can be safely performed for the treatment of complex anal fissures. It is well tolerated and offers encouraging results, although further research is warranted because of the small number of patients treated and the relatively short follow-up time.

A new method for cryopreserving adipose-derived stem cells: an attractive and suitable large-scale and long-term cell banking technology

Recent studies have shown potential ways for improving stem cell cryopreservation. The major need for autologous stem cell use is a long-term storage: this arises from the humans' hope of future use of their own cells. Therefore, it is important to evaluate the cell potential of vitality and differentiation before and after cryopreservation. Although several studies have shown a long-term preservation of adipose tissue, a few of them focused their attention to stem cells. The aim of this study was to evaluate the fate of cryopreserved stem cells collected from adipose tissue and stored at low a temperature in liquid nitrogen through an optimal cryopreservation solution (using slowly cooling in 6% threalose, 4% dimethyl sulfoxide, and 10% fetal bovine serum) and to develop a novel approach to efficiently preserve adipose-derived stem cells (ASCs) for future clinical applications. Results showed that stem cells, after being thawed, are still capable of differentiation and express all surface antigens detected before storage, confirming the integrity of their biology. In particular, ASCs differentiated into adipocytes, showed diffuse positivity for PPARgamma and adiponectin, and were also able to differentiate into endothelial cells without addition of angiogenic factors. Therefore, ASCs can be long-term cryopreserved, and this, due to their great numbers, is an attractive tool for clinical applications as well as of impact for the derived market.

Human adipose-derived stem cells isolated from young and elderly women: their differentiation potential and scaffold interaction during in vitro osteoblastic differentiation

BACKGROUND AIMS

Several authors have demonstrated that adipose tissue contains multipotent cells capable of differentiation into several lineages, including bone, cartilage and fat.

METHODS

This study compared human adipose-derived stem cells (hASC) isolated from 26 female donors, under 35 and over 45 years old, showing differences in their cell numbers and proliferation, and evaluated their in vitro adipocytic and osteoblastic differentiation potential.

RESULTS

The cellular yield of hASC from older donors was significantly greater than that from younger donors, whereas their clonogenic potential appeared slightly reduced. There were no significant discrepancies between hASC isolated from young and elderly women regarding their in vitro adipocytic differentiation, whereas the osteoblastic potential was significantly reduced by aging. We also assessed the influence of hydroxyapatite (HAP) and silicon carbide (SiC-PECVD) on hASC. Even when cultured on scaffolds, hASC from younger donors had better differentiation into osteoblast-like cells than hASC from older donors; their differentiation ability was up-regulated by the presence of HAP, whereas SiC-PECVD produced no significant effect on hASC osteoblastic differentiation.

CONCLUSIONS

The large numbers of hASC resident in adipose tissue and their differentiation features suggest that they could be used for a successful bone regeneration process in vivo. We have shown that age does not seem to affect cell viability and in vitro adipocytic differentiation significantly, whereas it does affects osteoblastic differentiation, in the absence and presence of two-dimensional and three-dimensional scaffolds.

Long-Term Acoustic Comparison of Thyroplasty versus Autologous Fat Injection

Objectives:

Medialization by thyroplasty or intracordal autologous fat injection provides voice improvement in patients with unilateral vocal fold paralysis. Thyroplasty is considered a “permanent” medialization, whereas fat injection is considered “temporary” because of reabsorption. The objective of this study was to compare the evolution of acoustic parameters for these procedures over 1 year and to evaluate the results of fat injection at 2 years.

Methods:

From 1994 to 1998, 46 consecutive patients (17 women and 29 men) were treated exclusively by intracordal injection of autologous fat, and then from 1999 to 2002, 48 consecutive patients (19 women and 29 men) were treated with the Montgomery Thyroplasty Implant System or Gore-Tex thyroplasty. Each patient's voice was prospectively recorded before operation and at 1, 3, 12, and 24 months after operation. Six patients (13%) in the injection group underwent a second injection, and 1 patient (2%) in the thyroplasty group underwent revision surgery. Jitter, shimmer, and noise-to-harmonics ratio (NHR) were calculated for a 1,000-ms midvowel segment of the vowel / a/.

Results:

One month after operation, jitter, shimmer, and NHR were significantly improved in both groups (Wilcoxon's test, p < 0.05 in all cases). Jitter and shimmer did not change significantly between 1 and 3 months or between 1 and 12 months (p > 0.05). The NHR had improved at 12 months in both groups (injection, p = 0.0004; thyroplasty, p = 0.0178) and at 24 months in the injection group (p = 0.0076). No significant difference was noted between the two techniques before operation or at 1, 3, or 12 months after operation (Mann-Whitney test, p > 0.05). Jitter and shimmer had not changed significantly after 24 months in either group. At 24 months, there was no difference in acoustic parameters between the two treatment groups.

