文献 progenitor-enriched adipose tissue transplantation as rescue

IORIGINAL ARTICLEProgenitor-Enriched Adipose Tissue Transplantationas Rescue for Breast Implant ComplicationsKotaro Yoshimura, MD,* Yuko Asano, MD, Noriyuki Aoi, MD,*Masakazu Kurita, MD, Yoshio Oshima, MD, Katsujiro Sato, MD,Keita Inoue, MD,* Hirotaka Suga, MD,* Hitomi Eto, MD,*Harunosuke Kato, MD,* and Kiyonori Harii, MD*Department of Plastic Surgery, University of Tokyo School of Medicine, Bunkyo-ku, Tokyo, Japan;Cellport Clinic Yokohama, Minami-nakadori, Yokohama, Kanagawa, Japan; and Department ofPlastic Surgery, Kyorin University School of Medicine, Mitaka-shi, Tokyo, Japann Abstract: Breast enhancement with articial implants is one of the most frequently performed cosmetic surgeries butis associated with various complications, such as capsular contracture, that lead to implant removal or replacement at arelatively high rate. For replacement, we used transplantation of progenitor-supplemented adipose tissue (cell-assistedlipotransfer; CAL) in 15 patients. The stromal vascular fraction containing adipose tissue progenitor cells obtained fromliposuction aspirates was used to enrich for progenitor cells in the graft. Overall, clinical results were very satisfactory, andno major abnormalities were seen on magnetic resonance imaging or mammogram after 12 months. Postoperative atrophyof injected fat was minimal and did not change substantially after 2 months. Surviving fat volume at 12 months was155 50 mL (Right; mean SD) and 143 80 mL (Left) following lipoinjection from an initial mean of 264 mL. Thesepreliminary results suggest that CAL is a suitable methodology for the replacement of breast implants. nKey Words: adipose-derived stem cells, autologous fat transplantation, breast prosthesis, cell therapy, complicationsmplantation of articial prostheses is a standardmethod of breast augmentation and is the most fre-quently performed cosmetic surgical procedure in US(approximately 347,000 cases in 2007) (1). However,complications derived from the foreign body, such ascapsular contracture, malposition, implant rupture,and infection, occur at a relatively high rate (1020%)(25) and frequently result in implant removal(approximately 27,000 cases in 2007) (1) or replace-ment of breast implants. While it is unlikely that theimplant itself induces malignant changes, the presenceof the implant could affect the rate of malignancy byreducing breast tissue visualization in the mammo-gram (6). Furthermore, there is potential for rupturewhen pressure is exerted on the implant during mam-mography, and for this reason, hospitals in JapanAddress correspondence and reprint requests to: Kotaro Yoshimura, MD,Department of Plastic Surgery, University of Tokyo School of Medicine, 7-3-1,Hongo, Bunkyo-Ku, Tokyo 113-8655, Japan, or e-mail: yoshimura-plah.u-tokyo.ac.jp.DOI: 10.1111/j.1524-4741.2009.00873.x2009 Wiley Periodicals, Inc., 1075-122X/09The Breast Journal, Volume 16 Number 2, 2010 169175reject women who have breast implants to undergomammography as a part of annual social health exam-inations.The use of autologous fat tissue as an alternativeimplant material for breast augmentation has notgained acceptance because of a lack of consensus onits safety and concern that the development of micro-calcications within the transplanted tissue could com-plicate mammogram evaluation (7). However,autologous fat tissue was recently re-evaluated as analternative to articial implants for breast augmenta-tion or reconstruction (710), possibly reectingrecent technical advances in autologous fat transferand the radiological detection of breast cancer.Although autologous fat transplantation offers manyadvantages, such as the lack of scarring and complica-tions associated with foreign materials, the unpredict-ability and a low rate of graft survival because ofpartial necrosis are issues that remain to be resolved.To address these problems, we developed a novelstrategy called cell-assisted lipotransfer (CAL; Fig. 1).CAL was designed based on the nding that aspiratedfat tissue contains many fewer vessels and adipose170 yoshimura et al.