Three-Dimensional Printing in Surgical Education: An Updated Systematic Review of the Literature.

INTRODUCTION: Three-dimensional printing (3DP) is being integrated into surgical practice at a significant pace, from preprocedural planning to procedure simulation. 3DP is especially useful in surgical education, where printed models are highly accurate and customizable. The aim of this study was to evaluate how 3DP is being integrated most recently into surgical residency training. METHODS: We performed a structured literature search of the OVID/MEDLINE, EMBASE, and PUBMED databases following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Articles published from 2016 to 2023 that met predefined inclusion and exclusion criteria were included. Data extracted included surgical subspecialty using 3DP, application of 3DP, and any reported satisfaction measures of trainees. A thorough analysis of pooled data was performed to evaluate satisfaction rates among studies. RESULTS: A total of 85 studies were included. The median number of participants was 18 (interquartile range 10-27). Fourteen surgical disciplines were represented, with ear, nose, and throat/otolaryngology having the highest recorded utilization of 3DP models among residents and medical students (22.0%), followed by neurosurgery (14.0%) and urology (12.0%). 3DP models were created most frequently to model soft tissue (35.3%), bone (24.7%), vessel (14.1%), mixed (16.4%), or whole organs (6.66%) (Fig.1). Feedback from trainees was overwhelmingly positive regarding the fidelity of the models and their support for integration into their training programs. Among trainees, the combined satisfaction rate with their use in the curriculum was 95% (95% confidence interval, 0.92-0.97), and the satisfaction rate with the model fidelity was 90% (95% confidence interval, 0.86-0.94). CONCLUSIONS: There is wide variation in the surgical specialties utilizing 3DP models in training. These models are effective in increasing trainee comfort with both common and rare scenarios and are associated with a high degree of resident support and satisfaction. Plastic surgery programs may benefit from the integration of this technology, potentially strengthening future surgical curricula. Objective evaluations of their pedagogic effects on residents are areas of future research.

Navigating Aesthetic Pursuits: A Google Trends Insight into Cosmetic Tourism.

BACKGROUND: The popularity of cosmetic tourism may increase unnecessary risks for patients as postoperative care is variable. However, little is known about the current trends and public perception of this growing phenomenon. This study compares interest in cosmetic tourism in popular medical tourism destinations relative to the US. METHODS: Google Trends was queried from October 2017 to September 2023, examining trends over the full period and dissecting changes between 2017-2020 and 2020-2023. Search volume data were retrieved for the top international countries and the US for each of the top five cosmetic procedures, according to the ISAPS 2022 Global Survey. A p value < 0.05 was used for statistical significance. RESULTS: Searches for liposuction, blepharoplasty, breast augmentation, mastopexy, and abdominoplasty were compared between the US, Mexico, Turkey, Thailand, and Colombia. Google Trends data mirrored the prevalence of the two most common procedures, liposuction, and breast augmentation. Differences in interest regarding liposuction were greatest in Mexico, Thailand, and Turkey compared to the US (p < 0.05). Medical tourism for blepharoplasty had the highest search interest scores for Turkey and Thailand from 2017 to 2023 (p < 0.05). Significant differences were also consistent across all time intervals for breast augmentation, mastopexy, and abdominoplasty, with higher interest in Mexico and Turkey (p < 0.05). CONCLUSIONS: Google Trends analysis serves as an insightful tool for understanding cosmetic tourism. Changing trends bring the potential to assess worldwide versus country-specific procedure interest. These observed trends may foreshadow future international aesthetic procedure trends. 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.

Association of Metabolic Derangement and Postoperative Outcomes in Hernia Repair With Component Separation: A Propensity Score-matched Nationwide Analysis.

