Long-term survival of free fat grafts in muscle: an experimental study in rats

The effect of host tissue and radiation on fat-graft survival: A comparative experimental study

Because lipofilling is often associated with various reconstructive procedures, especially breast reconstructions, improving fat-graft retention remains a major concern for plastic surgeons. We conducted an experimental protocol in a rat model simulating an autologous breast reconstruction method using the fat-augmented latissimus dorsi myocutaneous (LDM) flap. This study aimed to compare the survival rates of autologous adipocytes when injected subcutaneously and intramuscularly and to evaluate the role of recipient host tissue, volume of the injected fat, and postoperative radiation on fat-graft retention. Thirty rats were divided into five groups (A, B, C, D, and E), of six rats each. All animals underwent a pedicled LDM flap transfer to the anterior thoracic wall, and different volumes of autologous fat were injected into three recipient areas, namely, the pectoralis major and latissimus dorsi muscles and the subcutaneous tissue of the flap's skin island, as follows: 1 mL of fat was injected in total in group A, 2 mL in groups B and D, and 5 mL in group C. Group D animals received postoperative radiation (24 Gy), whereas group E animals (controls) did not undergo any fat grafting procedure. Eight weeks after surgery, adipocyte survival was assessed in all groups using histological and immunochemistry techniques. The results showed that the pectoralis major muscle was the substrate with the highest adipocyte survival rates, which were proportional to the amount of fat injected, followed by the latissimus dorsi muscle and the subcutaneous tissue. Increased volumes of transplanted fat into the subcutaneous tissue did not correspond to increased adipocyte survival. Irradiation of host tissues resulted in a statistically significant decrease in surviving adipocytes in all three recipient sites (p<0.001). Our study strongly suggests that muscle ensures optimal fat-graft retention, whereas postoperative radiation negatively affects adipocyte survival following fat transplantation.

Primary lipofilling as an adjunct in transverse upper gracilis flap breast reconstruction

In many centres, the myocutaneous transverse upper gracilis (TUG) flap represents an alternative choice in autologous breast reconstruction when abdominal tissue is unavailable. However, a single TUG flap may be volume deficient, particularly in the upper pole. We describe the application of simultaneous lipofilling to the pectoralis major muscle at the index procedure and present our decision-making algorithm, technique and outcomes. A retrospective review of all TUG flaps between January 2011 and May 2021 was conducted. Patient demographics, volume of primary and any subsequent fat grafting and complications were recorded. A total of 183 patients (242 TUG flaps) were included in this study. Of these; 130 patients were reconstructed with single TUG flaps, 16 patients received a single TUG flap with immediate lipofilling, and 37 patients underwent stacked, double TUG flap reconstructions. Of the 242 flaps, there were 2 flap losses (<1%), neither of which occurred in the immediate lipofilling cohort. Among the 130 single TUG patients, 28 (21.5%) required a cumulative total of 40, and a mean of 1.4, secondary lipofilling procedures. The immediate lipofilling patients were injected with a mean of 42 ml fat (range: 20-80 ml). In this group, only 2 of 16 patients required secondary lipofilling. The mean follow-up was 67 months (17-141). Primary lipofilling may reduce the need for secondary revisional procedures and appears safe at the index operation, adds little operative time and has negligible donor site morbidity. In patients where a second (stacked) flap would add unnecessary volume and complexity, it can be considered a useful adjunct.

Comparing the safety profiles of implants and autologous fat grafting in gluteal augmentation: A systematic review

Gluteal augmentation has become a popular esthetic procedure since its inception. The main methods are augmentation using implants or autologous fat grafting, which is the harvesting and grafting of patients' own fat tissue. The last review comparing the safety of these methods was written 7 years ago, which warrants the writing of a new one. PubMed, Cochrane, and Medline were searched for studies focusing on the methods of gluteal augmentation listed previously. Five search terms were used and 15 studies fulfilled the criteria. The data were cataloged according to the method described and outcomes compared. Seven articles focused on gluteal implants and another seven assessed autologous fat grafting, whereas one detailed both. The most common complications in 524 implant procedures were wound dehiscence (9.16%), excessive implant palpability (5.92%), and seroma (3.82%), with an overall complication rate of 25%. The most common complications in 1788 gluteal fat augmentation procedures were seroma (6.9%), infection (3.0%), and transient sciatic paresthesia (1.0%), with an overall complication rate of 13%. Several articles listed satisfaction figures, but these were not assessed because this article was not powered to assess this outcome. Overall, gluteal augmentation using autologous fat grafting leads to fewer postoperative complications than implants and allows greater contouring of the buttocks and the surrounding areas. However, it can also be a far more dangerous procedure if certain recommendations are not followed.

Intramuscular Posterior Thigh Volumization: An Aesthetic and Harmonious Transition to the Gluteal Region (Hv-FAT)

The gluteal region remains the preferred site for fat grafting. However, the transition from the gluteal region to the thighs has not been well studied. This study aimed to describe an echographic guidance hamstring volumization procedure (Hv-FAT) as a complement to body contouring surgery.

Clinical application of endoscopic soft palate augmentation in the treatment of velopharyngeal insufficiency

Velopharyngeal structure augmentation with the injection of autologous fat tissue into the nasal mucosa of the soft palate has been reported previously. However, as the injection points in the velopharyngeal space cannot be observed directly, these injections may be difficult to perform accurately. This report describes a new endoscope-assisted approach in which the materials for velopharyngeal structure augmentation are administered while observing the injection points directly, also enabling adjustment of the amount of material injected. A case series of five patients aged 8-16 years who underwent endoscopic soft palate augmentation under general anaesthesia is reported. Autologous fat tissue was injected into the nasal mucosa of the soft palate using a needle-type device of an endoscope, and the effects of the treatment were evaluated. The injections were performed successfully, and the velopharyngeal function was improved. This new technique of endoscopy-assisted augmentation was useful for the treatment of velopharyngeal insufficiency.

Viability of Fat Cells in Frozen Fat Tissue in Relation to Thawing Technique

Damage of frozen fat, which will be used for retransplantation, is inevitable. Reuse of frozen fat requires a thawing process. No standardized method has yet been established for thawing frozen fat.

