Aesthetic Applications of Brava-Assisted Megavolume Fat Grafting to the Breasts: A 9-Year, 476-Patient, Multicenter Experience

The Impact of Recipient Site External Expansion in Fat Grafting Surgical Outcomes

Background:

The fat grafting process includes the 4 phases of tissue harvesting, processing, recipient-site preparation, and reinjection. Among them, the preparation of the recipient site has never been exhaustively reviewed. We aim to provide a comprehensive overview of the methods to prepare the recipient site through external expansion with the resulting outcomes.

Methods:

PubMed/Medline database was searched for studies on fat grafting recipient site preparation by applying the following algorithm: ((fat grafting) OR (lipofilling) OR (lipograft) AND (recipient site)). A priori criteria were used to review the resulting articles and identify those dealing with external expansion.

Results:

Fourteen studies published from 2008 through 2016 met inclusion criteria (4 case reports, 6 retrospective, and 4 prospective studies), representing 1,274 treated patients. Two devices for preexpansion were used with different protocols: BRAVA system and Kiwi VAC-6000M with a PalmPump. The 13 studies that applied the BRAVA system reported large fat volume transplantation to the breast (average > 200 cc). The most common complications were localized edema (14.2%), temporary bruising, and superficial skin blisters (11.3%), while the most serious was pneumothorax (0.5%). The majority of the studies reported enhancement of fat graft survival, which ranged between 53% and 82% at 6 months to 1 year follow-up, and high satisfaction of patients and surgeon.

Conclusions:

External expansion and fat grafting is a promising technique for breast reconstruction and augmentation. However, due to the overall low level of evidence of the available studies, further research is needed to validate the procedure.

Recent Advances on the Application of Negative Pressure External Volume Expansion in Breast Plastic Surgery

BACKGROUND

External volume expansion (EVE) has been effectively applied as an assistance to fat transplantation on breast plastic surgery. Many indicators and refinements have been made in clinical practice; meanwhile, the related mechanism and more optimized preclinical model also have been explored in experimental studies.

METHODS

A literature search was conducted using PubMed with the keywords: EVE, negative pressure, breast enlargement, breast augmentation, breast reconstruction, breast plastic surgery and breast aesthetic surgery. Studies dealing with the clinical and preclinical aspects of the subject and also in vitro experiments related to a certain period of negative pressure and adipose-derived cells were selected, and those only focused on negative pressure were excluded.

RESULTS

The indications, contraindications, complications and treatments of EVE in clinical practice were summarized. The experimental studies were mainly classified into two groups (mechanical and translational) according to their contents. Mechanical studies were further divided into inference experimental validation phase studies. For the experimental validation phase, EVE was verified to promote angiogenesis, while it still remained controversial whether it would enhance adipogenesis and cell proliferation.

CONCLUSION

Clinically, our experience is on the stage of exploration, and there is a lack of standardized guidelines on its clinical application. Experimentally, the previous studies showed some subtly different views on the functional mechanisms. However, it is not enough to regulate the clinical practice yet. Therefore, related basic studies and long-term clinical follow-up are needed.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Soft Tissue Reconstruction

Autologous fat transplantation has revolutionized soft tissue reconstruction, but conventional methods remain unpredictable as graft resorption rates are high due to lack of vascularization. The advent of adipose-derived stem cells (ASCs) has led to improvement of fat grafting outcomes, in part to their ability to undergo facile differentiation into adipose tissue, their angiogenic properties, and their ability to express and secrete multiple growth factors. This chapter discusses the isolation and characterization of human ASCs, its expansion in vitro, and relevant in vivo models for adipose tissue engineering.

Moderate intermittent negative pressure increases invasiveness of MDA-MB-231 triple negative breast cancer cells

BACKGROUND

To investigate the effect moderate intermittent negative pressure breast reconstructive model exerts on human triple negative breast cancer cell (TNBC) invasion and explore the related mechanism.

METHODS

The human TNBC cell line MDA-MB-231 was used. Cells in external volume expansion (EVE) group were exposed to an intermittent -25 mmHg for 12 h; the pressure for non-EVE group was constantly 0 mmHg. In vivo, MDA-MB-231 cell suspensions were injected subcutaneously into dorsal skin of nude mice (n = 27 mice/group). Tumors on mice in EVE group received -25 mmHg suction 3 h/day; while mice in non-EVE group were under normal pressure. Cell invasion assay, ELISA, RT-PCR, western blot analysis and immunohistochemistry were used to evaluate the inflammation, epithelial-mesenchymal transition (EMT) and angiogenesis between the two groups in both vitro and vivo experiments.