(a)(b)progenitor cells than does intact fat tissue (11) and onour hypothesis that the ratio of progenitor cells toadult cells (adipocytes) is a critical factor for adiposetissue turnover as well as preservation of the survivingadipose tissue volume. The deciency of progenitorsin aspirated fat tissue may explain the progressiveatrophy of transplanted aspirated fat tissue that occursduring the rst 6 months of post-transplantation (11).In a clinical trial of CAL, the stromal vascular fraction(SVF) comprising 1040% adipose progenitor cells(12,13) was freshly isolated from aspirated fat tissuevia collagenase digestion and added to graft materials,converting relatively progenitor-poor fat tissue intoprogenitor-rich tissue.MATERIALS AND METHODSIn this preliminary report, we analyzed the out-comes of 15 female patients who underwent CAL forimmediate breast augmentation after breast implantremoval. Patients participating in the trial did soFigure 1. Procedure schemes. (a) Conceptof cell-assisted lipotransfer (CAL). Relativelyprogenitor-poor aspirated fat tissue is con-verted to progenitor-rich fat tissue by supple-mentation with the stromal vascular fraction(SVF) isolated from one-half of the aspiratedfat sample. SVF cells are attached to theaspirated fat tissue, which acts a scaffold inthis strategy. (b) Time course for CAL breastreplacement surgery. The operation beginswith the harvesting of fat tissue for the isola-tion of SVF cells. While the cell isolation pro-cess is performed in a cell-processing room,implant removal and liposuction for graftmaterial are performed in the operatingroom. After adding isolated the SVF to thecentrifuged fat tissue, the mixture is injectedinto the breast. The entire procedure takesapproximately 4 hours to complete.under informed consent approved by the individualreview board. The concept and time course of theCAL procedure are shown in Figs. 1 and 2.Surgical TechniquesThe liposuction site was inltrated with salinesolution containing diluted epinephrine (0.0001%)while the patient was under general anesthesia, andthen adipose tissue was suctioned using a 2.5-mm(inner diameter) cannula and a conventional liposuc-tion machine. About half of the lipoaspirate wasused for SVF isolation. The SVF was isolated fromboth the adipose and uid portions of the liposuc-tion aspirate as described previously (12); the cellprocessing procedure took about 90 minutes. Thecell composition of the SVF was described previously(12,13). During processing, the other half of the lipo-aspirate was harvested as graft material. Breastimplants were removed through a periareolar inci-sion, which was placed at the caudal third of theareola margin.(a)(b)Progenitor-Enriched Adipose Tissue Transplantation as Rescue for Breast Implant Complications 171was a 10-cc LeVeen inator (Boston ScienticCorp., Natick, MA) or our original syringe (20 mL),which were used because both are screw-type syringeswith threaded plungers and have threaded connectionsthat t both the connecting tube and the needle,allowing for precise control during the injection. Twosyringes were used to minimize procedure time; whileone syringe was being used for an injection, the otherwas lled with the graft material in preparation forthe next injection. A 16- or 18-gauge sharp needle(150-mm long) was used for lipoinjection. The needlewas inserted into several different layers and in differ-ent directions, and was continuously and graduallyretracted as the plunger was advanced. Lipoinjectionwas initiated at the deepest layer under the implantcapsule and completed with injection into the mostsupercial subcutaneous layer.In the deepest layer, the operator took care toinsert and maintain the needle horizontally (parallel tothe body) to avoid damaging the pleura and causing apneumothorax. The operator inserted a nger intothe implant capsule, placed it on the bottom of thecapsule, and determined the location of the injectionneedle.When the original implants had been inserted underthe pectoralis muscle, we often found the implant cap-sule adhered to the ribs. In these cases, the needle wasinserted from the lateral margin of the breast and theneedle tip was slid medially along a rib with greatFigure 2. Schematic illustration of the injection method. (a) Usinga long needle attached to a syringe with a threaded plunger, pro-genitor-supplemented fat tissue is injected while the needle is con-tinuously withdrawn. The fat tissue is injected as a small aliquot ora thin string into layers other than the mammary gland and capsu-lar cavity. While injecting, the ngers are inserted through a peri-areolar skin incision into the implant capsule to determine thelocation of the needle tip. Details of the surgical procedure aredescribed below. (b) The needle is inserted either through a peri-areolar incision or