Tissue Expansion Research Articles

What did we catch? Predictors of infection after tissue expander–based breast reconstruction in a safety-net system

BackgroundInfection is a common complication following tissue expander (TE)–based breast reconstruction. Few studies have examined risk factors specifically in the unique populations encountered at safety-net hospitals. The purpose of this study was to identify predictors of TE infection at Harris Health safety-net hospitals, which serve the third most populous county in the United States. MethodsA retrospective review was performed to evaluate women over the age of 18 years who underwent TE placement at two safety-net hospitals from October 2015 to November 2022. Demographic information, medical history, operative details, and postoperative course were recorded for each individual TE. The primary outcome was TE infection, for which univariate and multivariate analysis was conducted. The secondary outcome was the time to onset of TE infection, for which a Kaplan-Meier analysis was undertaken. ResultsThere were 279 patients, totaling 372 breasts, meeting the inclusion criteria. The TE infection rate was 23%. Increased body mass index (BMI), diabetes, use of acellular dermal matrix (ADM), and prolonged surgical drain use were all significantly associated with TE infection in univariate and multivariate analysis. Similarly, BMI ≥30 kg/m2, diabetes, and ADM use were also associated with earlier onset of TE infection. ConclusionsThis study demonstrated similar TE infection rates at our safety-net hospitals compared with previously reported literature. To optimize the quality of care for patients in safety-net institutions, these risk factors must be addressed in the context of the unique challenges encountered in these settings.

Patient-Reported Outcomes and Complication Profiles of Implant-Based Breast Reconstruction in Patients With Postmastectomy Radiation Therapy.

This study aims to investigate the patient-reported outcomes (PROs) and complications of distinct implant-based breast reconstruction modality for patients with postmastectomy radiation therapy (PMRT). A retrospective review was conducted on breast cancer patients with stage II-III disease who performed implant-based breast reconstruction following with PMRT between September 2016 and April 2022. The patients were categorized into two matched groups: (1) patients receiving prepectoral breast reconstruction (PBR) or (2) subpectoral breast reconstruction (SBR) followed by PMRT. Following reconstruction, the patients were further compared for PMRT with the tissue expander (PMRT-TE) versus PMRT with permanent implant (PMRT-PI). PROs were measured with BREAST-Q questionnaire. Early and late complications were recorded and analyzed. A total of 55 eligible patients were recruited. Patients who underwent PBR reported significantly higher satisfaction with breasts scores (P = 0.003) compared with the SBR group. The PMRT-TE group had higher satisfaction with breasts (P = 0.001) but lower physical well-being (P = 0.029) scores compared with PMRT-PI group. Moreover, patients in SBR cohort had a higher risk of capsular contracture (Baker grade III or IV) (20.5% vs 6.3%) and implant dislocation (48.7% vs 12.5%) than patients in PBR cohort. Patients in PMRT-PI group had a slightly higher rate of capsular contracture (Baker grade III or IV) than PMRT-TE group (20.8% vs 12.9%). PBR was associated with lower rates of late complications, especially for implant dislocation, and higher satisfaction with breasts scores compared to SBR. In addition, compared to PMRT-TE with PMRT-PI, patients in PMRT-TE cohort reported superior PROs of satisfaction with breasts.

Acellular Dermal Matrix-Assisted, Prosthesis-Based Breast Reconstruction: A Comparison of SurgiMend PRS, AlloDerm, and DermACELL.