RESULTS

MDA-MB-231 cells in the EVE group were more invasive and had higher expressions of IL-8 (30.02 ± 10.44 pg/ml vs. 18.82 ± 9.26 pg/ml, P < 0.05) and TNF-α (20.59 ± 4.72 pg/ml vs. 14.10 ± 3.36 pg/ml, P < 0.05) than the non-EVE group. Grafted MDA-MB-231 tumors in EVE group showed a more obvious epithelial-mesenchymal transition at 2 week and better angiogenesis at 2 and 4 week, respectively.

CONCLUSION

Moderate intermittent negative pressure induces MDA-MB-231 cells to be more invasive. Future studies should figure out other effects this intervention may bring. Clinical studies should also be conducted to further evaluate its safety and optimize the clinical model.

Fat Grafting to the Breast: Clinical Applications and Outcomes for Reconstructive Surgery

This article is a review of fat grafting for breast reconstruction. The use of small volume fat grafting for the correction of step-off deformities, intrinsic deformities, and extrinsic deformities of the breast, and the uses of large volume fat grafting for total breast reconstruction, correction of implant complications with simultaneous implant exchange with fat, and correction of noncancer chest wall deformities is reviewed. Cancer monitoring and the risks of cancer recurrence following fat-grafting to the breast is also reviewed.

'Reverse expansion': A new technique of breast reconstruction with autologous tissue

The treatment for breast cancer is sometimes long and requires a multidisciplinary approach. In 2010, in our centre, we began to perform fat grafting for breast reconstruction using the so-called 'reverse expansion' technique. This consists of the insertion of a skin expander during mastectomy, in its expansion and then in its gradual deflation in the surgical theatre during fat grafting. We performed a complete breast reconstruction in 57 patients by reverse expansion. We harvested fat from the fat excess areas using a normal liposuction cannula. From each patient, an average of 640 ccs of was collected and then centrifuged in a 4000-rpm centrifuge for 3 min. The obtained adipocytes were then injected in the operated breast using a normal lipofilling cannula. We injected an average of 318.05 ccs of adipocytes for each patient each time. The average number of sessions per patient was 3.6. Reverse expansion can be a safe and effective technique for breast reconstruction in all the breast cancer patients.

The Selective Centrifugation Ensures a Better In Vitro Isolation of ASCs and Restores a Soft Tissue Regeneration In Vivo

Autologous fat grafting procedures in plastic surgery have been extensively used to reinforce soft tissue in congenital or acquired tissue impairments. With this background, the aim of this study is firstly to examine the impact of a selective centrifugation on existing adipose stem cells (ASCs) in terms of stemness profile maintenance and, secondly, to investigate the effect of restoring volume in reconstruction on patients affected by soft tissue damage. After centrifugation, the fat graft products were separated into two layers and subsequently examined in vitro for the expression of CD34, CD90, CD117, CD105, CD29, CD31, CD44, CD73, CD133, CD14 and CD45 markers by flow cytometry and gene expression analyses were performed for Sox2, WNT3A, END, CD44, FUT4, COLL1, CTNNB1, hbEGF, KRTLG, MMP2 and VIM genes. The results showed that in the middle-high density (MHD) layer there was a peak concentration of ASCs, compared to another layer obtained after centrifugation. Research carried out on patients under treatment for soft tissue regeneration using cells obtained from MHD layer selection will be fundamental in comparative analysis. These studies will lead to an adequate standardization of outcomes, provided that treatment is performed through cell selection. Therefore, a unique procedure in tissue reconstruction and regeneration through fat grafting is presented here.

Evidence-Based Scar Management: How to Improve Results with Technique and Technology

BACKGROUND

Scars represent the visible sequelae of trauma, injury, burn, or surgery. They may induce distress in the patient because of their aesthetically unpleasant appearance, especially if they are excessively raised, depressed, wide, or erythematous. They may also cause the patient symptoms of pain, tightness, and pruritus. Numerous products are marketed for scar prevention or improvement, but their efficacy is unclear.