Echo-guided Lower-back Sculpture and Volumization as a Complement to High-definition Liposuction (XPINE-FAT)

Background:

Knowledge about lower-back aesthetics is very limited, especially regarding surgical techniques that improve its appearance. Thus, this study aimed to describe a high-definition liposuction technique with intramuscular grafting of erector spinae muscles (longissimus).

Methods:

A total of 15 female patients 25–48 years of age were recruited between November 2021 and January 2022, who underwent body contouring surgery and subsequently underwent a low-back lipodefinition and echo-guided intramuscular erector spinae (longissimus) fat graft to complement the procedure. As part of the study, measurements were performed before surgery and in the immediate postoperative period. The data were stored in a database and analyzed with the SPSS Version 25 statistical software.

Results:

The patients’ ages ranged from 25 to 48 years (mean: 37 years), with a body mass index of 18.6–29.3 (mean: 25.5). The surgical times ranged between 1 and 8 hours (mean: 3.73 hours); hospitalization times were 0.7–1 days (mean: 0.940 days). Lipograft was performed on the erector spinae muscles (longissimus), the right one with a range of 20–60 cm³ (mean: 43.33 cm³) and percentage increase of 65.3% (P < 0.0001). Regarding the left erector, similar volumes between 20 and 60 cm³ (mean: 44.67 cm³) were grafted with a percentage increase of 66.4% (P < 0.0001).

Conclusions:

XPINE-FAT is a safe technique that allows an increase in the immediate intramuscular thickness of the erector spinae muscles (longissimus). We observed no adverse events during the study.

Effects of Temporary and Permanent Muscle Denervation on Fat Graft Retention in the Latissimus Dorsi Muscle: An Experimental Study in Rats

BACKGROUND

In breast reconstruction with a latissimus dorsi flap, immediate fat grafting is useful for increasing flap volume. However, factors such as latissimus dorsi muscle atrophy and fat graft retention affect the volume of the reconstructed breast, and reports are inconsistent regarding treatment of the thoracodorsal nerve. This study examined how thoracodorsal nerve treatment affects the rates of latissimus dorsi flap preservation and fat graft retention using a rat model.

METHODS

Fat harvested from the inguinal region was grafted to the latissimus dorsi muscle elevated as a pedicled muscle flap on the experimental side and to the intact LD muscle on the contralateral side (control). Rats were divided into intact thoracodorsal nerve (Ni), temporary denervation (Ntd), and permanent denervation (Npd) groups (n = 8 each). Fat retention and muscle preservation rates were determined, and histological changes were analyzed postoperatively.

RESULTS

Fat retention rates did not significantly differ between the Ni and Ntd groups. Only the Npd group showed a significant decrease in fat retention rate relative to the control side (p < 0.01). The quality of the grafted fat as reflected by histological parameters was significantly lower, and the viable adipocyte area and muscle fiber preservation rate significantly decreased, in the Npd group compared to the other groups.

CONCLUSIONS

Permanent thoracodorsal nerve denervation resulted in severe muscle atrophy and a significantly decreased fat retention rate. Temporary denervation had no significant benefit, suggesting that preserving the thoracodorsal nerve may be desirable for achieving sufficient volume in latissimus dorsi flap breast reconstruction with immediate fat grafting.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

Surgical Decision Making in Autologous Fat Grafting: An Evidence-Based Review of Techniques to Maximize Fat Survival

Autologous fat grafting is an important tool in plastic surgery and is widely used for a variety of applications, both aesthetic and reconstructive. Despite an ever-increasing list of indications and extensive research over many years into improving outcomes, fat grafting remains plagued by incomplete and often unpredictable graft survival. Decisions made at each stage of surgery can potentially contribute to ultimate success, including donor site selection and preparation, fat harvest, processing, and purification of lipoaspirate, recipient site preparation, and delivery of harvested fat to the recipient site. In this review, we examine the evidence for and against proposed techniques at each stage of fat grafting. Areas of consensus identified include use of larger harvesting and grafting cannulas and slow injection speeds to limit cell damage due to shearing forces, grafting techniques emphasizing dispersion of fat throughout the tissue with avoidance of graft pooling, and minimizing exposure of the lipoaspirate to the environment during processing. Safety considerations include use of blunt-tipped needles or cannulas to avoid inadvertent intravascular injection as well as awareness of cannula position and avoidance of danger zones such as the subgluteal venous plexus. We believe that using the evidence to guide surgical decision-making is the key to maximizing fat grafting success. Level of Evidence: 4.

Impact of Fat Graft Thickness and Harvesting Technique on Adipocyte Viability in a New Porcine Experimental Model: An Immunohistochemical Analysis

BACKGROUND

Autologous fat grafting (AFG) has been employed in surgical practice as a filling method. However, controversies remain on the specifics of this technique. So far, few relevant experimental large animal studies have objectively assessed factors related to AFG integration.

OBJECTIVES

This study utilized an experimental, medium-sized animal model to compare the feasibility of AFG collected employing 2 different techniques with instruments of distinct thicknesses.

METHODS

Twenty minipigs (Sus scropha domesticus) were subjected to AFG harvesting via en bloc resection utilizing 3- (Group I) and 5-mm-diameter (Group II) round punch blades (PBs) and liposuction (LS) with 3- (Group III) and 5-mm-diameter cannulas (Group IV). Both samples were grafted intramuscularly (biceps femoralis). Hematoxylin and eosin staining was employed to identify intact adipocytes, fat necrosis, fibrosis, inflammation, and oil cysts. Immunohistochemical staining (perilipin-A, tumor necrosis factor alfa, and cluster of differentiation number 31) was utilized to quantify the feasibility of adipocytes, tissue necrosis, and neoangiogenesis, respectively.

RESULTS

Hematoxylin and eosin analysis showed that fat necrosis and histiocyte presence were significantly lower in the AFG harvested utilizing a PB than in LS. For perilipin-A, a statistical difference was observed between subgroups I and III (P = 0.001) and I and IV (P = 0.004). Instrument diameter had no effect on graft integration in comparisons between groups II and III (P = 0.059) and II and IV (P = 0.132).

