Coleman Technique Research Articles

Structural and microwave characterization of Ni0.2CoxZn0.8−xFe2O4 for antenna applications

Abstract Nickel–cobalt–zinc ferrites, Ni 0.2 Co x Zn 0.8− x Fe 2 O 4 (with x =0, 0.2, 0.4, 0.6, 0.8,) have been prepared using the auto-combustion method. X-ray diffraction, Fourier transform infrared (FT-IR) and Raman spectroscopy confirmed the cubic spinel structure of the ferrites. Microwave dielectric constant ( e r ) and quality factor ( Q × f ) were measured by using the Hakki–Coleman technique. Dielectric constant calculated using the Clausius–Mossoitti relation showed good agreement with the experimental value. Relative permeability of the ferrites was calculated by using the Nicholson–Ross–Weir conversion technique. Dielectric constant ( e r ) decreased from 7.474 to 5.548 and temperature coefficient of resonant frequency ( τ f ) increased from −75.85 ppm/°C to −19.32 ppm/°C, respectively, and relative permeability increased from 2.1085 to 3.2179 with increase in Cobalt content. The composition Ni 0.2 Co 0.2 Zn 0.6 Fe 2 O 4 was used to develop ferrite resonator antennas (FRA) and was studied in cylindrical, triangular and cuboid shapes with co-axial probe feeding mechanisms. The antenna characteristics were simulated using high frequency structure simulation (HFSS) software and a good agreement has been achieved between the measured and simulated results. The cuboid shaped FRA show maximum bandwidth of 990 MHz, while the cylindrical shaped FRA show a maximum gain of 3.48 dB, respectively.

Combining decellularized human adipose tissue extracellular matrix and adipose-derived stem cells for adipose tissue engineering

Repair of soft tissue defects resulting from lumpectomy or mastectomy has become an important rehabilitation process for breast cancer patients. This study aimed to provide an adipose tissue engineering platform for soft tissue defect repair by combining decellularized human adipose tissue extracellular matrix (hDAM) and human adipose-derived stem cells (hASCs). To derive hDAM incised human adipose tissues underwent a decellularization process. Effective cell removal and lipid removal were proved by immunohistochemical analysis and DNA quantification. Scanning electron microscopic examination showed a three-dimensional nanofibrous architecture in hDAM. The hDAM included collagen, sulfated glycosaminoglycan, and vascular endothelial growth factor, but lacked major histocompatibility complex antigen I. hASC viability and proliferation on hDAM were proven in vitro. hDAM implanted subcutaneously in Fischer rats did not cause an immunogenic response, and it underwent remodeling, as indicated by host cell infiltration, neovascularization, and adipose tissue formation. Fresh fat grafts (Coleman technique) and engineered fat grafts (hDAM combined with hASCs) were implanted subcutaneously in nude rats. The implanted engineered fat grafts maintained their volume for 8weeks, and the hASCs contributed to adipose tissue formation. In summary, the combination of hDAM and hASCs provides not only a clinically translatable platform for adipose tissue engineering, but also a vehicle for elucidating fat grafting mechanisms.

SAT0203 Autologous Fat Transfer for Digital Ulcers Treatment in Systemic Sclerosis

BackgroundDigital ulcers (DUs) occur in up to 50% of patients with Systemic Sclerosis (SSc). DUs are painful and lead to disability. DUs are more or less extended, often multiple, with...

Structural, optical and microwave dielectric properties of Sr1−xCaxWO4 ceramics prepared by the solid state reaction route