Acellular dermal matrices (ADMs) are frequently employed in immediate prosthesis-based breast reconstruction (iPBR) to provide structural support. Despite differences in ADM derivatives, few studies directly compare their outcomes in the setting of iPBR. We sought to conduct a large head-to-head study comparing 3 ADMs used across our institution. A multicenter retrospective review of patients undergoing iPBR with SurgiMend PRS (fetal bovine-derived; Integra Lifesciences, Princeton, NJ), AlloDerm (human-derived; LifeCell Corp, Bridgewater, NJ), or DermACELL (human-derived; Stryker Corp, Kalamazoo, MI) between January 2014 to July 2022 was performed. Primary outcomes included rates of unplanned explantation and total reconstructive failure. Secondary outcomes included 90-day postoperative complications and long-term rates of capsular contracture development. A total of 738 patients (1228 breasts) underwent iPBR during the study period; 405 patients received DermACELL (54.9%), 231 received AlloDerm (31.3%), and 102 received SurgiMend PRS (13.8%). Rates of short-term complications, total reconstruction failure, reoperation within 90 days, capsular contracture, and unplanned explantation were comparable. These findings remained true upon multivariate analysis accounting for baseline differences between cohorts, whereby ADM type was not an independent predictor of any outcome of interest. Conversely, factors such as body mass index, diabetes mellitus, smoking history, neoadjuvant and adjuvant chemotherapy, adjuvant radiation, skin-sparing mastectomy, Wise pattern and periareolar incisions, use of tissue expanders, and a subpectoral plane of insertion were significant predictors of postoperative complications. Low rates of complications support the equivalency of fetal bovine and human-derived ADMs in iPBR. Patient characteristics and operative approach are likely more predictive of postoperative outcomes than ADM derivative alone.

Chyle Leak Management in the Setting of Tissue Expander Breast Reconstruction with Acellular Dermal Matrix: Case Series and Literature Review.

Chylous leakage is a rare surgical complication most frequently encountered following operations involving the neck and thorax. Even more rare are axillary chyle leaks secondary to breast cancer involving the axillary lymph nodes. Anatomic variability in the termination of the thoracic duct may play a role in the susceptibility some individuals may have to this type of leakage. There is no consensus on the definitive management of these complications, especially in the context of breast reconstruction. Here, we report our experience in the management of chylous leakage in three patients who underwent left axillary lymph node dissection and immediate breast reconstruction with the use of tissue expanders and acellular dermal matrix. Descriptions of each case are followed by a review of the relevant literature. We also present an original treatment algorithm. Two of three patients with suspected chylous leakage secondary to intraoperative injury to the axillary region underwent definitive diagnosis by clinical examination and drain fluid triglyceride analysis, followed by conservative management with a low-fat diet. The third patient was diagnosed clinically with no fluid analysis. All leakages resolved through conservative means, with no need to return to the operating room for surgical exploration and repair. Based on our experience, we believe that patients with suspected chylous leakage secondary to axillary lymph node dissection in the context of breast reconstruction can be safely and effectively managed by conservative management in the acute postoperative period. If these measures are insufficient, surgical management may be necessary.

To acellular dermal matrix or not to acellular dermal matrix?-outcomes of pre-pectoral prosthetic reconstruction after nipple-sparing mastectomy with and without acellular dermal matrix.

Acellular dermal matrix (ADM) has been the go-to biomaterial in post-mastectomy breast reconstruction, particularly in pre-pectoral reconstruction. ADM is thought to decrease capsular contracture, control the pocket, and increase soft tissue, but may yield more complications. This study evaluated whether ADM is even needed. All patients undergoing immediate breast reconstruction with pre-pectoral tissue expander (TE) or direct-to-implant (DTI) after nipple-sparing mastectomy (NSM) by the senior author between April 2013 and January 2021, were included in this study. Cohorts were stratified into breasts with ADM or no-ADM. Complications within 30 days post-operatively were analyzed. A total of 115 pre-pectoral reconstructions were performed in 66 patients. ADM was applied to 75 breasts. TEs were used in 80 breasts and DTI in 35 breasts. Controlling for implant type, breasts with ADM exhibited more nipple necrosis (28.0% vs. 10.0%, P=0.02). Controlling for ADM status, DTI compared to TE was associated with less necrosis of the nipple (11.4% vs. 26.3%, P=0.04), implant loss (5.7% vs. 38.8%, P=0.004), and surgery for any complication (14.3% vs. 27.5%, P=0.04). Outcomes of prosthetic reconstructions with ADM and no-ADM were similar. DTI reconstruction was associated with less complications, which was likely due to intraoperative bias and placement of TEs more often in breasts with perceived poorer vascularity.