CONCLUSIONS

In this experimental study, fat collected utilizing a PB demonstrated higher adipocyte viability than fat collected with LS. The diameter of the collection instruments, whether PB or LS, had no effect on graft integration.

Shaping an Anatomical Breast Using Extended Latissimus Dorsi Flap and Lipofilling in Immediate Breast Reconstruction

BACKGROUND

Although many attempts have been made to augment the volume of the latissimus dorsi (LD) myocutaneous flap in breast reconstruction, only a few studies on the shaping of the LD flap to achieve a natural native breast have been conducted. We introduce our novel method to reconstruct a naturally shaped breast by combining an extended LD myocutaneous flap with immediate lipofilling.

METHODS

The patients who underwent an immediate unilateral breast reconstruction with an extended LD myocutaneous flap and lipofilling were retrospectively reviewed. The extended LD myocutaneous flap in 180-degree rotation was combined with an immediate lipofilling procedure followed by suturing to reproduce the constant dimensions of a neobreast.

RESULTS

A total of 45 patients with a mean age of 46 years and an average body mass index of 23.1 kg/m were enrolled. The average weight of the mastectomy specimens was 299.0 g. An average 18.8 × 8.7-cm skin paddle within the flap was harvested, and 71.0 mL of fat was injected into the flap. Donor site seroma was found in 9 patients, and no flap or fat necrosis was found.

CONCLUSIONS

Our technique of extended LD muscle flap with lipofilling reproduced breasts with constant dimensions and appropriate width, height, and projection. Shaping the LD muscle flap is not difficult or unpredictable. This is a simple and easy technique to shape the LD flap and will provide surgeons with an additional autologous option for breast reconstruction.

Evaluation and management of facial granuloma caused by various injection materials

BACKGROUND

Various substances are currently being used for cosmetic or postsurgical reconstruction reasons. Injecting of various materials into the face may provoke inflammatory or granulomatous reactions, infection and tissue necrosis. Among these reactions are foreign body granulomas. This study aims to describe the clinical characteristics of and therapeutic approaches used in patients with facial foreign body granulomas caused by the injection of various substances.

METHODS

From 2007 to 2020, a total of 64 patients visited our hospital due to inflammatory signs, palpable masses or surface irregularities. We reviewed patient characteristics, type of injected material, medical history and treatment outcomes. The treatment results were scored with patient satisfaction and statistical analysis of the treatment period was performed.

RESULTS

Most patients underwent conservative treatment followed by surgical treatment because of persistent symptoms; one patient did not require surgery. All patients reported good treatment results and satisfaction. The earlier the surgical treatment was performed, the shorter the treatment period and the higher patient satisfaction scoring.

CONCLUSION

Granulomatous changes to the face are an emerging concern in various cosmetic procedures and surgeries, including fillers, silicone implants and autologous fat injections. Our findings strongly suggest that patient symptoms require accurate diagnosis and surgical treatment.

Safe Composite Calf Augmentation: A Staged Procedure

BACKGROUND

Calf augmentation can be achieved by fat grafting, calf implants, or a combination of both methods (composite augmentation). For safety reasons, it is important to be aware of important calf anatomic features, specific physiologic considerations, and some health conditions that can hinder the outcome of these procedures.

OBJECTIVES

The aim of this study was to present our experience with performing composite calf augmentation, and to describe indications, surgical techniques and safety issues.

METHODS

We retrospectively analyzed 63 patients who had undergone composite calf augmentation for cosmetic and reconstructive surgery in our practice. We reviewed group demographics, complications, and results, and identified all the pitfalls encountered in our cases. Additionally, dissection of the calf regions in fresh cadavers was performed to obtain more accurate anatomy. We also measured intracompartmental pressures before and after calf augmentation with implants in 6 cases to determine pressure changes.

RESULTS

All cases received subfascial implant insertion and fat grafting as a delayed procedure. If there is a need for multiple implants, we recommend a staged procedure. Our study showed high muscle sensitivity to pressure increase after augmentation. Hence, from the standpoint of safety, we advocate subcutaneous fat grafting only. No patients developed compartment syndrome.

CONCLUSIONS

Composite calf augmentation surgery is safe and easy to reproduce, with a short recovery period and a low complication rate when done as a staged procedure and respecting specific anatomic and physiologic calf features.

LEVEL OF EVIDENCE: 4

Update on Nonfacial Fat Transplantation

BACKGROUND

Fat transplantation is becoming increasingly popular for off-face rejuvenation.

OBJECTIVE

To provide an update in the literature of current knowledge and emerging concepts in the use of fat transplantation for nonfacial applications.

MATERIALS AND METHODS

This update includes the potential benefits and risks of using fat transfer techniques on the body.

RESULTS

The current literature and author experiences are provided to help understand this growing field of aesthetic procedures.

CONCLUSIONS

The use of nonfacial fat transplantation is increasing and will become a larger part of aesthetic practices.

Endoscopic soft palate augmentation using injectable materials in dogs to ameliorate velopharyngeal insufficiency

Background

Velopharyngeal structure augmentation methods are used as alternatives to pharyngeal flap operations. Recently, we investigated the sites of velopharyngeal structure augmentation in dogs and reported that the most effective injection location is the soft palate. However, there have been no reports regarding the optimal materials for implantation or injection. In this study, we aimed to investigate the injectable materials used in soft palate augmentation in dogs to ameliorate velopharyngeal insufficiency (VPI).

Methods

Endoscopic soft palate augmentation (ESPA) was performed in dogs using purified sodium hyaluronate, atelocollagen, or autogenic fat tissue. ESPA is an original technique developed by our group, and this is the first report of its performance. Moreover, we assessed the amount of nasal air leakage during inspiration at rest and during expiration under the rebreathing system at 1, 2, 3, 4, 5, and 6 months after injection of these materials.

Results

The amount of nasal air leakage during expiration under the rebreathing system was significantly decreased in all dogs injected with the ESPA materials, but neither apnea nor hypopnea was observed.