Abstract Strontium calcium tungstates (Sr 1− x Ca x )WO 4 crystals (with x =0; 0.1, 0.2, 0.3, 0.4, 0.5, 0.6,0.7, 0.8, 0.9 and 1.0) were prepared by the standard wet milling ceramic preparation method. X-ray diffraction (XRD), Fourier transform Raman (FT-Raman) and Fourier transform infrared (FT-IR) spectroscopic techniques indicate that all the crystals present a scheelite-type tetragonal structure without deleterious phases. FT-Raman spectra exhibited six Raman active modes in the range from 100 to 1000 cm −1 , while the FT-IR spectra present different infrared active modes for W–O within the wave number range from 500 to 1000 cm −1 . Optical properties were investigated by ultraviolet visible (UV–vis) absorption and photoluminescence (PL) measurements. UV–vis absorption measurements evidenced an increase in the values of the optical band gap (from 5.80 to 5.92 eV) with the increase of Ca into the SrWO 4 lattice. All compositions show broad blue PL emission at room temperature when excited with 250 nm wavelength. Dielectric constant, temperature coefficient of resonant frequency ( τ f ) and quality factors were measured with the Hakkie–Coleman technique. The permittivity was found to increase with the increase in Ca content, in agreement with the Clausius–Mosotti relation. The value of τ f was found to be −44.61 ppm/°C for SrWO 4 which increased to −19.69 ppm/°C for CaWO 4 .

Correction of sequelae of rhinoplasty by lipofilling

Rhinoplasty sequelae can be difficult to treat, especially in patients with thin skin. Autologous fat grafting is already used in numerous applications in plastic surgery. However, its use in the nasal region remains relatively uncommon. Given its volumetric qualities and its action on cutaneous trophicity, adipose tissue can be considered the reference product for filling. From 2006 to 2012, 20 patients were treated by autologous fat injections according to the Coleman technique in order to correct rhinoplasty sequelae. The procedures were performed under local or general anaesthesia. The quantity of adipose tissue injected ranged from 1 to 6cc depending on the size of the deformation and the zone being injected: dorsum irregularities, inverted V deformations, visible lateral osteotomies and saddle nose deformity. Of the 20 patients followed up for 18-24 months, 18 had satisfactory aesthetic results after one procedure and two required a second session. Our experience gradually led us to design micro-cannulae for greater injection precision and enabled us to perform these procedures under local anaesthesia. The reduction in ecchymoses and postoperative oedema through the use of these cannulae has significantly reduced convalescence time. In patients who undergo multiple procedures, lipofilling can be a simple and reliable alternative to correct imperfections following rhinoplasty.

Structural, optical and microwave dielectric properties of Ba1−xSrxWO4 ceramics prepared by solid state reaction route

In this paper, Barium Strontium Tungstate (Ba1−xSrx)WO4 crystals with (x = 0; 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0) were prepared by standard wet milling ceramic preparation method. These crystals were structurally characterized by X-ray diffraction (XRD), Fourier transform Raman (FT-Raman) and Fourier transform infrared (FT-IR) spectroscopic techniques. The shape, growth and average crystal size distribution of these crystals were investigated by a scanning electron microscope (SEM). Their optical properties were investigated by ultraviolet visible (UV–vis) absorption and photoluminescence (PL) measurements. XRD patterns, Rietveld refinements data, FT-Raman and FT-IR spectroscopies indicate that all the crystals present a scheelite-type tetragonal structure without deleterious phases. FT-Raman spectra exhibited 6 Raman active modes in range from 100 to 1000 cm−1, while the FT-IR spectra presented 2 infrared active modes in range from 500 to 1000 cm−1. SEM micrographs showed well sintered BaWO4 grains, while the substitution of Sr induced modifications in the shape and reduction in the grain size. UV–vis absorption measurements evidenced an increase in the values of the optical band gap (from 4.36 to 4.53 eV) with the increase of Sr into BaWO4 lattice. Dielectric constant, temperature coefficient of resonant frequency (τf), quality factors were measured with Hakki–Coleman technique. The value of τf found −43.68 ppm/°C for BaWO4 which increased to −21.40 ppm/°C for the SrWO4.