Long-term Implications of Cosmetic Breast Surgeries on Subsequent Breast Reconstruction.

Cosmetic breast surgeries such as augmentation, mastopexy, and reduction are common aesthetic medical procedures for enhancing physical appearance. Despite their popularity, the influence of these surgeries on subsequent breast reconstruction for cancer patients remains underexplored. In this study we sought to investigate the effects of previous cosmetic breast surgeries on the outcomes of breast reconstruction. A retrospective chart review was conducted from January 2011 to May 2023. This analysis compared patients with histories of implant augmentation, breast reduction, mastopexy, and augmentation mastopexy with those receiving reconstruction without any cosmetic surgery history. Demographics, comorbidities, complications, revisions, and BREAST-Q surveys were collected. Statistical analysis was performed with SPSS, with significance set at P < .05. The study included 124 patients (50 autologous, 74 implant) with a history of cosmetic breast surgery (102 implant augmentations, 17 breast reductions, 5 mastopexies, and 9 augmentation mastopexies). They were analyzed in comparison with 1307 patients (683 autologous, 624 implant) without previous cosmetic breast surgery. Patients with previous cosmetic surgeries showed a higher incidence of hematoma with tissue expander placement. A preference for implant-based reconstruction was more common among patients with an augmentation history (P < .001), whereas autologous reconstruction was more common in those with a history of breast reduction (P = .047). Patients with a history of breast augmentation had on average significantly more breast revisions (P < .05). In this study we demonstrate a significantly higher hematoma rate and number of revisions in patients with previous cosmetic breast surgery when compared to patients without a history of cosmetic surgery. Furthermore, we suggest that types of cosmetic breast surgery influence the decision-making process regarding implant vs autologous reconstruction.

Osteoprotegerin mediates adipogenesis in obesity

IntroductionAdipogenesis, the process of white adipose tissue expansion, plays a critical role in the development of obesity. Osteoprotegerin (OPG), known for its role in bone metabolism regulation, emerges as a potential regulator in mediating adipogenesis during obesity onset. ObjectivesThis study aims to elucidate the involvement of OPG in adipogenesis during the early phases of diet-induced obesity and explore its therapeutic potential in obesity management. MethodsUsing a diet-induced obesity model, we investigated OPG expression patterns in adipocytes and explored the mechanisms underlying its involvement in adipogenesis. We also assessed the effects of targeted silencing of OPG and recombinant OPG administration on obesity progression and insulin resistance. Additionally, the impact of electroacupuncture treatment on OPG levels and obesity management was evaluated in both animal models and human participants. ResultsOPG expression was prominently activated in adipocytes of white adipose tissues during the early phase of diet-induced obesity. Hyperlipidemia induced Cbfa1-dependent OPG transcription, initiating and promoting adipogenesis, leading to cell-size expansion and lipid storage. Intracellular OPG physically bound to RAR and released the PPARɤ/RXR complex, activating adipogenesis-associated gene expression. Targeted silencing of OPG suppressed obesity development, while recombinant OPG administration promoted disease progression and insulin resistance in obese mice. Electroacupuncture treatment suppressed obesity development in an OPG-dependent manner and improved obesity parameters in obese human participants. ConclusionOPG emerges as a key regulator in mediating adipogenesis during obesity development. Targeting OPG holds promise for the prevention and treatment of obesity, as evidenced by the efficacy of electroacupuncture treatment in modulating OPG levels and managing obesity-related outcomes.

Impact of Implant Exchange Timing after Post-Mastectomy Radiation in Immediate Tissue Expander Breast Reconstruction: A Systematic Review.