Conclusions

We investigated the optimal materials for use in ESPA, such as purified sodium hyaluronate, atelocollagen, or autogenic fat tissue. We found that all of them reduced nasal air leakage and only autogenic fat tissue showed significant histologic differences in dogs at 6 months. This technique may also be useful for the treatment of patients with VPI.

Comparisons between fresh and cryopreserved fat injections in facial lipofilling

Background

Autologous fat is considered an ideal filler material, and the use of cryopreserved fat grafts is promising in terms of flexibility and efficiency. Therefore, cryopreserved fat grafts have become more common in recent years; however, their complications require further consideration.

Methods

We evaluated 53 patients who underwent facial lipofilling at our institution to confirm the clinical usefulness and safety of cryopreserved fat. Fresh fat injections with or without cryopreserved fat were administered. At one or more sites, 22 patients had a single fresh fat injection, four patients had two or more fresh fat injections, 16 patients had one fresh fat injection followed by one cryopreserved fat injection, six patients had one fresh fat injection followed by two cryopreserved fat injections, and five patients had two fresh fat injections and one or more cryopreserved fat injections.

Results

In total, 281 sets of injection procedures were performed at various sites, of which 170 involved one fresh fat injection, 89 involved one fresh fat injection and one cryopreserved fat injection, and 11 involved one fresh fat injection and two cryopreserved fat injections. One patient experienced self-resolving inflammation as a complication after the second injection in the right cheek. No statistically significant differences were found between the fresh and cryopreserved fat injections.

Conclusion

We suggest that cryopreserved fat is a useful and safe resource for multiple fat injections, with advantages including aseptic fat handling and the delicacy of the technique.

The Role of Fat Grafting in Buttock Augmentation

Autologous fat grafting is now considered the gold standard for buttock augmentation. Although a variety of techniques are currently being used by surgeons around the world, methods of fat grafting to the buttocks remain unsystematized, poorly understood, and controversial in terms of their safety and efficacy. Nonetheless, buttock augmentation by fat grafting has a satisfaction rate of 97.1%, and its mean complication rate has been estimated to be around 7 to 10%, with serious complications occurring in less than 1% of cases. Fat emboli are one such serious complication, with several reports in the literature discussing morbidity and mortality, specifically with intramuscular injection. With the increasing popularity of fat grafting for buttock augmentation, it is more important than ever to continue researching and learning to safeguard the satisfaction and safety of our patients.

Identification of the Optimal Recipient Layer for Transplanted Fat: A Prospective Study on Breast Lipoaugmentation

BACKGROUND

Fat grafting has become a popular procedure in aesthetic and reconstructive surgeries due to its safety, minimal invasiveness, and favorable visual outcomes, although the volume retention rate is unpredictable.

OBJECTIVES

A prospective clinical study on lipoaugmentation of the breast was conducted to compare fat retention rates in the pectoralis muscle and the periglandular area.

METHODS

This prospective study included 20 breasts from 11 patients who underwent primary lipoaugmentation. Volume retention rate and percentage augmentation among different recipient layers, as well as complications and patient satisfaction, were evaluated. Magnetic resonance imaging was performed preoperatively and at 1 day and 3 months postoperatively. Complications were recorded, and patient satisfaction was appraised through the use of the Breast-Q questionnaire.

RESULTS

Breasts were injected with 207 ± 29 mL of fat, achieving overall volume retention rates of 56.63% ± 16.40%. The overall augmentation was 21.53% ± 10.27%. Volume retention rate was significantly higher (59.00% ± 13.84%) in the periglandular area than in the pectoralis muscle (47.21% ± 22.41%) (P = 0.04). Augmentation was significantly higher (32.13% ± 12.96%) in the periglandular area than in the pectoralis muscle (4.95% ± 4.23%) (P = 0.00). Pain and numbness were the only reported complications. The Breast-Q score increased significantly for the measures "satisfaction with breasts," "psychosocial well-being," and "sexual well-being."

CONCLUSIONS

Fat transfer is a safe and acceptable method for aesthetic and reconstructive breast surgery. The periglandular area was a better recipient site than muscle for transferred fat.

LEVEL OF EVIDENCE: 4

Effects of Frozen Stromal Vascular Fraction on the Survival of Cryopreserved Fat Tissue

BACKGROUND

Nowadays, the use of cryopreserved fat tissue for soft tissue augmentation is common, except for its unpredictable fat graft absorption, and the toxicity of the cryoprotective agent remains a limitation. In this study, the effects of freezing stored fat tissue without a cryoprotector, and the addition of the stromal vascular fraction (SVF) on the survival of cryopreserved transplants was studied.

METHODS

Lipoaspirates from six donors were processed and cryopreserved at - 20 °C, - 80 °C and - 196 °C, respectively. The authors evaluated the lipoaspirates in vitro, on the basis of fat tissue and SVF viability after cryopreservation. In vivo fat grafting was performed in nude mice. Six trenches were injected on the backs of mice. Cryopreserved tissues (- 20 °C, - 80 °C and - 196 °C) were injected on the right side, and the other side received the SVF combination. At 4 and 8 weeks after transplantation, the authors examined the weight, volume and morphology of the tissue and analyzed histochemical staining and immunohistochemistry (i.e., DIL, CD31 and VWF) to evaluate the survival of the fat grafts.

RESULTS

After cryopreservation without the cryoprotective agent, adipose tissue maintained its morphology better in - 80 °C than - 20 °C and - 196 °C. SVF cells can retain their adhesive and proliferative properties after cryopreservation. Although cryopreservation caused damage to fat tissue, all explants showed intact adipocytes and vascular ingrowth. Most of all, the - 80 °C group had less graft resorption and fibrosis than the other temperature groups. There was increased survival of fat grafts in the SVF group compared with the control group.

CONCLUSION

In this study, the authors demonstrated that the storage temperature of - 80 °C was promising for 3 months of adipose tissue cryopreservation without a cryoprotective agent, and SVF could increase the survival rate of cryopreserved fat tissue.

NO LEVEL ASSIGNED

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 .

Safe Gluteal Fat Graft Avoiding a Vascular or Nervous Injury: An Anatomical Study in Cadavers

Background

Fat grafting for gluteal augmentation is one of the most popular aesthetic surgery procedures. It has an associated mortality to fat embolism of 0.2%.