Conclusions:

The two techniques provided comparable objective acoustic voice improvement. At 2 years, autologous fat injection provides long-term acoustic voice improvement comparable to that of thyroplasty, but it has a higher rate of revision surgery.

Perforator flaps: recent experience, current trends, and future directions based on 3974 microsurgical breast reconstructions

Perforator flap breast reconstruction is an accepted surgical option for breast cancer patients electing to restore their body image after mastectomy. Since the introduction of the deep inferior epigastric perforator flap, microsurgical techniques have evolved to support a 99 percent success rate for a variety of flaps with donor sites that include the abdomen, buttock, thigh, and trunk. Recent experience highlights the perforator flap as a proven solution for patients who have experienced failed breast implant-based reconstructions or those requiring irradiation. Current trends suggest an application of these techniques in patients previously felt to be unacceptable surgical candidates with a focus on safety, aesthetics, and increased sensitization. Future challenges include the propagation of these reconstructive techniques into the hands of future plastic surgeons with a focus on the development of septocutaneous flaps and vascularized lymph node transfers for the treatment of lymphedema.

Effect of autologous platelet adhesives on dermal fat graft resorption following reconstruction of a superficial parotidectomy defect: a double-blinded prospective trial

BACKGROUND

Dermal fat grafts are used to reconstruct facial contour defects but may undergo variable resorption. Application of autologous platelet adhesive may improve outcomes. The primary objective was to compare resorption of dermal fat grafts for parotidectomy defects, between patients receiving autologous platelet adhesive versus controls.

METHODS

This was a double-blinded prospective cohort at a tertiary care center. Volumetric analyses of dermal fat graft measured by MRI scans. Resorption was determined by comparing 1- and 6-month MRIs in each patient. Complications, Frey's Syndrome, and patient satisfaction were also assessed.

RESULTS

Twelve patients completed the study. A significant reduction in graft resorption was seen in the treatment group (57% vs. 31%, p = .01). Three patients in the control group developed fat liquefaction. Patient perceived significant differences in scar and contour.

CONCLUSION

Application of autologous platelet adhesives improved graft viability and patient satisfaction at 6 months.

Viability of preadipocytes in vitro: the influence of local anesthetics and pH

BACKGROUND

Autogenous fat transfer with lipoinjection for soft tissue augmentation is a commonly used surgical technique. Abundant donor tissue availability and relative ease of harvesting have made autologous fat an attractive soft tissue filler. The overall reliability of this technique is often disputed, and different authors describe different results after autologous fat transplantation despite using similar techniques. In this study, we examined the influence of different local anesthetics commonly used in fat harvest and the pH of the anesthetic solution on the viability of harvested preadipocytes.

METHODS AND MATERIALS

Preadipocytes were incubated with 1% lidocaine, 1% articaine plus epinephrine 1:200,000, 0.75% ropivacaine, and 1% prilocaine or our standardized tumescent solution (1 L of 0.9% sodium chloride solution plus 25 mL of 1% articaine plus epinephrine 1:200,000 plus 25 mL of bicarbonate) for 30 minutes. Additionally, we incubated cells with the local anesthetics as described above but diluted 1:2 with phosphate buffered saline (pH 7.4). Viability was measured using trypan blue dying as well as propidium iodine staining and fluorescence-activated cell sorting analysis.

RESULTS

There are significant differences in the viability of preadipocytes under the influence of various local anesthetics.

DISCUSSION

Our data could partially explain the varying results after autogenous fat transfer.

Fat grafting in trauma and reconstructive surgery

The midface of youth is a full, vertically well-supported structure. Aging brings deflation of the midface associated with vertical descent. Reversal of this volume loss with fat grafting or other fillers has become a major recognized goal of aesthetic surgeons today. Fat grafting in reconstructive surgery is not a new concept. Excellent results may be achieved in most reconstructive and cosmetic surgery cases with well-executed lipotransfer. Attention to detail is important for rewarding results. Graft resorption can occur even in well-executed cases and patients should be appropriately cautioned.

The scientific basis for lipotransfer: is it the ideal filler?

A loss of volume results from a reduction in the subcutaneous fat, muscle atrophy, and changes in skeletal framework. Such loss of tissue volume compounded with tissue laxity leads to the aged appearance of the periorbital, perioral, cheek, and mandibular areas. Many facial plastic surgeons have sought to replace this volume with various injectable agents, both synthetic and autologous, in search for the ideal soft tissue filler. This article reviews the literature on lipotransfer and specifically the scientific basis underlying the approach.