The use of post-mastectomy radiation therapy (PMRT) in the setting of immediate two-stage breast reconstruction is becoming increasingly widespread. However, the timeframe of tissue expander exchange for permanent implant placement following PMRT is not well-defined, and it remains unclear what time interval optimizes surgical outcomes and patient satisfaction. A systematic review conducted in accordance with PRISMA 2020 was completed. PubMed, Embase, Scopus, and Cochrane databases were searched under keywords pertaining to concepts of tissue expander breast reconstruction and PMRT. Inclusion criteria encompassed primary articles on tissue expander breast reconstruction with adjuvant radiation therapy reporting timing of exchange to permanent implant following radiation and surgical outcomes. Of the initial 1,259 publications, 15 studies met our inclusion criteria, and 11 studies had granular enough data to use for pooled analysis. Implant exchange less than 6 months after PMRT was found to be associated with increased incidence of wound dehiscence (17.12% vs 3.64%, p<0.001) and hematoma (25% vs 2.59%, p<0.001) compared to exchange after 6 months. There was no significant difference in incidence of SSI, seroma, capsular contracture, and reconstructive failure. Expander to implant exchange at less than 6 months is associated with a higher incidence of wound dehiscence and hematoma formation but does not increase the risk of reconstruction failure. The limited research on ideal timing prompts further investigation to optimize surgical outcomes for the increasing patient population undergoing PMRT and immediate two-staged breast reconstruction.

In Vivo Release of Zafirlukast from Electrospun Polyisobutylene-Based Fiber Mats to Reduce Capsular Contracture of Silicone Breast Prostheses.

Silicone rubber tissue expanders and breast implants are associated with chronic inflammation, leading to the formation of fibrous capsules. If the inflammation is left untreated, the fibrous capsules can become hard and brittle and lead to formation of capsular contracture. When capsular contracture occurs, implant failure and reoperation is unavoidable. Fibrous capsule formation to medical grade silicone rubber breast implants and polyisobutylene-based electrospun fiber mats attached to silicone rubber with and without an anti-inflammatory therapeutic were compared. A linear polyisobutylene (PIB)-based thermoplastic elastomer is currently applied as a polymer coating for drug release on coronary stents to reduce restenosis. Recent work has created a drug releasing electrospun fiber mat from PIB-based materials. Important to this study, poly(alloocimene-b-isobutylene-b-alloocimene) (AIBA) was electrospun with zafirlukast (ZAF). ZAF is an anti-inflammatory drug that is able to reduce capsule formation and complications to silicone breast implants. Fiber mats are advantageous for local drug delivery because of their high porosity and surface area for drug release. The chief hypothesis was that local release of ZAF from AIBA would lower inflammatory signaling and resulting capsular formation after 90 days in vivo. Electrospun AIBA mats locally released ZAF, lowering inflammation and fibrous capsule development compared to medical grade silicone rubber. Locally and orally released ZAF led to similar results, but the former had much lower concentration that highlights local delivery's therapeutic potential. Released ZAF from AIBA fiber mats mitigated inflammation and serves as an alternative to existing clinical approaches.

Subdiffraction Imaging of Cleared and Expanded Large-Scale Tissues.

The quest for high spatial resolution in molecular identification is critical across various domains, including physiology, pathology, and pharmaceutical research. Super-resolution microscopy has made strides by surpassing the Abbe diffraction limit, but it relies on sophisticated equipment and is limited by the sample size to handle. Expansion microscopy, an emerging technique, has broadened the scope of subdiffraction imaging. It chemically preserves tissues at a large scale and physically enlarges them 4-20 times linearly, enabling super-resolution observation. This review begins by exploring the foundational concepts of tissue clearing and the latest methodologies in the field. It then delves into the core tenets of expansion microscopy, covering a range of protocols. The review spotlights advancements in enhancing resolution, improving labeling efficiency, and ensuring isotropic tissue expansion. Finally, the review offers insights into the prospective evolution of expansion microscopy. It emphasizes the potential role of machine learning in refining image quality and in the autonomous extraction of data, which could revolutionize the way we visualize and understand biological tissues.