Objectives

The authors of this study sought to describe which technique for synthetic graft application was least likely to cause a fat embolism.

Methods

Ten fresh bodies were obtained and 4 groups arranged with 5 buttocks each randomly assigned. Group 1 was infiltrated through the upper medial intergluteal sulcus (upper medial intergluteal sulcus) with an angulation of -30°, -10°, and 0°. Group 2 was infiltrated through the middle lower gluteal sulcus with an angulation of -30°, 0°, and +15°. Group 3 was infiltrated through a peritrochanteric (PT) access at the level of the femur head at 0° and +10° and in the middle of the buttock at the level of the posterior superior iliac crest at -30° toward the trochanter (lateral direction). Group 4 was infiltrated in the same manner as group 1 without -30°. A complication occurred when the graft was in contact with the vascular or nervous bundle, within the gluteus medius muscle, or both.

Results

Group 1 had 3 buttocks with a complication (UMIGS -30°). Group 2 had complications in all the injection techniques. Group 3 had 5 buttocks with a complication (PT at 0°). Group 4 had no complications.

Conclusions

The injection of the fat graft through the UMIGS at 0° and 10° angles, and through the middle of the buttock at the level of posterior superior iliac crest a -30° angle, reaches the surface needed for gluteal augmentation. The group 2 techniques should be avoided because they have a high risk of complication.

From Bedside to Bench: The Effect of Muscular Denervation on Fat Grafting to the Breast by Comparing Take Rate, Quality, and Longevity

BACKGROUND

Autologous fat grafting (AFG) to the breast is a frequent procedure in aesthetic and reconstructive surgery. Despite pure volume gain, questions remain regarding the engraftment rate, quality, and longevity. Little is known about the role of recipient tissue or innervation of the grafted area.

OBJECTIVES

The goal of this study was to determine the optimal recipient layer and muscular pretreatment of AFG.

METHODS

Fat was grafted to the breast, pectoralis muscle, or adjacent subcutaneous tissue of 42 rats. Nerve treatment included excision of a nerve segment, botulinum toxin (BTX) injection, or no treatment. Magnetic resonance imaging (MRI) and histological workup were carried out after 2 and 6 weeks.

RESULTS

Six weeks after AFG, the proportion of viable fat cells within the grafted fat stayed high (median, [IQR]: 81% [72% to 85%]). The signs of inflammation decreased over time. Intramuscular grafting with intact nerves had a decreasing effect on the viability of the grafted cells compared with subcutaneous treatment (-10.21%; 95% confidence interval [-21.1 to 0.68]).

CONCLUSIONS

If utilized on an intact nerve, intramuscular injection may lead to inferior results. If the nerve was cut or treated with BTX; however, intramuscular injection tends to be superior. These findings may prove interesting for future studies and eventual clinical application.

Safest Practices for Autologous Buttock Augmentation With Fat Grafting Using a Roller Pump Injection Technique

BACKGROUND

Autologous buttock augmentation with fat grafting has emerged as one of the preeminent modalities for body contouring employed by plastic surgeons today. Since 2009, we have used the roller pump injection technique.

OBJECTIVES

This procedure can be performed safely without specialized equipment and eliminates the tasks of manual graft preparation and injection. We describe our technique and standard safety measures. The anatomy of and complications associated with liposuction and fat grafting were recorded and reviewed.

METHODS

Retrospective chart review of 916 patients who underwent autologous buttock augmentation by this method from February 2009 to November 2016 was performed. All procedures were performed under general anesthesia at the same surgical center. Liposuction was performed and using a roller pump, the fat layer was propelled through an open-ended cannula into the recipient site.

RESULTS

Mean volume of fat removed and fat grafted in each patient was 3156 mL and 1807 mL per patient, respectively. There were complications in 13 patients for a rate of 1.4% with 10 (1.1%) related to fat grafting. Fourteen patients (1.5%) had subsequent procedures for volume and four patients (0.44%) for asymmetry. There were no venous thrombolic events, fat embolic events, or deaths.

CONCLUSIONS

The roller pump injection technique for buttock augmentation with fat grafting is safe and efficient. This technique minimizes preparatory effort and does not require additional equipment. We were unable to identify variables associated with complication risk due to the power of this study and the low percentage of complications.

LEVEL OF EVIDENCE 4

Latissimus Dorsi and Immediate Fat Transfer (LIFT) for Complete Autologous Breast Reconstruction

Supplemental Digital Content is available in the text.

Background:

Despite the popularity of latissimus dorsi (LD) flap in breast reconstruction, a breast implant is often necessary to achieve sufficient volume. Prior reports describe fat grafting to the LD flap as a secondary procedure to correct contour deformities and improve volume. Our institution has instituted autologous breast reconstruction with an LD flap and immediate fat transfer (LIFT).

Methods:

A retrospective review of all patients undergoing the LIFT procedure was undertaken. Patient age, total volume of fat transfer, length of follow-up, need for adjuvant therapy, and complications were recorded. The procedure begins with harvest of the LD flap and fat. Prior to disorigination of the latissimus muscle, fat is injected into the flap. Flap harvest is then completed and inset to create a breast mound.

Results:

Eighteen patients underwent LIFT procedures over 3 years with an average follow-up of 8.7 months (range, 2–24). Four breasts (22.2%) had previously received adjuvant radiation therapy. The mean total fat grafting volume was 515.5 mL (range, 325–730) per breast. The average estimated fat graft take was 66.8% (range, 50–80%). Four patients (22.2%) experienced complications.

Conclusion:

Autologous augmentation of the LD flap with lipotransfer has been used to avoid placement of an implant. We improve the technique by performing lipotransfer during index reconstruction. Furthermore, we perform lipotransfer prior to disorigination of the LD muscle to minimize trauma to the flap and increase the efficiency of fat grafting. Our experience demonstrates that this technique is a viable autologous alternative to microsurgical breast reconstruction.