METHODS

A literature review of high-level studies analyzing methods to prevent or improve hypertrophic scars, keloids, and striae distensae was performed. The evidence from these articles was analyzed to generate recommendations. Each intervention's effectiveness at preventing or reducing scars was rated as none, low, or high, depending on the strength of the evidence for that intervention.

RESULTS

For the prevention of hypertrophic scars, silicone, tension reduction, and wound edge eversion seem to have high efficacy, whereas onion extract, pulsed-dye laser, pressure garments, and scar massage have low efficacy. For the treatment of existing hypertrophic scars, silicone, pulsed-dye laser, CO2 laser, corticosteroids, 5-fluorouracil, bleomycin, and scar massage have high efficacy, whereas onion extract and fat grafting seem to have low efficacy. For keloid scars, effective adjuncts to excision include corticosteroids, mitomycin C, bleomycin, and radiation therapy. No intervention seems to have significant efficacy in the prevention or treatment of striae distensae.

CONCLUSION

Although scars can never be completely eliminated in an adult, this article presents the most commonly used, evidence-based methods to improve the quality and symptoms of hypertrophic scars, as well as keloid scars and striae distensae.

Cell assisted lipotransfer in breast augmentation and reconstruction: A systematic review of safety, efficacy, use of patient reported outcomes and study quality

BACKGROUND

Cell assisted lipotransfer serves as a novel technique for both breast reconstruction and breast augmentation. This systematic review assesses the efficacy, safety and use of patient reported outcome measures in studies involving cell assisted lipotransfer. We also carry out an objective assessment of study quality focussing on recruitment, follow-up and provide an up-to-date clinical trial landscaping analysis.

METHODS

Key electronic databases were searched according to PRISMA guidelines and pre-defined inclusion and exclusion criteria. Two independent reviewers examined the retrieved publications and performed data extraction.

RESULTS

3980 publications were identified. Following screening, 11 studies were included for full review, representing a total of 336 patients with a follow-up time ranging from six to 42 months. A degree of variation was noted in graft retention and reported satisfaction levels, although there were only three comparative studies with conflicting results. Complications occurred at a rate of 37%. Additionally, there was a paucity of objective outcomes assessments (e.g. 3D assessment modalities or validated patient reported outcome measures) in the selected studies.

CONCLUSIONS

Cell assisted lipotransfer is a surgical technique that is currently employed sparingly within the plastic & reconstructive surgery community. Presently, further technical and outcome standardization is required, in addition to rigorous randomized controlled trials and supporting long-term follow-up data to better determine procedural safety and efficacy. Routine use of more objective outcome measures, particularly 3D assessments and validated patient reported outcome measures, will also help facilitate wider clinical adoption and establish procedural utility.

Autologous Fat Grafting in Cosmetic Breast Augmentation: A Systematic Review on Radiological Safety, Complications, Volume Retention, and Patient/Surgeon Satisfaction

BACKGROUND

Autologous fat grafting (AFG) is increasingly used in cosmetic surgery. However, its efficacy and safety are still ambiguous. Both a comprehensive overview and recapitulation of the relevant literature provide current evidence on the efficacy and outcomes of AFG in cosmetic breast surgery.

OBJECTIVES

This review provides an up-to-date overview of the literature on AFG in cosmetic breast augmentation.

METHODS

A systematic review of the literature on AFG used for cosmetic breast augmentation was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. This study included selected studies that were published between January 1996 and February 2016 and reported on 10 patients or more who had a minimal mean follow-up period of 1 year.

RESULTS

In this study, 22 articles that reported on 3565 patients with follow-up periods ranging from 12 to 136 months were included. A complication rate of 17.2% (95% CI 15.9-18.5) was seen. Indurations were the most frequent complication (33.3%, 95% CI 20.4-46.3), followed by persistent pain (25%, 95% CI 0.5-49.5), and hematoma (16.4%, 95% CI 14.5-18.4). Mammograms revealed micro-calcifications (9.0%, 95% CI 6.4-11.5) and macro-calcifications (7.0%, 95% CI 3.8-10.2). The mean volume retention was 62.4% (range, 44.7-82.6%), with a satisfaction rate of 92% in patients and 89% in surgeons.