Aesthetic Reconstruction of the Sequelae of Large Facial Involuted Infantile Hemangioma with Tissue Expanders.

Large involuted infantile hemangioma remains a challenge in facial reconstruction. The characteristic fibrofatty residuum and multiple subunits/tissues involvement contribute significantly to the difficulty of surgical management. Tissue expander plays an important role in facial reconstruction, allowing plastic surgeons to repair skin damaged by both congenital and acquired defects. Between 2009 and 2021, 30 patients who underwent tissue expansion surgery were reviewed in a single hospital. The demographic data, lesion characteristics, surgical approaches, complication rate, and aesthetic outcomes were analyzed. Thirty patients (5 men and 25 women) with a mean age of 14.03 ± 7.25 years (range, 4-33years) were included. The mean follow-up is 35.92months, ranging from 9 to 75months. Tissue expansion-related complications include closed infection, 2/30 (6.67%); skin ischemia, 2/30 (6.67%); hematoma, 1/30 (3.33%); flap necrosis, 1/30 (3.33%). Large facial involuted infantile hemangiomas have variable patterns of presentation and necessitate tailored therapy. Tissue expansion is a reproducible approach to achieving aesthetic reconstruction. 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 .

Revisiting Scalp Tissue Expander In Indonesia: Restoration Of Cicatricial Alopecia

Background: Scalp alopecia from burn injuries significantly impacts physical appearance and psychological well-being, often leading to social phobia. Tissue expanders have been effective in reconstructive surgeries, offering advantages in restoring hair-bearing scalp areas with excellent color and texture match. However, comprehensive algorithms for their use, particularly in Indonesia, are lacking. Case Presentation: A 10-year-old girl with cicatricial alopecia on the right lateral, frontal, and vertex of the scalp from a burn injury sought reconstructive surgery due to teasing from peers. A 400 mL round silicone expander was implanted and gradually expanded over five weeks. Reconstruction surgery advanced the expanded flap towards the frontal area, improving her hairline. Despite minor necrosis at the flap’s distal margin, which healed by secondary intention, the outcome was favorable. Discussion: This case demonstrates the effectiveness of tissue expanders in scalp reconstruction. Benefits include improved cosmetic outcomes and decreased donor site morbidity, though complications such as infection and alopecia in the expanded tissue require careful management. The underutilization of tissue expanders in Indonesia may be due to lack of insurance coverage and limited local availability. Conclusion: Scalp tissue expansion is a beneficial technique for reconstructing scalp defects, especially in burn-induced alopecia. Wider adoption in regions with limited advanced modalities could significantly benefit patients.

C-terminally phosphorylated p27 activates self-renewal driver genes to program cancer stem cell expansion, mammary hyperplasia and cancer

In many cancers, a stem-like cell subpopulation mediates tumor initiation, dissemination and drug resistance. Here, we report that cancer stem cell (CSC) abundance is transcriptionally regulated by C-terminally phosphorylated p27 (p27pT157pT198). Mechanistically, this arises through p27 co-recruitment with STAT3/CBP to gene regulators of CSC self-renewal including MYC, the Notch ligand JAG1, and ANGPTL4. p27pTpT/STAT3 also recruits a SIN3A/HDAC1 complex to co-repress the Pyk2 inhibitor, PTPN12. Pyk2, in turn, activates STAT3, creating a feed-forward loop increasing stem-like properties in vitro and tumor-initiating stem cells in vivo. The p27-activated gene profile is over-represented in STAT3 activated human breast cancers. Furthermore, mammary transgenic expression of phosphomimetic, cyclin-CDK-binding defective p27 (p27CK-DD) increases mammary duct branching morphogenesis, yielding hyperplasia and microinvasive cancers that can metastasize to liver, further supporting a role for p27pTpT in CSC expansion. Thus, p27pTpT interacts with STAT3, driving transcriptional programs governing stem cell expansion or maintenance in normal and cancer tissues.