Autologous breast reconstruction using the immediately lipofilled extended latissimus dorsi flap

BACKGROUND

The latissimus dorsi flap is a popular choice for autologous breast reconstruction. To dramatically improve volume, we report our experience of using the immediately lipofilled extended latissimus dorsi (ELD) flap and show it as a valid option for autologous breast reconstruction.

METHODS

Patients undergoing the procedure between December 2013 and June 2016 were included. Demographic, clinical and operative factors were analysed, together with in-hospital morbidity and duration of postoperative hospital stay.

RESULTS

A total of 71 ELD flaps with immediate lipofilling were performed. Forty-five reconstructions were immediate and the remaining 26 delayed. Median (range) volume of autologous fat injected immediately was 171 ml (40-630 ml). Contralateral reductions were performed in 25 patients with the median reduction volume 185 g (89-683 g). Median duration of admission was 6.5 (3-18) days and patients were followed up for 12 months (1-37). Three total flap failures occurred and had to be excised (4%). One haematoma occurred requiring drainage (1%). Signs of infection requiring intravenous antibiotics occurred in five patients (7%). In 5 patients wound dehiscence occurred, and only two of these required resuturing (3%). In total, 7 patients developed a seroma requiring repeated drainage (10%). Three reconstructions experienced mild mastectomy flap necrosis with no needing reoperation (4%).

CONCLUSIONS

Our experience represents the largest series to date and shows that in carefully selected patients the technique is safe, can avoid the requirement for implants, and has the potential to streamline the reconstructive journey.

Prevention of Fat Embolism in Fat Injection for Gluteal Augmentation, Anatomic Study in Fresh Cadavers

INTRODUCTION

Liposuction is a popular surgical procedure. As in any surgery, there are risks and complications, especially when combined with fat injection. Case reports of fat embolism have described a possible explanation as the puncture and tear of gluteal vessels during the procedure, especially when a deep injection is planned.

METHODS

A total of 10 dissections were performed in five fresh cadavers. Each buttocks was divided into four quadrants. We focused on the location where the gluteal vessels enter the muscle and the diameter of the vessels. Colorant at two different angles was injected (30° and 45°). We evaluated the relation of the colorant with the main vessels.

RESULTS

We found two perforators per quadrant. The thickness of the gluteal muscle was 2.84 ± 1.54 cm. The area under the muscle where the superior gluteal vessels traverse the muscle was located 6.4 ± 1.54 cm from the intergluteal crease and 5.8 ± 1.13 cm from the superior border of the muscle. The inferior gluteal vessels were located 8.3 ± 1.39 cm from the intergluteal crease and 10 ± 2.24 cm from the superior border of the muscle. When we compared the fat injected at a 30° angle, the colorant stayed in the muscle. Using a 45° angle, the colorant was in contact with the superior gluteal artery and the sciatic nerve. No puncture or tear was observed in the vessels or the nerve.

CONCLUSIONS

The location where the vessels come in contact with the muscle, which can be considered for fat injection, were located in quadrants 1 and 3. A 30° angle allows for an injection into the muscle without passing into deeper structures, unlike a 45° injection angle.

Lower Leg Augmentation with Fat Grafting, MRI and Histological Examination

INTRODUCTION

Nowadays, there is an increasing demand for contouring of the entire lower leg, in addition to corrections at the level of the muscle only. Accordingly, it becomes advantageous to use fat tissue for this purpose, for its availability in high quantities, potential for its easy implantation in all leg parts, biological compatibility, low antigen potential, and minimal donor morbidity.

METHODS

Forty-eight female patients, aged 20-54 (47.1 % younger than 35 and 52.9 % older than 35), underwent lower leg augmentation with autologous fat. We compared pre- and 1, 3, and 6 months postoperative morphological and volumetric characteristics of the recipient region by circumferential measuring of particular parts of the lower legs and evaluating the presence of live transplanted fat by MRI and histological examination.

RESULTS

The augmentation of certain circumferences of the lower leg at the 6-month follow-up examination is significantly related to preoperative circumference as well as to the quantity of infiltrated fat. Therefore, lower the baseline circumference, the greater the augmentation, and the greater the quantity of infiltrated fat, the greater the augmentation.

CONCLUSION

Ensuring adequate technique in the transfer of fat tissue from the donor region to the recipient region of the lower leg is definitely the least invasive method of lower leg contouring. For patients with muscle dystrophies or those with injuries, this technique could become the first choice for its minimal complications. The simplicity of the procedure invites its wide application in plastic surgery.

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 A3 online Instructions to Authors. www.springer.com/00266 .

Reconstruction of gluteal deformities: a systematic review and experience of four cases

BACKGROUND

The reconstruction of gluteal deformities remains a major challenge. The aim of this article is to provide a systematic review of the literature concerned, and to present a case series with representative defects from various zones.

METHODS

A review of the literature was performed using PubMed, EMBASE, and The Cochrane Library, in accordance with the PRISMA statement. Quality of evidence was rated according to GRADE. Patients with various buttock deformities were included and, depending on the defect, the reconstructive techniques applied consisted of lipoinjection, local fasciocutaneous flap, or pedicled gracilis muscle flap. Complications, patient's pain assessment, impairment in everyday-life activities, aesthetic outcome, objective assessment of sensitivity, and recurrence were considered.

RESULTS

A total of 498 records were identified in the literature search. Of those, 12 studies met the PICOS (participants, interventions, comparators, outcomes, and study design) criteria. Overall, 41 patients were analysed, the evidence of which was of low quality. In this study, four patients (three female and one male) with a mean age of 44 ± 15 years were operated on between 2010-2014. The mean operation time was 83 ± 30 minutes. One patient required revision due to persistent seroma and recurrence, and one patient required neurolysis and gracilis denervation due to neuroma and scarring. After a mean follow-up of 40 ± 21 months, the results were functionally and cosmetically satisfactory.

CONCLUSIONS

Reconstruction of buttock deformities using an integrated approach can lead to a long-lasting, functionally and aesthetically satisfactory result. However, evidence is limited due to the lack of good-quality studies.