Micro-Computed Tomography Evaluation of Human Fat Grafts in Nude Mice

Although autologous fat grafting has revolutionized the field of soft tissue reconstruction and augmentation, long-term maintenance of fat grafts is unpredictable. Recent studies have reported survival rates of fat grafts to vary anywhere between 10% and 80% over time. The present study evaluated the long-term viability of human fat grafts in a murine model using a novel imaging technique allowing for in vivo volumetric analysis. Human fat grafts were prepared from lipoaspirate samples using the Coleman technique. Fat was injected subcutaneously into the scalp of 10 adult Crl:NU-Foxn1(nu) CD-1 male mice. Micro-computed tomography (CT) was performed immediately following injection and then weekly thereafter. Fat volume was rendered by reconstructing a three-dimensional (3D) surface through cubic-spline interpolation. Specimens were also harvested at various time points and sections were prepared and stained with hematoxylin and eosin (H&E), for macrophages using CD68 and for the cannabinoid receptor 1 (CB1). Finally, samples were explanted at 8- and 12-week time points to validate calculated micro-CT volumes. Weekly CT scanning demonstrated progressive volume loss over the time course. However, volumetric analysis at the 8- and 12-week time points stabilized, showing an average of 62.2% and 60.9% survival, respectively. Gross analysis showed the fat graft to be healthy and vascularized. H&E analysis and staining for CD68 showed minimal inflammatory reaction with viable adipocytes. Immunohistochemical staining with anti-human CB1 antibodies confirmed human origin of the adipocytes. Studies assessing the fate of autologous fat grafts in animals have focused on nonimaging modalities, including histological and biochemical analyses, which require euthanasia of the animals. In this study, we have demonstrated the ability to employ micro-CT for 3D reconstruction and volumetric analysis of human fat grafts in a mouse model. Importantly, this model provides a platform for subsequent study of fat manipulation and soft tissue engineering.

Autologous Fat Grafting for Correction of Unaesthetic Scars

Autologous fat grafting has many clinical applications, and its use in Plastic Surgery is increasing. Currently, autologous fat grafts are used in breast surgery, facial rejuvenation, and facial lipoatrophy secondary to antiretroviral therapy and as a treatment for liposuction sequelae, buttock augmentation, and congenital facial hemiatrophy. Their use is expanding rapidly, and their applications in other fields are an ever growing interest within the Plastic Surgery community. To introduce a new application of lipoinjection for the correction of unaesthetic, retracted, or sunken scars. The study consisted of a total of 8 patients (6 women and 2 men), with a mean age of 47 years old, all of whom presented retractile and dystrophic scars in the abdomen (n = 3), arm (n = 1), male breast (n = 1), and face (n = 3). They all received treatment with a fat injection using Coleman technique. General anesthesia was used in 3 patients; deep intravenous sedation plus local anesthesia was used in the remaining 5 patients. A COL-ASP15 cannula was used to harvest the fat and a blunt-tipped COL-19 cannula (Byron Medical) to release the fibrosis and retraction, and for the fat grafting injection. A 4-grade visual scale was use to evaluate the results. An improvement in the scar was achieved in all patients. One operation was required in 5 cases, and 2 operations in 3 cases. There were no complications in any patient and the results were lasting in all cases (the mean follow-up period was of 18 months). Autologous fat grafting is a good method for correction of retracted or sunken scars instead of the traditional scar surgical excision.

Development of micro-injection as an innovative autologous fat graft technique: The use of adipose tissue as dermal filler

Autologous fat graft, by virtue of its volumetric qualities and its action on skin trophicity, can be considered as a gold standard implant. Current techniques do not allow very superficial or subdermal injections of adipose tissue. The authors report technical modifications that enable fat transfer through a 25-gauge cannula. The viability of grafted fat was assessed after subcutaneous injection on a murine model. Micro-fat grafting consists of harvesting fat tissue using a multiperforated cannula with holes of 1mm. Fat tissue is refined as described by SR Coleman and transferred through a micro-cannula. Initially, human fat was first harvested using two different procedures: Coleman's technique and the modified harvesting technique. Preliminary comparative histologic analyses were performed. Sixteen nude mice received human fat tissue: one side was filled with 0.7cc through a 17-G cannula using Coleman's technique, and the opposite side was grafted using smaller cannulae (20G, 23G and 25G) following the modified harvesting technique. Mice were euthanised at 12 weeks and skin biopsies were performed. Experimental fat grafts on mice were observed and analysed: macroscopically, the fat tissue of each side showed the same healthy aspect. Haematoxylin-eosin-saffron staining revealed intact adipocytes and anti-CD31 antibody immunohistochemical staining highlighted an abundant neo-vessel network. Fat graft obtained by the modified technique maintains a normal histologic structure. Fat injection with micro-cannulae extends the application of lipostructure to the superficial layers of the skin.