Evaluating Operative Times for Intraoperative Conversion of Axillary Node Biopsy to Axillary Lymph Node Dissection with Immediate Lymphatic Reconstruction.

Lymphedema can occur in patients undergoing axillary lymph node dissection (ALND) and radiation for breast cancer. Immediate lymphatic reconstruction (ILR) is performed to decrease the risk of lymphedema in patients after ALND. Some patients who ultimately require ALND are candidates for attempted sentinel lymph node biopsy (SLNB) or targeted axillary excision. In those scenarios, ALND can be performed (1) immediately if frozen sections are positive or (2) as a second operation following permanent pathology. The purpose of this study is to evaluate immediate ALND/ILR following positive intraoperative frozen sections to guide surgical decision-making and operative planning. A single-center retrospective review was performed (2019-2022) for breast cancer patients undergoing axillary node surgery with breast reconstruction. Patients were divided into two groups: immediate conversion to ALND/ILR (Group 1) and no immediate conversion to ALND (Group 2). Demographic data and operative time were recorded. There were 148 patients who underwent mastectomy, tissue expander (TE) reconstruction, and axillary node surgery. Group 1 included 30 patients who had mastectomy, sentinel node/targeted node biopsy, TE reconstruction, and intraoperative conversion to immediate ALND/ILR. Group 2 had 118 patients who underwent mastectomy with TE reconstruction and SLNB with no ALND or ILR. Operative time for bilateral surgery was 303.1 ± 63.2 minutes in Group 1 compared with 222.6 ± 52.2 minutes in Group 2 (p = 0.001). Operative time in Group 1 patients undergoing unilateral surgery was 252.3 ± 71.6 minutes compared with 171.3 ± 43.2 minutes in Group 2 (p = 0.001). Intraoperative frozen section of sentinel/targeted nodes extended operative time by approximately 80 minutes in patients undergoing mastectomy with breast reconstruction and conversion of SLNB to ALND/ILR. Intraoperative conversion to ALND adds unpredictability to the operation as well as additional potentially unaccounted operative time. However, staging ALND requires an additional operation.

Sleep deprivation induced fat accumulation in the visceral white adipose tissue by suppressing SIRT1/FOXO1/ATGL pathway activation.

Sleep is critical for maintaining overall health. Insufficient sleep duration and poor sleep quality are associated with various physical and mental health risks and chronic diseases. To date, plenty of epidemiological research has shown that sleep disorders are associated with the risk of obesity, which is usually featured by the expansion of adipose tissue. However, the underlying mechanism of increased fat accumulation upon sleep disorders remains unclear. Here we demonstrated that sleep deprivation (SD) caused triglycerides (TG) accumulation in the visceral white adipose tissue (vWAT), accompanied by a remarkable decrease in the expression of adipose triglyceride lipase (ATGL) and other two rate-limiting lipolytic enzymes. Due to the key role of ATGL in initiating and controlling lipolysis, we focused on investigating the signaling pathway leading to attenuated ATGL expression in vWAT upon SD in the following study. We observed that ATGL downregulation resulted from the suppression of ATGL transcription, which was mediated by the reduction of the transcriptional factor FOXO1 and its upstream regulator SIRT1 expression in vWAT after SD. Furthermore, impairment of SIRT1/FOXO1/ATGL pathway activation and lipolysis induced by SIRT1 inhibitor EX527 in the 3 T3-L1 adipocytes were efficiently rescued by the SIRT1 activator resveratrol. Most notably, resveratrol administration in SD mice revitalized the SIRT1/FOXO1/ATGL pathway activation and lipid mobilization in vWAT. These findings suggest that targeting the SIRT1/FOXO1/ATGL pathway may offer a promising strategy to mitigate fat accumulation in vWAT and reduce obesity risk associated with sleep disorders.