at one of two points in the infra-mammary fold.The needle is aimed in various directions and into different planesto achieve a diffuse distribution.The second half of the lipoaspirate was centrifugedat 700 g for 3 minutes without washing. After centri-fugation, the oil and uid portions were discarded,while the adipose portion was collected in a coveredmetal jar (500 mL) and placed in an ice water bath.The freshly isolated SVF was added to the centrifugedfat tissue and, after gentle mixing and a 10- to 15-minute incubation to achieve cell adhesion to the cen-trifuged fat tissue, the cell-supplemented fat tissue wasplaced into the injection syringe. The injection syringecare. After injections along the ribs, the capsule wasdetached from the ribs and fat graft injection into thespace under the capsule continued; injections werealso made from a point on the inamammary fold.Lipoinjection between the capsule and the skin wereperformed from the same two points and from theperiareolar incision. This technique was used to obtaina diffuse distribution of the graft material; injectioninto the mammary glands or the capsular cavity wasnot performed. Finally, the capsular cavity waswashed with saline and the periareolar incision wasclosed. After the surgery, the breasts were held inposition with a brassier and massage of the breastswas prohibited for 3 months.Pre- and postoperative evaluations included mam-mography, magnetic resonance imaging (MRI), pho-tography, videography, and three-dimensional (3D)measurements (Sppd-3E, Kiisya Ltd., Tokyo, Japan)that enabled volumetric evaluation of the breastmound with the patient in a standing position(Fig. 3).172 yoshimura et al.(a)(b)RESULTSCell-assisted lipotransfer was successful in all cases;8 of the 15 patients were followed for more than12 months (at the time of this report) and the maxi-mum follow-up period was 18 months. Patient dataand data regarding removed implants and postopera-tive breast measurements are summarized in Table 1.The 3D measurements showed that the transplantedadipose tissue was gradually absorbed during the rsttwo postoperative months but that the breast volumeshowed changed minimally thereafter. The survivingfat volume was 155 50 mL (Right; mean SD) and143 80 mL (Left) at 12 months (n = 6: removedimplant volume was not available for two patients;Table 1. Summary of Patient Data(c)Number of casesGender (f m)Age (years)BMI1515 037.1 12.519.5 1.4Removed implants (ruptured)Saline (n = 4)Silicon (n = 22)Hydrogel (n = 4)Size of removed implants(mL) (N A for six rupturedimplants)Right (n = 15)2 (0)11 (5)2 (1)Right (n = 12)201 53Left (n = 15)2 (0)11 (4)2 (1)Left (n = 12)196 46Site of liposuction Thighs, 5 Thighs and abdomen, 10Figure 3. The three-dimensional measurement system. (a) Per-pendicular striped lights are projected onto the body while thepatient is in a standing position (left panel). Three points that donot usually shift after breast augmentation (shoulder, suprasternalnotch, and xiphoid process) are plotted to designate a standardplane. Photos are taken using a stereo-type digital camera. Cus-tom-made software (Kiisya Ltd., Tokyo, Japan) calculates the pro-Right (n = 15) Left (n = 15)Volume of injection (mL) 268 29 259 39Right LeftSurviving fat volume (= changes in breast volume + removedimplant size) (mL)1 week (n = 10) 274 68 264 771 month (n = 8) 186 57 206 662 months (n = 8) 187 72 190 553 months (n = 10) 172 57 182 666 months (n = 10) 157 58 150 529 months (n = 6) 143 32 160 6812 months (n = 6) 155 50 143 80jection of the skin surface and draws contour lines (right panel).Then, the breast mound volume is calculated and recorded, alongwith the highest projection of the mound. (b) Representative datausing the three-dimensional measurement system before (leftpanel) and 6 months after the surgery (right panel). Case 3 (seealso Fig. 6) had 220-mL silicone gel implants before CAL. At 6months after CAL, the breast projection and breast volumedecreased by 11.4 mm and 32.4 mL, respectively, but the breastcontour became more natural. (c) Sequential changes in the sur-Changes in breast projection (mm)1 week (n = 10)1 month (n = 8)2 months (n = 8)3 months (n = 10)6 months (n = 10)9 months (n = 6)12 months (n = 6)Right Left)1.5 6.1 1.4 6.1)3.5 7.5 )3.6 5.5)5.3 4.6 )4.2 5.4)4.5 5.2 )6.3 6.0)8.3 3.7 )6.5 5.0)10.5 4.8 )6.2 7.3)9.2 5.4 )7.9 7.6viving fat volume. The red line shows the average and SD of datacollected at each time point (as listed in Table 