Structural, microwave dielectric properties and dielectric resonator antenna studies of Sr(ZrxTi1−x)O3 ceramics

Compositionally induced phase transitions in the system Sr(ZrxTi1−x)O3 were analyzed using a combination of X-ray diffraction, FT-Raman and FTIR spectroscopy. Sr(ZrxTi1−x)O3 system showed at least two tilting of phase transitions, pm3m–I4mcm and I4/mcm–pnma. The structural transition occurred due to tilting of BO6 octahedra. Dielectric constant measured with Hakki–Coleman technique decreased from 253 to 25 with increase of Zr content. The value of τf found 1771ppm/°C for SrTiO3 which decreased to −82ppm/°C for the SrZrO3. The dielectric resonator antenna (DRA) was investigated experimentally and numerically using a monopole antenna through an infinite ground plane and Ansoft's high frequency structure simulator software, respectively. The required resonance frequency and bandwidth of DRA were investigated in the composition between 0≤x≤1.0.

Lipofilling of Perineal and Vaginal Scars

Sir:FigureChronic pain after episiotomy caused by scar contracture or neuroma formation remains a serious problem.1 The therapy of choice can be simple resection of the scar tissue with primary wound closure or local flaps. Recovery after these corrections may take time, with the risk of receiving no improvement, more pain, or poor cosmetic results. We have performed a prospective study with assessment of perineal/vaginal pain and sexual functioning before and after autologous free fat transplantation for correction of scars following childbirth in 20 patients (mean age, 34 ± 7.5 years; mean time after episiotomy, 10.3 ± 2.3 months). Mediolateral episiotomy had been performed in 18 patients. Two patients had pain after perineal laceration. Three patients have had correction of the scars with primary excision and no signs of improvement 6 months ago. All patients reported dyspareunia and other pain-related problems. Lipofilling was performed according to the Coleman technique,2 with scar release and implantation into parallel tunnels on multiple layers under the scars (Fig. 1). A special technique of infiltration with one finger in the vagina and another in the rectum was used to avoid injury of the rectum in case of lipofilling of scars of the posterior wall of the vagina. Perineal pain was assessed preoperatively and at different time points after lipofilling using the short-form McGill Pain Questionnaire, including the Present Pain Intensity index and a visual analogue scale.3 Sexual functioning was assessed with a revised Sabbatsberg Sexual Self-Rating Scale before and after intervention.4 Follow-up of the patients was scheduled after 1, 3, and 6 months. The distribution of variables within the patient group was compared by nonparametric analysis of variance (two-sample Wilcoxon test), and differences between dependent (paired) data were assessed by the nonparametric paired test (signed rank test). A value of p < 0.05 was considered to be statistically significant. An average volume of 12 ± 3 cc of autologous fat was injected (range, 7 to 15 cc). Four patients underwent two lipofilling sessions because of improvement with the first lipofilling but had remaining painful areas in one part of the scar. The average interval between these sessions was 4 ± 1.5 months. All patients made good postoperative recovery without major complications. Eighteen of 20 patients had an immediate subjective improvement of their pain obviously attributable to release of severe scar contractures. One month after lipofilling, the short-form McGill Pain Questionnaire score was significantly reduced in comparison with the score before treatment (p < 0.05) (Fig. 2). Three and 6 months after treatment, the score had decreased further (p < 0.05). The Present Pain Intensity index and visual analogue scale score were also significantly reduced after 1, 3, and 6 months (p < 0.05). The Sabbatsberg Sexual Self-Rating Scale score showed a significant increase after lipofilling (p < 0.05). Fifteen patients were very satisfied with the small operation and five were satisfied.Fig. 1: Release of scar tissue combined with fat injection 8 months after mediolateral episiotomy in a 28-year-old patient with dyspareunia.Fig. 2: Short-form McGill Pain Questionnaire scores before and 1, 3, and 6 months after lipofilling in patients with episiotomy and perineal laceration (*p < 0.05 versus before).A number of studies recently demonstrated the reliability, long-term stability, and safety of autologous free fat transplantation in reconstructive procedures.5 In our opinion, lipofilling also seems to be a promising treatment for correction of perineal/vaginal scars after episiotomy and perineal laceration. It is well tolerated and offers encouraging results, with improvement of pain and better sexual function. Dietmar Ulrich, M.D., Ph.D. Franziska Ulrich, M.D. Department of Plastic and Reconstructive Surgery Lena van Doorn, M.D., Ph.D. Department of Gynecology Steven Hovius, M.D., Ph.D. Department of Plastic and Reconstructive Surgery, Erasmus University Hospital, Rotterdam, The Netherlands DISCLOSURE The authors have no financial interest in this research project or in any of the techniques or equipment used in the study. The authors have no conflicts of interest to disclose.