ExSeq: Expansion Sequencing for Single-Cell Spatial Transcriptomics

The innovation of spatial transcriptomics allows for the study of gene expression while preserving spatial information on the detected transcripts. Expansion Sequencing (ExSeq) is an advanced spatial transcriptomic method combining in situ sequencing with expansion microscopy, thus enablingthe sequencing of RNAs in a physically enlarged tissue. The experiment involves the steps of tissue expansion, RNA library preparation and multiplexed sequencing by rounds of fluorescent dye addition, imaging and fluorescent dye removal. ExSeq significantly enhances resolution capacity of RNA transcripts up to the nanoscale level, thus identifying subcellular location of RNAs. The method is applicable to exploring cellular RNA in an untargeted approach, as well as to specifically detecting certain RNA types in a targeted approach, thus making the method suitable for a variety of research questions. However, limitations to the method include referring to the readout length of transcripts obtainable during sequencing and the availability of the method. ExSeq has the potential to be used in multiple tissues to allow for new insights into cellular identity, heterogeneity, interactions and implications in diseases and could possibly be adapted to inquire other cellular molecules, such as DNA or proteins on a nanoscale level.

Deficiency of glucocorticoid receptor in bone marrow adipocytes has mild effects on bone and hematopoiesis but does not influence expansion of marrow adiposity with caloric restriction.

Unlike white adipose tissue depots, bone marrow adipose tissue (BMAT) expands during caloric restriction (CR). Although mechanisms for BMAT expansion remain unclear, prior research suggested an intermediary role for increased circulating glucocorticoids. In this study, we utilized a recently described mouse model (BMAd-Cre) to exclusively target bone marrow adipocytes (BMAds) for elimination of the glucocorticoid receptor (GR) (i.e. Nr3c1) whilst maintaining GR expression in other adipose depots. Mice lacking GR in BMAds (BMAd-Nr3c1 -/-) and control mice (BMAd-Nr3c1 +/+) were fed ad libitum or placed on a 30% CR diet for six weeks. On a normal chow diet, tibiae of female BMAd-Nr3c1-/- mice had slightly elevated proximal trabecular metaphyseal bone volume fraction and thickness. Both control and BMAd-Nr3c1-/- mice had increased circulating glucocorticoids and elevated numbers of BMAds in the proximal tibia following CR. However, no significant differences in trabecular and cortical bone were observed, and quantification with osmium tetroxide and μCT revealed no difference in BMAT accumulation between control or BMAd-Nr3c1 -/- mice. Differences in BMAd size were not observed between BMAd-Nr3c1-/- and control mice. Interestingly, BMAd-Nr3c1-/- mice had decreased circulating white blood cell counts 4h into the light cycle. In conclusion, our data suggest that eliminating GR from BMAd has minor effects on bone and hematopoiesis, and does not impair BMAT accumulation during CR.

One-Stage Deep Inferior Epigastric Perforator Flap Salvage of Infected Tissue Expanders

Background Tissue expander-based breast reconstruction is associated with high rates of infectious complications, often leading to tissue expander explants and delays in receipt of definitive breast reconstruction and adjuvant therapy. In this study, we describe a single-stage technique where deep inferior epigastric artery perforator (DIEP) flaps are used to salvage actively infected tissue expanders among patients originally planning for free flap reconstruction. Methods In this technique, patients with tissue expander infections without systemic illness are maintained on oral antibiotics until the day of their DIEP flap surgery, at which time tissue expander explant is performed in conjunction with aggressive attempt at total capsulectomy and immediate DIEP flap reconstruction. Patients are maintained on 1–2 weeks of oral antibiotics tailored to culture data. Patients undergoing this immediate salvage protocol were retrospectively reviewed, and complications and length of stay were assessed. Results In a retrospective series, a total of six consecutive patients with culture-proven tissue expander infections underwent tissue expander removal and DIEP flap reconstruction in a single stage and were maintained on 7–14 days of oral antibiotics postoperatively. Within this cohort, no surgical site infections, microvascular complications, partial flap losses, reoperations, or returns to the operating room were noted within a 90-day period. Conclusions Among a select cohort of patients, actively infected tissue expanders may be salvaged with free flap breast reconstruction in a single surgery with a low incidence of postoperative complications. Prospective studies are needed to evaluate the influence of this treatment strategy on costs, number of surgeries, and dissatisfaction after staged breast reconstruction complicated by tissue expander infections.