CONCLUSIONS

AFG is a promising method in achieving autologous cosmetic breast augmentation with satisfactory volume retention and satisfaction rates in eight and six studies, respectively. Complications and radiological findings are comparable to those after implant augmentation. Future studies should focus on cancer occurrence and detection to further substantiate AFG safety. In addition, grafting methods and the use of auxiliary procedures to identify factors leading to better outcomes in terms of volume retention should be investigated. Finally, objective questionnaires are needed to represent patient satisfaction.

LEVEL OF EVIDENCE

3 Therapeutic.

The Safety, Effectiveness, and Efficiency of Autologous Fat Grafting in Breast Surgery

Background:

For years, the safety and effectiveness of autologous fat grafting (AFG) for breast reconstruction have been in question, with particular concern over fat necrosis, calcifications, cyst formation, and interfering with the detection of breast cancer. However, increasing evidence suggests that the complication rates and clinical results are generally acceptable to both clinicians and patients. The emerging challenge is the numerous AFG techniques and systems, where there are limited knowledge and data. The objective of this study was to conduct a literature review that focuses on the safety, effectiveness, and efficiency of various AFG techniques as applied to the breast.

Methods:

A PubMed search using terms related to AFG was performed over a 5-year period (April 1, 2010–April 30, 2015). Original articles focused on AFG to the breast, with outcomes on safety, effectiveness, and efficiency, were included.

Results:

Five hundred ninety-eight articles were identified with 36 articles included (n = 4306 patients). Satisfaction rates were high although the prevalence of complications was low—similar to previous findings. Seven studies reported average operating room time with an overall mean of 125 minutes (range: 40–210). The mean volume of fat harvested was 558 mL (range: 120–1299), and fat injected was 145 mL (range: 20–607). A positive association between injection volume and operating time was observed.

Conclusions:

This review validates previous findings on the safety and effectiveness of AFG to the breast and highlights its efficiency. The efficiency data available, although limited, suggest that there is an opportunity to achieve time and cost savings while not sacrificing safety and effectiveness.

An Overview of Fat Grafting

The use of autologous fat grafting for a wide variety of clinical applications has increased dramatically over the past few decades. The article provides an overview of the technique, a historic background, and briefly explores some of the current ways in which fat grafting is being used in plastic surgery.

Autologous fat grafting in onco-plastic breast reconstruction: A systematic review on oncological and radiological safety, complications, volume retention and patient/surgeon satisfaction

OBJECTIVE

This study presents an up-to-date overview of the literature on autologous fat grafting (AFG) in onco-plastic breast reconstruction, with respect to complications, oncological and radiological safety, volume retention and patient/surgeon satisfaction.

BACKGROUND

Although AFG is increasingly being applied in onco-plastic breast reconstruction, a comprehensive overview of the available evidence for this procedure is still lacking.

METHODS

A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement was conducted. Case series, cohort studies and randomized controlled trials (RCTs) reporting on relevant outcomes of breast reconstruction with supplemental AFG were included.

RESULTS

In total, 43 studies were included reporting on 6260 patients with a follow-up period ranging from 12 to 136 months. The average locoregional and distant oncological recurrence rates after breast reconstruction with AFG were 2.5% (95% confidence interval (CI) 1.7-3.7) and 2.0% (95% CI 1.1-3.5), respectively. Fewer cysts and calcifications were seen on radiological images for this procedure than for other types of breast surgery. However, more biopsies were performed based on radiological findings (3.7% vs. 1.6%), and more cases of fat necrosis (9.0% vs 4.7%) were seen after treatment with AFG. The total complication rate of 8.4% (95% CI 7.6-9.1) is lower than those reported following other reconstructive breast procedures. The mean volume retention was 76.8% (range 44.7-82.6%) with a satisfaction rate of 93.4% for patients and 90.1% for surgeons.

CONCLUSIONS

AFG in breast reconstruction is a promising technique. Safety is not compromised as cancer recurrence and complications are not observed. Whether AFG interferes with radiological follow-up remains to be elucidated. Randomized trials with sound methodology are needed to confirm these conclusions.