The Effect of Botulinum Toxin A on Fat Graft Survival

Autologous fat grafting is a common procedure used in plastic surgery to correct soft tissue deficiency or depression deformity. However, absorption of grafted fat in the recipient area is unpredictable, and various methods for improving fat survival have been developed clinically. This study analyzed the changes and viability of injected fat in relation to the effects of botulinum neurotoxin type A (BoNTA). Fat tissue was harvested from the pre-urinary bladder cavity of four Sprague-Dawley rats and processed using the Coleman technique. The experiment was performed on the backs of eight BALB/c-nu mice. The injection of free fat grafts was performed on the bilateral side of the back of each mouse. The one side (experimental) was treated with 0.5 ml of a free fat injection combined with 0.5 IU of BoNTA in 0.1 ml of saline. The other side (control) was treated with 0.5 ml of free fat injection combined with 0.1 ml of saline. The mice were killed after 9 weeks, and the injected fat grafts were explanted, after which the weight and volume were measured. Histologic study was performed with hematoxylin and eosin staining. Statistical analysis of the weight and volume from both sides, the histologic parameters, and cellular integrity was performed. A difference in the weight, volume, and histologic parameters of the injected fat grafts was observed. The BoNTA-treated side exhibited a significantly higher survival rate than the control side. The histologic examination of the fat grafts also demonstrated that the grade scale of cellular integrity was higher for the BoNTA-treated sides. Botulinum toxin A significantly reduces the level of fat graft resorption. Therefore, an injected fat graft can be used in conjunction with botulinum toxin A and offers better volumetric improvement. 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 at www.springer.com/00266.

Vitalitätsvergleich von Fetttransplantaten welche mit der Coleman Technik und dem Tissu Trans System (Shippert Methode) gewonnen wurden

Various methods for harvesting and refining autologous fat grafts have been described. One of the standard procedures, the Coleman technique, is based on manual aspiration to reduce the negative presssure and the centrifugation of the grafts. The Shippert technique uses automatic liposuction with reduced negative pressure and abstains from centifugation in order not to reduce viability of the graft by exposing it to centrifugal forces. This study intends to compare the viability of fat grafts processed with the above-mentioned methods.Fat grafts were obtained in 9 patients by using both the Tissu Trans system (Shippert technique) and the Coleman technique. To evaluate the impact of centrifugation forces, the grafts harvested with the Coleman technique were treated with standard adjustment of the centrifuge and also with doubled g-force. Viability of fat grafts was analysed with the WST-8 test and with annexin V/PI assay FACS analysis.The viability of fat grafts processed by the Coleman technique was significantly higher compared to the Shippert technique on applying the WST-8 test. Applying the annexin V/PI analysis, the viability of fat grafts was almost equal with both techniques. Whereas the fat grafts processed with the Tissu Trans system are injected without condensation, the grafts refined with the Coleman technique were concentrated 3 times by centrifugation compared to the primary liposuctioned graft volumes.The Coleman technique allows the preparation of a fat graft containing more viable cells than the Shippert technique. This is in part due to the condensation of the graft by centrifugation using the Coleman technique. The factor of condensation of the grafts harvested and refined with the Coleman technique exceeds the factor of increased fat graft viability in comparison to the Shippert technique. The Tissu Trans system is more than twice as fast and easier to use with a preferential use for large volume grafts like in breast augmentation, whereas the Coleman technique produces a more condensed graft, favouring it for fat grafting to the face where less volume is needed.