INTRODUCTION: Metabolic syndrome (MetS) is characterized by cardiometabolic abnormalities such as hypertension, obesity, diabetes, or dyslipidemia. This study aims to evaluate the association of MetS on the postoperative outcomes of ventral, umbilical, and epigastric hernia repair using component separation. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients who underwent ventral, umbilical, and epigastric hernia repair with component separation between 2015 and 2021. MetS status was defined as patients receiving medical treatment for diabetes mellitus and hypertension, with a body mass index greater than 30 kg/m2. Propensity matching was performed to generate two balanced cohorts with and without MetS. T-tests and Fisher's Exact tests assessed group differences. Logistic regression models evaluated complications between the groups. RESULTS: After propensity score matching, 3930 patients were included in the analysis, with 1965 in each group (MetS versus non-MetS). Significant differences were observed in the severity and clinical presentation of hernias between the groups. The MetS cohort had higher rates of incarcerated hernia (39.1% versus 33.2%; P < 0.001), and recurrent ventral hernia (42.7% versus 36.5%; P < 0.001) compared to the non-MetS cohort. The MetS group demonstrated significantly increased rates of renal insufficiency (P = 0.026), unplanned intubation (P = 0.003), cardiac arrest (P = 0.005), and reoperation rates (P = 0.002) than the non-MetS cohort. Logistic regression models demonstrated higher likelihood of postoperative complications in the MetS group, including mild systemic complications (OR 1.25; 95%CI 1.030-1.518; P = 0.024), severe systemic complications (OR 1.63; 95%CI 1.248-2.120; P < 0.001), and reoperation (OR 1.47; 95%CI 1.158-1.866; P = 0.002). There were no significant differences in the rates of 30-d wound complications between groups. CONCLUSIONS: The presence of metabolic derangement appears to be associated with adverse postoperative medical outcomes and increased reoperation rates after hernia repair with component separation. These findings highlight the importance of optimizing preoperative comorbidities as surgeons counsel patients with MetS.

An Institutional Analysis of Early Postoperative Free Tissue Transfer Takeback Procedures.

BACKGROUND: Postoperative free tissue transfer reexploration procedures are relatively infrequent but associated with increased overall failure rates. This study examines the differences between flaps requiring takeback versus no takeback, as well as trends in reexploration techniques that may increase the odds of successful salvage. METHODS: A retrospective review was conducted on all free tissue transfers performed at our institution from 2011 to 2022. Patients who underwent flap reexploration within 30 days of the original procedure were compared with a randomly selected control group who underwent free flap procedures without reexploration (1:2 cases to controls). Univariate and multivariate logistic regression analyses were performed. RESULTS: From 1,213 free tissue transfers performed in the study period, 187 patients were included in the analysis. Of the total flaps performed, 62 (0.05%) required takeback, and 125 were randomly selected as a control group. Free flap indication, flap type, reconstruction location, and number of venous anastomoses differed significantly between the two groups. Among the reexplored flaps, 8 (4.3% of the total) had a subsequent failure while 54 (87.10%) were salvaged, with significant differences in cause of initial flap failure, affected vessel type, and salvage technique. CONCLUSION: Free tissue transfers least prone to reexploration involved breast reconstruction in patients without predisposition to hypercoagulability or reconstruction history. When takeback operations were required, salvage was more likely in those without microvascular compromise or with an isolated venous injury who required a single exploratory operation.

Effect of pedicle type on breast reduction: Clinical and patient-reported outcomes.

PURPOSE: The choice of pedicle in reduction mammaplasty is highly variable with prior studies demonstrating high patient satisfaction in most cases. This study aimed to examine the impact of pedicle type on clinical and patient-reported outcomes in patients undergoing reduction mammaplasty. METHODS: A total of 588 patients underwent bilateral reduction mammaplasty with Wise pattern or modified Robertson incision by 13 surgeons at a single institution. Clinical outcomes were compared according to the pedicle type in all patients and BREAST-Q responders (32% response rate). Survey respondents were sub-grouped by resection volume, and the BREAST-Q satisfaction scores were compared. RESULTS: Among all included reduction mammoplasties, 439 (75%) were performed using inferior pedicles, and 149 (25%) using superior or superomedial pedicles. Responders and non-responders were similar in preoperative characteristics including age, body measurements, and comorbidities. Although a higher incidence of infection occurred among the responders, clinical outcomes were comparable across all pedicle types. A total of 187 patients completed the BREAST-Q. Compared to the superior pedicle group, respondents in the inferior pedicle group reported higher nipple satisfaction, even when adjusted for resection weight over 500 g. In contrast, the superior pedicle group had better sexual well-being scores, which persisted in resection weight less than 500 g (all p values <0.05). CONCLUSION: Inferior pedicles were associated with greater nipple satisfaction and superior pedicles were associated with greater sexual satisfaction. Our findings suggest that those with resections less than 500 g were more satisfied with superior pedicles whereas those with greater resections were more satisfied with inferior pedicles.

Improving Readability and Automating Content Analysis of Plastic Surgery Webpages With ChatGPT.