Autologous Fat Grafting in the Breast: Critical Points and Technique Improvements

BACKGROUND

Breast augmentation or reconstruction is a major challenge in esthetic and reconstructive surgery. While autologous fat grafting (AFG) provides a natural filler and seems easy to harvest, AFG in breast surgery is still problematic especially due to the high resorption rate associated with megavolume transfer. Despite this pending issue, there is growing interest in this method, which is becoming more and more widespread, as can be seen by the recent increase in the number of clinical studies. This review aims to highlight recent knowledge in the technique of AFG to the breast and recent refined procedures to improve fat viability and long-term success of the graft.

METHODS

Clinical publications and trials of AFG to the breast from the past 5 years were examined. Attention was focused on the different AFG steps and the clinical outcomes, in order to highlight the strengths and weaknesses of the available protocols.

RESULTS

Recent studies have concentrated on new techniques to improve fat viability and graft intake. However, all of these studies use different protocols at each step of the procedure. Furthermore, results may vary depending on the technique used for fat harvesting and processing.

CONCLUSION

This review points out the recent advances in breast AFG techniques and their associated outcomes and complications. The bibliography has been carefully examined to reach a consensus so that recommendations could be made for each step of the technique with the aim of improving graft viability and long-term volume maintenance.

Shaping of the Unaffected Breast with Brava-Assisted Autologous Fat Grafting to Obtain Symmetry after Breast Reconstruction

BACKGROUND

In breast reconstruction, symmetry is a vital issue. However, when the original breast is unusually shaped or the patient desires augmentation at the time of reconstruction, obtaining symmetrical breasts becomes difficult.

OBJECTIVES

The authors performed shaping of unaffected breasts by Brava-assisted autologous fat grafting to enhance breast symmetry, and evaluated the clinical results to validate this new approach.

METHODS

Brava-assisted autologous fat grafting was performed to the unaffected breasts of 12 patients who had undergone unilateral breast reconstruction. The procedure was used for augmentation in six patients and to correct ptosis, volume, and tuberous breast deformity in three, two, and one patient, respectively. Clinical outcomes were assessed in all 12 patients.

RESULTS

All patients could complete fat grafting within two sessions (one session in nine patients and two sessions in three patients). The mean volume of grafted fat per session was 211 cc in all patients. The mean retention rate of grafted fat was 58.9% in the 10 patients for whom the retention rate could be calculated using preoperative and postoperative magnetic resonance imaging (MRI). Postoperative MRI revealed small benign foci in two patients (16.7%), which were not palpable and did not become a clinical problem. A postoperative mammography revealed a small agglutinate calcification in one patient, which was determined to be benign through biopsy.

CONCLUSIONS

Shaping the unaffected breast by autologous fat grafting combined with Brava is predictable, effective, and feasible as an aesthetic adjunct to unilateral breast reconstruction to achieve breast symmetry.

LEVEL OF EVIDENCE

4 Therapeutic.

Breast Reconstruction with Delayed Fat-Graft-Augmented DIEP Flap in Patients with Insufficient Donor-Site Volume

BACKGROUND

Microvascular reconstruction provides natural, lasting breasts that can be integrated easily into body image but most thin patients are often not ideal candidates because of inadequate donor-site volume. The purpose of this study was to present our experience in delayed augmented DIEP flaps with large fat-volume transfer.

METHODS

From 2010 to 2014, 20 consecutive patients were prospectively enrolled for delayed fat-graft-augmented DIEP flaps (active group, AG) and matched with a control group (CG) submitted to the same procedure without fat-injection. Patient's age, mastectomy and flap weight, number of take-backs to the theater for secondary procedures, total treatment period (TTP), and complications were collected and analyzed. Patient and surgeon surveys rated aesthetic outcomes. Continuous and categorical variables were analyzed using student t test and Kruskal-Wallis test, respectively. A value of p ≤ 0.05 was considered statistically significant.

RESULTS

The groups did not differ in age and mastectomy weight (p > 0.05). The AG had a smaller BMI and flap weight (p < 0.05). Comparison of the mean number of take-backs (1.5 in AG vs. 1.4 in CG) and mean TTP (8.6 months in AG vs. 8.9 months in CG) did not show a significant difference (p > 0.05) between groups. Volume, upper/lower-pole shapes, projection, breast mound placement, IMF, symmetry, overall appearance, and general satisfaction sub-items obtained high-score evaluation without a significant difference between groups (p > 0.05).