Body shaping and volume restoration: the role of hyaluronic acid

Driven by the rising popularity of minimally invasive techniques, the demand for cosmetic procedures is increasing. Cosmetic body-shaping procedures can be categorized into those that remove tissue and those that add volume. This review focuses on the latter of these categories, particularly on the use of resorbable hyaluronic acid gels specifically developed for minimally invasive volume enhancement. Pilot studies of hyaluronic acid involving its injection to contour various body deformities and its recent use in female breast augmentation are discussed. Injectable hyaluronic acid is effective and well tolerated. It represents an attractive treatment option for volume restoration or augmentation by providing predictable long-lasting results after minimally invasive administration. Alternative treatment options for volume enhancement also are summarized including fat transfer, silicone implants, and the use of injectable nonresorbable products such as silicone, polyalkylimide, and polyacrylamide gels. As patients continue to opt for nonsurgical procedures that offer predictable results, the development of minimally invasive products such as hyaluronic acid is increasingly important.

Regenerative surgery: use of fat grafting combined with platelet-rich plasma for chronic lower-extremity ulcers

BACKGROUND

The authors present their experience with reconstructive surgery of the lower extremity for chronic ulcers, evaluating the effects related to the use of a platelet-rich plasma combined with fat tissue.

METHODS

A total of 20 patients, 25 to 50 years of age (median age, 40 years), have been managed with platelet gel in the Plastic and Reconstructive Surgery Department at the "Tor Vergata," University of Rome. The patients were affected by both lower-extremity chronic ulcers and vascular disease.

RESULTS

The authors observed that 16 of 20 chronic lower-extremity ulcers reepithelialized during an average of 9.7 weeks, with platelet releasate suspended on a collagen base (platelet-derived wound-healing factor), compared with 2 of 10 similar wounds treated with medication based on hyaluronic acid and collagen. Collectively, these data provide evidence for the clinical use of platelet technology in the healing of both soft and hard tissue wounds.

CONCLUSIONS

Currently, plastic surgery with autogenous fat grafts can be performed for stabilization of chronic lower-extremity ulcers. The objective of this study was, through the presentation of clinical cases, to suggest a therapeutic plan formed by two sequential treatments: acquisition of platelet gel from a small volume of blood (9-18 ml) followed by the Coleman technique for reconstructing the three-dimensional projection and superficial density of tissues. The results proved the efficacy of combining these two treatments, and the satisfaction of the patients confirmed the quality of the results.

Adipose-derived stem cells for soft tissue reconstruction

In soft tissue repair, there are several surgical options such as nondegradable, inert, synthetic, biodegradable implants or autologous tissue transplantation. However, the potential of using autologous adult stem cells derived from fat tissue is quickly becoming a clinical reality. The possibility of using an abundant source of extraneous tissue as a soft tissue implant has significant implications for plastic and reconstructive surgeons. This strategy would be particularly useful after tumor removal or trauma. The ability of adult stem cells derived from adipose tissue (termed adipose-derived stem cell) to proliferate and differentiate in vivo or in vitro is actively being studied owing to the potential implementation in reconstructive surgery. This review describes innovative research strategies and discusses the first clinical studies involving adipose-derived stem cells as a motif for soft tissue reconstruction.

Freezing adipose tissue grafts may damage their ability to integrate into the host

In this study, the effect of freezing on the morphology, viability, and VEGF synthesis of human adipose tissue grafts is examined. Currently, storage of adipose grafts involves freezing in simple saline solutions. However, the effect of freezing on the morphology and function of adipose tissue remains unclear. As a result, this study attempts to determine whether freezing adipose grafts should be considered prior to soft-tissue augmentation. In this study, the freezing of adipose grafts in saline for only 24 hr resulted in morphological changes in vivo and affected their ability to synthesize VEGF. The use of a simple cryopreservation medium containing sucrose appeared to maintain VEGF synthetic levels by the grafts and improved both their morphology and retention in vivo. However, the benefits of this cryopreservation medium were directly linked to storage time as long-term storage did not result in any noticeable benefit to graft retention. Finally, as an alternative to freezing, adipose grafts were combined with human adipose-derived stem cells (ASCs) to determine if their presence could enhance in vivo graft structure. The presence of ASCs did appear to improve graft structure in vivo over the short term and was also capable of improving tissue morphology when combined with grafts frozen in PBS. In conclusion, the successful use of adipose grafts may require a closer examination of the graft's storage conditions and time. Specifically, it now appears that the practice of freezing in saline may not be advisable if graft viability, activity, and structure are to be maintained in vivo.