Anatomy of Facial Recipient Sites for Autologous Fat Transfer

Introduction:

Autologous fat transfer is an increasingly popular treatment for the aging face. Recently, studies have suggested increased duration of effect with the injection of fat into or adjacent to muscles. Subcutaneous depths of facial muscles have been demonstrated using cadaver dissections, but to our knowledge this is the first study to use radiologic measurements in living subjects in order to quantify muscle depths in the face.

Materials and Methods:

Forty computed tomography (CT) scans were reviewed retrospectively using digital radio imaging software with a calibrated digital measurement tool that was used to measure the depths of the muscles of facial expression corresponding to fat-grafting sites. Correlation was made to formalin-preserved cadaver dissections.

Results:

Subcutaneous depths of facial muscles are listed as measured radio graphically and on cadaver sections.

Discussion:

The depths of the muscles of facial expression are more accurately measured using digital radiographs; these depths are important landmarks for facial cosmetic surgeons performing an autologous fat transfer. To our knowledge, this is the first study to characterize the anatomic depth of the facial muscles in the living human.

Application of Hydrogel in Reconstruction Surgery: Hydrogel/Fat Graft Complex Filler for Volume Reconstruction in Critical Sized Muscle Defects

Autogenic fat graft usually suffers from degeneration and volume shrinkage in volume reconstruction applications. How to maintain graft viability and graft volume is an essential consideration in reconstruction therapies. In this presented investigation, a new fat graft transplantation method was developed aiming to improve long term graft viability and volume reconstruction effect by incorporation of hydrogel. The harvested fat graft is dissociated into small fragments and incorporated into a collagen based hydrogel to form a hydrogel/fat graft complex for volume reconstruction purpose. In vitro results indicate that the collagen based hydrogel can significantly improve the survivability of cells inside isolated graft. In a 6-month investigation on artificial created defect model, this hydrogel/fat graft complex filler has demonstrated the ability of promoting fat pad formation inside the targeted defect area. The newly generated fat pad can cover the whole defect and restore its original dimension in 6-month time point. Compared to simple fat transplantation, this hydrogel/fat graft complex system provides much improvement on long term volume restoration effect against degeneration and volume shrinkage. One notable effect is that there is continuous proliferation of adipose tissue throughout the 6-month period. In summary, the hydrogel/fat graft system presented in this investigation demonstrated a better and more significant effect on volume reconstruction in large sized volume defect than simple fat transplantation.

Morphological features of cell death and tissue remolding of fat grafts

BACKGROUND

Fat tissue graft has been commonly used for soft tissue augmentation. However, the mechanisms underlying the maintenance of graft volume and weight are still unclear. As morphological features provide direct evidences for cell death and survival, we aimed to investigate the fate of grafted adipocytes and the dynamic changes in the remodeling of adipose tissues by transmission electron microscopy technique.

METHODS

The unilateral inguinal fat pad of C57BL/6J mice was autografted to the dorsa of the mice. Perilipin expression and morphological changes were investigated by immunohistochemistry staining and transmission electron microscopy, respectively, in grafted tissues collected at posttransplantation days 0, 1, 3, 5, 7, 14, and 30.

RESULTS

Transmission electron microscopy analysis revealed that most adipocytes in grafts showed traits of cell death on postgrafting day 3. Multilocular adipocytes with naive nuclei were observed as early as day 5 and a larger number of multilocular adipocytes were found on day 14. Perilipin immunostaining revealed that only some adipocytes located in the margin of grafts survived through the ischemic injury. New adipocytes were visualized at the periphery of the grafts, although the scope of viable adipocyte zonal areas increased from day 5 to day 30.

CONCLUSIONS

The results provide ultrastructural evidences associated with the remodeling dynamics of adipose tissue grafts. It is suggested that maximized volume of graft should be obtained through promoting regeneration other than improving survival of grafted adipose tissues.

Maximizing the Volume of Latissimus Dorsi Flap in Autologous Breast Reconstruction with Simultaneous Multisite Fat Grafting

BACKGROUND

The pedicled latissimus dorsi (LD) flap serves an important function in breast reconstruction, but its utility is limited by its inability to provide sufficient breast volume.

OBJECTIVES

The purpose of this preliminary report was to review the techniques and outcomes of utilizing fat-grafted, volume-enhanced LD flap transfer with fat grafting recipient sites in autologous breast reconstruction.

METHODS

A retrospective study was performed of 10 patients (14 breasts) who underwent autologous breast reconstruction utilizing the LD flap transfer technique and simultaneous fat grafting between August 2012 and September 2014. Multilayer, multisite fat grafting was performed to the LD muscle, LD skin paddle, mastectomy skin flaps, and the pectoralis major and serratus muscles simultaneously with the LD flap transfer.

RESULTS

Three patients underwent an immediate breast reconstruction, four underwent a delayed breast reconstruction, and four underwent a tertiary breast reconstruction following previously failed breast reconstructions (one patient underwent each of the first two procedures, one on each breast). The average age of the patients was 55 years (range, 39-76 years), the average body mass index of the patients was 29.3 (range, 19.6-39.9), and the average fat grafting volume for the patients was 176 mL (range, 50-300 mL). There was 100% flap survival and complete wound healing. No seroma or fat grafting-related complications were clinically detected. Three patients required additional fat grafting.

CONCLUSIONS

The fat-grafted, volume-enhanced LD flap procedure with fat grafting recipient sites offers a simple and safe technique for autologous breast reconstruction, with low morbidity and fast recovery. It can be a useful alternative to utilizing abdomen-based flaps in autologous breast reconstruction or could be performed to salvage both implant-based and free-flap breast reconstructions. LEVEL OF EVIDENCE 4: Therapeutic.

Deaths Caused by Gluteal Lipoinjection: What Are We Doing Wrong?

BACKGROUND

Intramuscular gluteal lipoinjection has become one of the most commonly used surgical procedures for achieving improvement in the gluteal contour; however, there are few studies that report and analyze the causes of secondary death from this surgical procedure.

METHODS

An analysis of secondary deaths from gluteal lipoinjection procedures was performed in Mexico and Colombia over periods of 10 and 15 years, respectively. In Mexico, the study was performed through a survey of all members of the Mexican Association of Reconstructive, Plastic and Aesthetic Surgery. In Colombia, the study was performed through an analysis of deaths and autopsies documented by the National Institute of Legal Medicine and Forensic Sciences Regional Bogotá.