Periareolar Skin-Sparing Mastectomy and Immediate Implant-Based Reconstruction

Introduction Skin-sparing mastectomy (SSM) is often used when tumor location prohibits performing a nipple-sparing mastectomy (NSM). We examined a square excision of the nipple-areolar complex (NAC) and an X-shaped purse string closure after implant-based reconstruction. Methods A retrospective review was performed on patients undergoing periareolar SSM and immediate implant-based reconstruction from January 2015 through December 2022, specifically identifying those patients who had square NAC excision and skin closure. Results Twenty-nine patients met the inclusion criteria. They underwent 54 periareolar SSM and immediate implant-based reconstruction (bilateral 25, unilateral 4). Indications for surgery were cancer (30) and prophylactic (24; 2 patients had bilateral cancer). Reconstructive methods included tissue expander (TE) (36 [66.7%]) and direct-to-implant (DTI) (18 [33.3%]). The mean mastectomy weights and final implant sizes were similar between the 2 groups. Overall wound complications occurred in 13 (24.1%) of the breasts: mastectomy skin flap necrosis (MSFN; 10 [18.5%]) and infection (3 [5.6%]). Reconstructive failure occurred in 3 cases: TE, 1 (infection); DTI, 2 (MSFN/exposure). MSFN by reconstructive method: TE, 4 (11.1%); DTI, 6 (33.3%) (P = 0.05, comparing MSFN rates between TE and DTI methods). The mean initial TE fill volume was 247.1 cc; mean implant size in the DTI group was 417.8 cc (P &lt; 0.0001). Conclusions The square NAC excision and closure can minimize the surgical incision in implant reconstruction. Two-stage TE reconstruction permits lower initial fill volumes, which reduces the risk of MSFN after box to X closure of SSM and implant-based reconstruction. It is useful in small- to moderate-sized breasts with mild ptosis in patients who are not candidates for NSM.

Endoscopic Tissue Expander Implantation in Postburn Reconstruction: A Review of the Literature.

Tissue expansion generates new tissue that can be used in postburn reconstruction. Expanders are placed through small incisions, requiring difficult and sometimes blind dissection to prepare an adequate pocket. Recently, the use of endoscopy to assist in expander placement has been described, which may improve intraoperative visualization and allow for a smaller incision. In this review, we summarize the existing literature on endoscopic tissue expander (TE) placement in postburn reconstruction and highlight areas for future research. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were utilized to conduct this review. The following databases were queried for the initial search of relevant articles: PubMed, Embase, Scopus, Cochrane, and Web of Science. The data were assessed qualitatively due to the heterogeneity in reporting between the studies. Our literature query yielded 1023 studies. Sixteen manuscripts underwent full-text review, and 7 met inclusion criteria. All studies demonstrated that the endoscopic approach led to successful tissue expansion. Four articles performed a comparative analysis between the open and endoscopic approach, all of which found a significant reduction in complications like seroma, hematoma formation, and device exposure with endoscopic TE implantation. Two studies demonstrated that the use of endoscopy significantly reduced operative time and length of stay. Endoscopy is a safe and effective tool in tissue expansion for postburn reconstruction. Further prospective research should include evaluating the cost-benefit of this approach and long-term outcomes for patients who have undergone endoscopic-assisted TE placement.