INTRODUCTION: The quality and readability of online health information are sometimes suboptimal, reducing their usefulness to patients. Manual evaluation of online medical information is time-consuming and error-prone. This study automates content analysis and readability improvement of private-practice plastic surgery webpages using ChatGPT. METHODS: The first 70 Google search results of "breast implant size factors" and "breast implant size decision" were screened. ChatGPT 3.5 and 4.0 were utilized with two prompts (1: general, 2: specific) to automate content analysis and rewrite webpages with improved readability. ChatGPT content analysis outputs were classified as hallucination (false positive), accurate (true positive or true negative), or omission (false negative) using human-rated scores as a benchmark. Six readability metric scores of original and revised webpage texts were compared. RESULTS: Seventy-five webpages were included. Significant improvements were achieved from baseline in six readability metric scores using a specific-instruction prompt with ChatGPT 3.5 (all P ≤ 0.05). No further improvements in readability scores were achieved with ChatGPT 4.0. Rates of hallucination, accuracy, and omission in ChatGPT content scoring varied widely between decision-making factors. Compared to ChatGPT 3.5, average accuracy rates increased while omission rates decreased with ChatGPT 4.0 content analysis output. CONCLUSIONS: ChatGPT offers an innovative approach to enhancing the quality of online medical information and expanding the capabilities of plastic surgery research and practice. Automation of content analysis is limited by ChatGPT 3.5's high omission rates and ChatGPT 4.0's high hallucination rates. Our results also underscore the importance of iterative prompt design to optimize ChatGPT performance in research tasks.

Barriers of Three-Dimensional Printing in Craniofacial Plastic Surgery Practice: A Pilot Study and Literature Review.

OBJECTIVE: Three-dimensional printing (3Dp) and modeling have demonstrated increasing utility within plastic and reconstructive surgery (PRS). This study aims to understand the prevalence of how this technology is utilized in craniofacial surgery, as well as identify barriers that may limit its integration into practice. METHODS: A survey was developed to assess participant demographics, characteristics of 3Dp use, and barriers to utilizing three-dimensional technologies in practice. The survey was distributed to practicing craniofacial surgeons. A secondary literature review was conducted to identify solutions for barriers and potential areas for innovation. RESULTS: Fifteen complete responses (9.7% response rate) were analyzed. The majority (73%) reported using three-dimensional modeling and printing in their practice, primarily for surgical planning. The majority (64%) relied exclusively on outside facilities to print the models, selecting resources required to train self and staff (55%), followed by the cost of staff to run the printer (36%), as the most common barriers affecting 3Dp use in their practice. Of those that did not use 3Dp, the most common barrier was lack of exposure (75%). The literature review revealed cost-lowering techniques with materials, comparability of desktop commercial printers to industrial printers, and incorporation of open-source software. CONCLUSIONS: The main barrier to integrating 3Dp in craniofacial plastic and reconstructive surgery practice is the perceived cost associated with utilizing the technology. Ongoing literature highlights the cost-utility of in-house 3Dp technologies and practical cost-saving methods. The authors' results underscore the need for broad exposure for currently practicing attendings and trainees in 3Dp practices and other evolving technologies.

The value of microvascular breast reconstruction: Cost equivalence of TRAM and DIEP flaps implications in the era of CMS reforms.

BACKGROUND: Recent CMS billing changes have raised concerns about insurance coverage for deep inferior epigastric perforator (DIEP) flap breast reconstruction. This study compared the costs and utilization of transverse rectus abdominis myocutaneous (TRAM), DIEP, and latissimus dorsi (LD) flaps in breast reconstruction. METHOD: The study utilized the National Inpatient Sample database to identify female patients who underwent DIEP, TRAM, and LD flap procedures from 2016 to 2019. Key data such as patient demographics, length of stay, complications, and costs (adjusted to 2021 USD) were analyzed, focusing on differences across the flap types. RESULTS: A total of 17,770 weighted patient encounters were identified, with the median age being 51. The majority underwent DIEP flaps (73.5%), followed by TRAM (14.2%) and LD (12.1%) flaps. The findings revealed that DIEP and TRAM flaps had a similar length of stay (LOS), while LD flaps typically had a shorter LOS. The total hospital charges to costs using cost-to-charge ratio were also comparable between DIEP and TRAM flaps, whereas LD flaps were significantly less expensive. Factors such as income quartile, primary payer of hospitalization, and geographic region significantly influenced flap choice. CONCLUSION: The study's results appear to contradict the prevailing notion that TRAM flaps are more cost-effective than DIEP flaps. The total hospital charges to costs using cost-to-charge ratio and hospital stays associated with TRAM and DIEP flaps were found to be similar. These findings suggest that changes in the insurance landscape, which may limit the use of DIEP flaps, could undermine patient autonomy while not necessarily reducing healthcare costs. Such policy shifts could favor less costly options like the LD flap, potentially altering the landscape of microvascular breast reconstruction.