RESULTS

A total of 413 Mexican plastic surgeons reported 64 deaths related to liposuction, with 13 deaths caused by gluteal lipoinjection. In Colombia, nine deaths were documented. Of the 13 deaths in Mexico, eight (61.6 percent) occurred during lipoinjection, whereas the remaining five (38.4 percent) occurred within the first 24 hours. In Colombia, six deaths (77.7 percent) occurred during surgery and three occurred (22.2 percent) immediately after surgery. In the Colombian autopsy results, seven cases of macroscopic fat embolism and two cases with a microscopic embolism were reported, with abundant fatty tissue in the infiltrated gluteal muscles.

CONCLUSIONS

In this study, the authors found that intramuscular gluteal lipoinjection is associated with mortality caused by gluteal blood vessel damage allowing macroscopic and microscopic fat embolism; therefore, buttocks lipoinjection should be performed very carefully, avoiding injections into deep muscle planes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Volumetric evaluation of fat resorption after breast lipofilling

INTRODUCTION

The fat transfer or the lipofilling is a technique that had a major impact on the breast surgery results. We have been using this technique since 1998 as an adjuvant in breast reconstruction. The transferred fat is partially resorbed in the first three months after fat grafting. Literature shows that fat resorption varies from 30 to 80% and the experimental studies register a variation between 50 and 90%. The difficulty of the lipomodeling consists in anticipating the fat resorption rate in order to obtain breast symmetry. The purpose of this article is to evaluate the resorption rate of the transferred fat in the reconstructed breast by means of volumetric imaging 3 months after fat grafting.

MATERIAL AND METHODS

A prospective study was undertaken including breast reconstructions with total autologous latissimus dorsi. All the surgical procedures have been done by the same surgeon (1st author). It focused on the second stage of breast reconstruction: the lipofilling. We registered the average harvested volumes, the volumes obtained after centrifugation and the transferred volumes for every reconstructed breast. The intramuscular volume in the reconstructed breast was measured by volumetric imaging on the third day after lipofilling (D3) and three months after lipofilling (M3). The volumetry was performed by using an after treatment console SIEMENS (SOMATOM definition AS 2*64 barettes). The average intramuscular volume was registered at D3 and M3. The average volume difference was calculated in order to obtain the exact resorption rate.

RESULTS

This prospective study was undertaken on 32 reconstructed breasts by total autologous latissimus dorsi flap. The average age was 52 years, the average BMI was 24.7 kg/m(2). The average harvested fat volume for the breast lipofilling was 560 cc and the volume obtained after centrifugation was evaluated at about 371 cc, the average fat volume transferred being 291 cc. The volumetric study showed that intramuscular volume at D3 was measured at 284 cc and at M3 about 223 cc, of a resorption intramuscular rate of 21.5%.

CONCLUSION

In our study, the rate of resorption of the fat transferred to the muscle in the reconstructed breast was measured at 21.5%. The low resorption rate found in our study, lower than those in the literature, sustains the supposition that the muscle is an excellent receiving matrix for the fat tissue. In order to obtain this percentage, a learning curve is necessary. Once acquired, this technique produces a major improvement of the breast surgery results.

The discordant histology of grafted fat: a systematic review of the literature

BACKGROUND

All combinations of harvesting, processing, and injection have been attempted to maximize fat graft take following transplantation. Two theories behind fat transplantation have been proposed: cell survival and host replacement. Although the cell survival theory states that fat cells survive and undergo neovascularization following transfer, host replacement theory predicts adipocyte necrosis and replacement of cells by host tissues. Whether or not transferred fat survives, proliferates, or is replaced by fibrous tissue is relevant for the investment of future resources into this thriving field of research.

METHODS

A literature search of the MEDLINE and Cochrane databases was performed for studies focusing on the histology of grafted fat after transplantation up to December of 2013. Histologic examinations of grafted fat were reviewed and compared in humans and animals.

RESULTS

Sixty-six articles met inclusion criteria, and eight of them were human studies. There was widespread diversity in the method of fat harvest and transfer among the studies, and the date of examination after transfer. Many studies reported the presence of viable adipocytes, although an extensive amount of fibrosis and inflammatory infiltration was also seen, depending on the period of examination.

CONCLUSIONS

Free fat grafts show a variable response following transplantation, with significant disagreement in the reported evidence. Although neovascularization and preservation of adipocyte architecture appear possible, other fat grafts are completely replaced by necrotic ghost cells and fibrotic ingrowth. Adipocyte survival likely contributes to volume maintenance, but fibrosis may also play a role.

Comparison of the viability of cryopreserved fat tissue in accordance with the thawing temperature

Background

Adipose tissue damage of cryopreserved fat after autologous fat transfer is inevitable in several processes of re-transplantation. This study aims to compare and analyze the survivability of adipocytes after thawing fat cryopreserved at -20℃ by using thawing methods used in clinics.

Methods

The survival rates of adipocytes in the following thawing groups were measured: natural thawing at 25℃ for 15 minutes; natural thawing at 25℃ for 5 minutes, followed by rapid thawing at 37℃ in a water bath for 5 minutes; and rapid thawing at 37℃ for 10 minutes in a water bath. The survival rates of adipocytes were assessed by measuring the volume of the fat layer in the top layers separated after centrifugation, counting the number of live adipocytes after staining with trypan blue, and measuring the activity of mitochondria in the adipocytes.

Results

In the group with rapid thawing for 10 minutes in a water bath, it was observed that the cell count of live adipocytes and the activity of the adipocyte mitochondria were significantly higher than in the other two groups (P<0.05). The volume of the fat layer separated by centrifugation was also measured to be higher, which was, however, not statistically significant.

Conclusions

It was shown that the survival rate of adipocytes was higher when the frozen fat tissue was thawed rapidly at 37℃. It can thus be concluded that if fats thawed with this method are re-transplanted, the survival rate of cryopreserved fats in transplantation will be improved, and thus, the effect of autologous fat transfer will increase.