CONCLUSION

Delayed fat-graft-augmented DIEP flaps can be offered to patients with insufficient donor-site volume and medium/large breasts. In comparison with the same technique without fat grafting, no additional take-backs and no prolonged TTP were required to achieve pleasing aesthetic results.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Autologous fat grafting for cosmetic breast augmentation: a systematic review

BACKGROUND

Breast augmentation is one of the most popular aesthetic surgical procedures. The only potential alternative is autologous fat grafting (AFG), which is not new in principle. This procedure has been used on native breasts since 2009, following the recommendations of some learned societies.

OBJECTIVES

We performed a systematic review to determine the current worldwide status of fat grafting for aesthetic breast augmentation.

METHODS

A systematic review of the literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis criteria was conducted using the PubMed, EmBASE, and Cochrane library databases. This protocol was registered at the National Institute for Health Research, Prospective Register of Systematic Reviews.

RESULTS

A total of 42 articles published between 1987 and July 2014 were included. Most of the studies had a low level of evidence, with only one level 2 study, published by Spear (2014), a prospective cohort study which included 10 patients. The publications were from North America, Europe, and Asia. The indications were aesthetic augmentation (92.4%) and congenital malformation (7.6%). Two cases of cancer were reported among the 2023 patients included (0.09%), with a mean follow-up of 22 months, although the follow-up was insufficient for medium- and long-term cancer diagnoses.

CONCLUSIONS

AFG seems to be a major tool in this field, but we must remain cautious about its systematization for this indication. Preoperative patient selection is essential but underreported. AFG appears particularly relevant in breast malformations. We believe that this method should be practiced within the scope of a national or international registry with proper follow-up of patients.

Delayed total breast reconstruction with brava

Several surgical procedures exist in regard to reconstruction of the breast after mastectomy. The use of Brava a vacuum-based external soft-tissue expansion system in combination with fat transplantation is a less documented but viable option in treating patients after mastectomy. We share our experience in treating a 57-year-old patient with mastectomy, describing the complications and pitfalls we experienced when using the Brava system in combination with fat transplantation.

Breast lipofilling: a review of current practice

Lipofilling is a reconstructive and aesthetic technique that has recently grown in popularity and is increasingly being used in breast surgery. Previous concerns had been raised regarding its safety when used for remodelling and reconstruction of the breast; however, these concerns have since been dismissed. Over the subsequent two decades, little evidence has been found to support these early theoretical concerns, and growing numbers of proponents of the procedure are confident in its safety. Many developments and refinements in the technique have taken place in recent years, and several studies have been published regarding the safety of lipofilling in the breast. We reviewed the current literature regarding the use of different lipofilling techniques as well as the current evidence regarding the oncological safety of the procedure in patients seeking aesthetic breast enhancement and in patients requiring reconstruction after treatment for breast cancer.

[Regenerative therapy approaches in plastic surgery]

BACKGROUND

The regeneration of tissue lost due to trauma or disease is considered as being ideal for reconstruction with respect to repair in which a donor defect arises in a different part of the body. Through a better understanding of the cellular and molecular mechanisms of healing, possibilities for regenerative therapies have been developed in recent years.

OBJECTIVES

To give an exemplary representation of current regenerative therapy approaches and their effect and clinical application.

MATERIAL AND METHODS

The PubMed database was searched for different regenerative approaches in plastic surgery and various methods are presented in this article.

RESULTS

Cell-based approaches, in which autologous mesenchymal stem cells from adipose tissue are preferably used, led to excellent healing results with minimal donor site morbidity. Likewise, growth factor-based approaches or the use of platelet-rich plasma achieve very good results in the field of wound and bone healing.

DISCUSSION

By using different cells or molecules and thus taking advantage of biological mechanisms, the regenerative capabilities of adult organisms could be improved. Many methods have already been implemented in clinical practice, not only in reconstructive but also in aesthetic surgery. However, the success should not conceal the potential risk that is inherent in both cell and growth factor-based approaches. Until long-term experiences of such therapies have been acquired, they should be used cautiously.