Lipoescultura facial: técnica quirúrgica y revisión bibliográfica

This review shows that autologous fat grafting is useful for filling the soft tissues of the face for cosmetic and reconstructive purposes. The literature on liposculpture techniques published on PubMed was reviewed. The Coleman technique, subdermal technique, and intramuscular infiltration are described, in addition to their primary modifications, and the agents used to improve fat graft maintenance were studied.

La lipostructure dans les séquelles de brûlures faciales

Fat graft is now part of the armamentarium in face plastic surgery. It is successfully used in burn scars. The aim of our study is the discussion of the value of this technique in optimizing cosmetic result of burns face sequelae. Fifteen adult patients (10 females and five males) with scars resulting from severe burns 2 to 9 years previously were selected. The patients were treated by injection of adipose tissue harvested from abdominal subcutaneous fat and processed according to Coleman's technique. Two to three injections were administered at the dermohypodermal junction. Ages, sexes, aetiology of burn, facial burn sequelae, recipient sites, quantity of fat injected, aesthetic results are discussed. Patient age ranged from 21 to 55 years (average: 38). The mean follow-up of the study was 66 months (23-118). Patients received 7.5 (5-11) facial restorative surgeries before fat graft. Patients underwent two sessions of fat transfer, 33cc average per session. We did not report any complications. The clinical appearance, discussed by three surgeons and subjective patient feelings, after a 6-month follow-up period, suggests considerable improvement in the mimic features, skin texture, and thickness. The result is good in 86% of cases and acceptable in the other cases. Burns sequelae offer local conditions which justify special cannula can cross fibrosis and explaining the value of multiplying the sessions. Indications for lipostructure include four distinct nosological situations, sometimes combined. Lipostructure can restore a missing relief, filling a localized depression, reshape a lack of face volume or smooth a scarring skin. Fat graft seems to complete and improve the results of the standard surgical approach in burned face.

Influence of Platelet-Rich Plasma on the Histologic Characteristics of the Autologous Fat Graft to the Upper Lip of Rabbits

This study evaluated the influence of platelet-rich plasma (PRP) on the histologic characteristics of autologous fat grafts to the upper lip of rabbits. Nine New Zealand white rabbits were used. Eight of the rabbits underwent fat harvest from the groin fat pads using a modified Coleman technique. One side of the upper lip was infiltrated with autologous fat and the other side with fat and PRP. Four of the infiltrated rabbits were killed 8weeks after the lip augmentation, and the remaining four infiltrated rabbits plus one control case were killed 12weeks after the procedure. Coronal sections of both upper lips were analyzed microscopically to evaluate the quality of the fat graft, the inflammatory reaction, the presence of oil cysts, the degree of fibrosis, and the neovascularization. The infiltration of adipose tissue plus PRP presented less inflammatory reaction (p<0.05) and fewer oil cysts (p<0.05) than the infiltration of adipose tissue without PRP. The infiltration of fat tissue plus PRP generates a lower inflammatory reaction and less formation of oil cysts than the infiltration of isolated fat. Platelet-rich plasma increases the maintenance of the transplanted fat cells.

La réinjection première de graisse autologue en reconstruction mammaire

Prosthetic breast reconstruction is critical in the radiated breast. The main purpose of this study was to determine whether fat grafting prior to breast reconstruction could improve thoracic tissue trophicity enough to perform a simple prosthetic reconstruction, avoiding a flap procedure. A total of 25 patients who had undergone a modified radical mastectomy followed by radiotherapy were retrieved. Fat was injected according to Coleman's technique. Prosthetic reconstruction was performed three to six months after the fat grafting procedure. Reconstruction of the nipple-areola complex was performed 3 months after implant positioning. Median follow-up interval was two years. Patient satisfaction was ascertained with a self-assessment questionnaire. Three independent blinded physician observers judged preoperative and postoperative photographs to determine the quality of reconstruction. The mean refined fat injected volume was 160ml. In all cases except two, a unique fat grafting procedure was necessary. Prosthetic reconstruction was achieved in 23 cases. The technique failed in two cases and breast reconstruction was achieved by a latissimus dorsi flap with implant. During the follow-up interval, two complications occurred in two patients presenting with fat necrosis and oil cysts. The mean number of total surgical procedures was 2.5 per patient. Quality of reconstruction was judged as good by both physicians and patients. Autologous fat grafting in radiated tissue prior to breast reconstruction is a safe and reliable technique. In selected cases, a simple prosthetic reconstruction can be achieved avoiding a flap procedure.