1), while other linesreect individual data (n = 10). Surviving fat volume was calculatedas (postoperative breast volume) ) (preoperative breast volume) +(removed implant volume).Removed implants are listed according to the type of substance they contained. Elevenof 30 implants were found to be ruptured at the time of removal and implant size wasunrecognizable in six of these implants. Three-dimensional measurement of the breastswas accepted by and performed for 13 of 15 patients. Because of the unknown volumeof ruptured implants, surviving fat volume was not calculated for 3 of the 13 patients; 12-month data were obtained for six of eight patients who were followed for more than12 months because of unavailability of implant volume.Progenitor-Enriched Adipose Tissue Transplantation as Rescue for Breast Implant Complications 173Figure 4. Clinical and radiological views of Case 1. Preoperative(left panels) and postoperative (right panels) views at 12 months.Clinical views showed capsular contracture and upward displace-ment of the left implant before surgery (top, left), while the breastshad a natural and symmetrical appearance at 12 months (top,right). T1-weighted MRI (middle, left, and right) revealed that thetransplanted adipose tissue survived and formed thick layersaround and under the mammary gland at 12 months. Mammo-grams showed that neither implant was ruptured before surgery(bottom, left) and that no calcication or other abnormal signs werevisible in either breast at 12 months (bottom, right). Augmentedbreast mounds maintained sufcient breast volume even afterimplant removal, and were naturally soft without any subcutaneousindurations (see also Video S1).Table 1, Fig. 3b,c), meaning that the graft take rangedfrom approximately 40% to 80%. Breast projectiondecreased by 9.2 5.4 mm (Right) and 7.9 7.6 mm(Left) at 12 months when compared with beforeimplant removal. All patients showed natural breastsoftness without any palpable nodules at 12 monthsand all patients were satised with the texture, soft-ness, contour, and symmetry of their breasts, as wellas the absence of foreign materials. Pre- and postopera-tive photographs of representative patients, as well astheir MRIs and mammograms, are shown in Figs. 47;videos of the same patients are available as SupportingInformation online Videos S1S4. No serious side-effects have been observed in the 15 patients; no cystformation (5 mm) or micro-calcications weredetected at 12 months (n = 8) by MRI or mammogra-phy. MRI analyses showed that the fatty layersaround the mammary glands were substantiallythicker at 12 months (n = 8) when compared withbaseline (Figs. 47).Figure 5. Clinical and radiological views of Case 2. Preoperative(left panel) and postoperative views at 12 months (right panel).Clinical views show capsular contractures and displacement of theright implant before surgery (top, left), while the breasts were sym-metrical and had a natural appearance at 12 months (top, right).Mammograms showed that both implants were ruptured beforesurgery (bottom, left), and that no abnormal signs were present at12 months (bottom, right). Augmented breast mounds were softand natural-appearing without injection scars or subcutaneousindurations (see also Video S2).DISCUSSIONTissue-specic progenitor cells in adipose tissue candifferentiate into various cell lineages (14,15). Theseprogenitors, called adipose-derived stem stromal cells(ASCs), are expected to become valuable tools in awide range of cell-based therapies (15). ASCs arebelieved to act as progenitors of adipocytes and vascu-lar cells (16), reside between adipocytes or in theextracellular matrix especially around vessels, andcontribute to the turnover of adipose tissue (17),which is known to be very slow in humans (210 years) (17,18). The therapeutic concept of CALwas described in our previous pre-clinical (11) andclinical studies (9,19); we found that aspirated fat hasapproximately half the number of ASCs as excisedwhole fat tissue (11). We hypothesized that the rela-tive deciency of tissue-specic progenitors in aspi-rated fat tissue might contribute to the low survivalrate and long-term atrophy of transplanted fat tissue,as was partially conrmed in animal studies(11,20,21). In the CAL strategy, the progenitor decitwas compensated for by supplementation with ASCsisolated from a separate volume of aspirated fattissue. Speculated roles of ASCs in CAL are: (a) differ-entiate into adipocytes and contribute