Fat Graft Viability in the Subcutaneous Plane versus the Local Fat Pad

Background:

Fat grafting has been increasingly utilized in both aesthetic and reconstructive surgical procedures, yet the basic scientific understanding of fat grafting has lagged behind the pace of clinical innovation and utilization. This lack of basic scientific understanding has perhaps manifested itself in the wide range of graft viability reported across the literature. This study attempts to further the underlying mechanisms of fat graft take and viability through the comparison of the subcutaneous plane and the local fat pad in athymic rats.

Methods:

Lipoaspirate from a consenting patient was grafted into 2 locations in the subcutaneous plane and into the 2 inguinal fat pads in each of 4 athymic rats. Specimens were then collected after 47 days, and immunohistochemistry was utilized to determine angiogenesis in the fat grafts as a measure of fat graft take. Data were analyzed using the Student’s t test and analysis of variance followed by multiple comparisons.

Results:

There was no statistically significant difference (P = 0.2913) between the inguinal fat pad and the subcutaneous plane when measuring neovascularization. Analysis of variance comparing the graft locations also indicated no statistically significant difference when comparing each of the rats.

Conclusions:

Investigation into fat graft injection location indicates that there is no statistically significant difference in angiogenesis signals between the subcutaneous plane and the local fat pad in the athymic rat model. Further research should aim to continue to close the gap between clinical practice and basic scientific understanding of fat grafting.

Total breast reconstruction using autologous fat grafting following nipple-sparing mastectomy in irradiated and non-irradiated patients

BACKGROUND

Although autologous microvascular reconstruction following nipple-sparing mastectomy (NSM) is considered one of the best reconstructive choices, this procedure cannot be offered to all patients. The aim of this study was to define a fat grafting protocol for successful reconstruction following NSM and to assess its reliability in irradiated and non-irradiated patients.

MATERIALS AND METHODS

Twenty-one patients were prospectively enrolled and stratified in Group-A (11 non-irradiated) and Group-B (10 irradiated) NSMs comparing clinical and aesthetic outcomes. A fat grafting protocol was used to standardize the procedure. Continuous and categorical variables were analysed using the Student t test and the Kruskal-Wallis test, respectively. A value of p ≤ 0.05 was considered statistically significant.

RESULTS

The groups were homogeneous in terms of demographics (p > 0.05), while number of sessions, mean volume of the first two treatments, and overall injected volume showed significant differences (p < 0.001; p < 0.001; p = 0.002). Volume, shape, position of the breast mound, IMF and scar location subscales obtained high score evaluations without a significant difference between the groups (p > 0.05), whereas the skin texture subscale showed a lower score evaluation in Group-B than in Group-A (p = 0.001). Although a significant difference for total subscales was in favour of Group-A (p = 0.001), the global score had a high rate evaluation in both groups (p = 0.132). Inter-rater reliability showed substantial agreement among all categories, total and global scores.

CONCLUSIONS

To the best of our knowledge, this is the first prospective series of fat transfer reconstructions following NSM using a systematic approach. Although further studies are required, it may be considered an effective option whenever flap reconstruction cannot be performed.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Diffusion and perfusion: the keys to fat grafting

BACKGROUND

Fat grafting is now widely used in plastic surgery. Long-term graft retention can be unpredictable. Fat grafts must obtain oxygen via diffusion until neovascularization occurs, so oxygen delivery may be the overarching variable in graft retention.

METHODS

We studied the peer-reviewed literature to determine which aspects of a fat graft and the microenvironment surrounding a fat graft affect oxygen delivery and created 3 models relating distinct variables to oxygen delivery and graft retention.

RESULTS

Our models confirm that thin microribbons of fat maximize oxygen transport when injected into a large, compliant, well-vascularized recipient site. The "Microribbon Model" predicts that, in a typical human, fat injections larger than 0.16 cm in radius will have a region of central necrosis. Our "Fluid Accommodation Model" predicts that once grafted tissues approach a critical interstitial fluid pressure of 9 mm Hg, any additional fluid will drastically increase interstitial fluid pressure and reduce capillary perfusion and oxygen delivery. Our "External Volume Expansion Effect Model" predicts the effect of vascular changes induced by preoperative external volume expansion that allow for greater volumes of fat to be successfully grafted.

CONCLUSIONS

These models confirm that initial fat grafting survival is limited by oxygen diffusion. Preoperative expansion increases oxygen diffusion capacity allowing for additional graft retention. These models provide a scientific framework for testing the current fat grafting theories.