Effects of a New Centrifugation Method on Adipose Cell Viability for Autologous Fat Grafting

The use of adipose tissue transfer in plastic and reconstructive surgery is not new and has been studied extensively. Due to different results with regard to adipose cell damage and the level of survival of the transferred tissue in clinical practice, the authors aimed to investigate the effects of centrifugation on fat aspirates to optimize the centrifugal force for fat transplantation and to obtain an increased number of intact adipose progenitor cells. The following different centrifugation forces were evaluated in vitro in terms of fat decantation: 3,000rpm (1,500×g), 1,300rpm (250×g), and 500rpm (50×g). Moreover, the density level, morphology of fat cells, cell viability, and progenitor cell number also were evaluated. Centrifugation leads to a good fat tissue density, with a significant number of progenitor cells, and efficiently removes the liquid portion. High centrifugal forces (at 3,000rpm) caused significant damage to fat cells with low cell viability, whereas very low centrifugal forces (at 500rpm) showed little effect on adipose tissue density, resembling fat decantation. Fat aspirates, withdrawn from 30 healthy donors in vivo, were centrifuged at different rotations per minute (rpm), as follows. For the 10 patients in group A, Coleman's technique was used with a centrifugation of the aspirated fat at 3,000rpm (1,500×g) for 3min. For the 10 patients in group B, the authors' technique was used, with centrifugation of the aspirated fat at 1,300rpm (250×g) for 5min. For the 10 patients in group C, simple decantation of fat was used. In conclusion, a centrifugal force of 1,300rpm resulted in better density of adipose tissue, with good cell viability and increased ability to preserve a significant number of progenitor cells.

Fat Graft before Breast Reconstruction by Latissimus Dorsi

Sir: Delayed breast reconstruction by means of latissimus dorsi musculocutaneous flap and implant is a common procedure after mastectomy and radiotherapy, especially in patients at high risk for complications, because of the reliable vascularity associated with this flap.1 However, in such patients, we have observed necrosis of the irradiated skin around the flap (Fig. 1).Fig. 1.: Necrosis of the soft tissues beneath the latissimus dorsi flap 1 month after breast reconstruction: the underlying implant is exposed. Note that the flap survived.Fat grafting is a routine procedure for refinements after breast reconstruction and has been shown to be a powerful regenerative treatment for irradiated2 and injured tissues, improving skin quality, vascularity, scar retraction,3 ulcers,4 and pain.5 For these reasons, we decided to perform fat grafting at the mastectomy irradiated area before breast reconstruction by latissimus dorsi musculocutaneous flap. From March of 2007 to January of 2009, we enrolled five patients who were candidates for delayed breast reconstruction by means of latissimus dorsi musculocutaneous flap surgery. The patients had a mean age of 49.2 years (range, 39 to 67 years). All of them were smokers and one was obese and diabetic. They had undergone mastectomy, chemotherapy, and radiotherapy 3 to 10 months previously and presented poor thickness, vascularization, and tissue quality of the recipient site. All patients underwent only one fat graft under continuous intravenous fentanyl infusion associated with local anesthesia. After tumescent infiltration, liposuction of the subumbilical area was performed. An adipose tissue sample of approximately 100 ml was obtained and processed following Coleman's technique. A volume of 46 to 60 ml (average, 54.8 ml) was injected using an 18-gauge angiographic needle with a snap-on wing at the dermal-subdermal junction of the irradiated, retracted mastectomy area. No complications occurred. Three months after fat grafting, we performed breast reconstruction by means of latissimus dorsi musculocutaneous flap and implant placement. We verified that skin texture, softness, and elasticity of the irradiated mastectomy area had improved dramatically after fat grafting. The skin paddle was oriented horizontally. Suction drains were placed at the donor and recipient sites and removed 3 to 5 days later. All patients were followed up at 2 weeks, 1 month, 3 months, and 6 months after surgery. No necrosis or dehiscence occurred. The final outcome was good and all patients were satisfied (Fig. 2).Fig. 2.: Postoperative view 1 month after breast reconstruction by latissimus dorsi flap and implant. Fat grafting had been performed 3 months before.Our preliminary experience shows that fat grafting is an additional tool with which to prevent surrounding skin necrosis when it is expected because of high-risk local factors and systemic conditions. We compared these data with the results of six breast reconstructions using the latissimus dorsi musculocutaneous flap performed from 2004 to 2006 without previous fat grafting: this complication had occurred in three patients, all of whom were smokers and had undergone radiotherapy and chemotherapy. Adipose tissue is easily harvested, with low morbidity. The regenerative properties of fat graft, vascular improvement, and architectural remodeling of soft tissues could play a role in preparing an irradiated site for major surgery. Not only mesenchymal stem cells from the stromal fraction of harvested fat2 but also molecular components and the surrounding microenvironment are presumed to be involved. DISCLOSURE The authors have no financial interests or commercial associations to disclose. There was no funding support for this study. Federico Villani, M.D. Fabio Caviggioli, M.D. Francesco Klinger, M.D. Luca Maione, M.D. Marco Klinger, M.D. Cattedra di Chirurgia Plastica Università degli Studi di Milano U.O. Chirurgia Plastica 2 IRCCS Istituto Clinico Humanitas Rozzano, Italy

The Fat Trap: A Simple Method for Harvesting Large Amounts of Adipose Tissue during Liposuction

Sir: Autologous fat grafting is a technique that is increasingly used in plastic and reconstructive surgery. When large amounts of adipose tissue are needed, such as for breast reconstruction, syringe aspiration can be tedious and time consuming. We describe here an original and simple technique for harvesting large volumes of adipose tissue. We use an 800-ml sterile drainage bottle connected on one end to the liposuction cannula (4 or 6 mm) and on the other end to the aspirating device, as shown in Figure 1.Fig. 1.: The fat trap with an 800-cc drainage bottle.The adipose tissue is collected in the drainage bottle, which serves as a “fat trap.” Once liposuction is finished, the fatty tissue is transferred into 10-ml syringes. Centrifugation of the sample is performed as described in Coleman's technique.1 Reinjection is achieved using 3-ml syringes. We used this technique in more than 200 cases of autologous fat grafting after breast reconstruction with implants or flaps. The mean volume of fat harvested was 400 cc (range, 200 to 1000 cc) and the mean volume of fat reinjected was 150 cc (range, 40 to 470 cc). We have been using this fat trap for more than 3 years for breast reconstruction. With a median follow-up of 12 months, we did not notice any increase in fat resorption compared with the standard syringe fat-harvesting technique. However, there are still controversies regarding the best way to harvest and reinject adipocytes. For Pu et al., although liposuction does not damage the histologic structure of the fatty tissue, it reduces the viability and cellular function of adipocytes.2 Conversely, for Sommer and Sattler, adipocytes survive equally well after liposuction or needle aspiration.3 Adanali et al. stated that liposuction does not damage fat samples if the vacuum used is lower than 700 mmHg.4 Moreover, Park et al. have shown that even if liposuction causes more initial damage to the fatty tissue, it allows better long-term viability because of increased cell proliferation.5 Although the Coleman technique is suitable when small volumes of fat tissue are needed (e.g., for facial rejuvenation), liposuction using our fat trap allows for the harvesting of important amounts of fatty tissue and reduces the duration of surgery. This is particularly interesting when important volumes have to be reconstructed using adipocytes. Furthermore, our technique is simple and does not require a specific device because 800-ml drainage bottles can be found in every surgical unit. Liposuction using the fat trap is a simple technique that is helpful when large amounts of adipose tissue are needed in reconstructive surgery. A prospective evaluation of our autologous fat grafting cases is currently ongoing and will allow us to compare the fat-resorption rate of this technique to that of the Coleman technique. DISCLOSURE The authors have no conflicts of interest to disclose. Tarik Ihrai, M.D. Krishna B. Clough, M.D. Claude Nos, M.D. Isabelle Sarfati, M.D. Paris Breast Center Paris, France