Laser Therapy in Hypertrophic and Keloid Scars: A Systematic Review and Network Meta-analysis.

BACKGROUND: Laser therapy has emerged as a promising treatment modality for improving the appearance and symptoms associated with hypertrophic and keloid scars. In this network meta-analysis, we aimed to evaluate the efficacy of different laser types in treating hypertrophic and keloid scars. METHODS: A comprehensive search of four databases was conducted to identify relevant studies published up until July 2023. Data were extracted from eligible studies and pooled as mean difference (MD) for continuous outcomes and risk ratio (RR) for dichotomous data in a network meta-analysis (NMA) model, using R software. RESULTS: A total of 18 studies, comprising 550 patients, were included in the analysis. Pooling our data showed that fractional carbon dioxide (FCO2) plus 5-fluorouracil (5-FU) was superior to control in terms of Vancouver Scar Scale (VSS), pliability score, and thickness; [MD = - 5.97; 95% CI (- 7.30; - 4.65)], [MD = - 2.68; 95% CI (- 4.03; - 1.33)], [MD = - 2.22; 95% CI (- 3.13; - 1.31)], respectively. However, insignificant difference was observed among FCO2 plus 5-FU compared to control group in terms of erythema, vascularity, redness and perfusion, and pigmentation [MD = - 0.71; 95% CI (- 2.72; 1.30)], [MD = - 0.44; 95% CI (- 1.26; 0.38)], respectively. CONCLUSION: Our NMA found that the FCO2 plus 5-FU was the most effective intervention in decreasing the VSS and thickness, while FCO2 plus CO2 was the most effective intervention in decreasing the pliability score. Further research is needed to determine the optimal laser parameters and long-term efficacy of laser therapy in hypertrophic and keloid scars. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Redefining Surgical Materials: Applications of Silk Fibroin in Osteofixation and Fracture Repair.

Silk and silk derivatives have emerged as a possible alternative in surgical device development, offering mechanical strength, biocompatibility, and environmental sustainability. Through a systematic review following PRISMA guidelines, this study evaluated silk fibroin's application across pre-clinical and clinical settings, focusing on its role as screws and plates for osteofixation. A comprehensive search yielded 245 studies, with 33 subjected to full-text review and 15 ultimately included for qualitative analysis. The findings underscore silk fibroin's superior properties, including its tunable degradation rates and ability to be functionalized with therapeutic agents. In vivo and in vitro studies demonstrated its efficacy in enhancing bone healing, offering improved outcomes in osteofixation, particularly for craniofacial defects. Silk fibroin's remarkable attributes in biodegradation and drug release capabilities underscore its potential to enhance patient care. Ultimately, silk fibroin's integration into surgical practices promises a revolution in patient outcomes and environmental sustainability. Its versatility, coupled with the continuous progress in fabrication techniques, signals a promising horizon for its widespread acceptance in the medical field, potentially establishing a new benchmark in surgical treatment. Further research is expected to solidify the transition of silk products from basic science to patient care, paving the way for widespread use in various surgical applications.

Racial and ethnic representation in united states plastic surgery clinical trials: A systematic review and meta-analysis.

In 1993, the National Institutes of Health Revitalization Act mandated increasing minority and women enrollment in clinical trials (CTs). This study aimed to investigate trends in race and ethnicity enrollment and reporting in US plastic and reconstructive surgery (PRS) CT. METHODS: A comprehensive systematic review was performed. All CTs in PRS from 2012 to 2022 were included. To assess racial and ethnic representation within CTs, a random-effects meta-analysis of proportion was conducted to pool the prevalence of the binomial data. RESULTS: A total of 3609 studies were initially identified in the search strategy, with 154 later classified as CTs in PRS. Only 36 met the eligibility criteria for reporting race and ethnicity and were included in the analysis. A total of 7281 participants were included: 446 (6.1%) males and 6835 (93.9%) females. From CTs that correctly reported race, the pooled prevalence of races were as follows: Whites 78% (95% confidence interval [CI] 73-82%), Black or African Americans 8% (95% CI 5-11%), Asians 1% (95% CI <1-2%), American Indians <1% (95% CI <1-<1%), and Pacific Islanders <1% (95% CI <1-<1%). From the studies that reported ethnicity correctly, the pooled prevalence of Hispanics was 7% (95% CI 5-9%), and Non-Hispanics was 12% (<1-38%). CONCLUSIONS: Disparities in minority representation were present among PRS CTs. This suggests clear limitations in generalizing PRS CT results to the population. Efforts to decrease the gap in minority enrollment and accurately report race and ethnicity are needed in all fields, including plastic surgery.

From Case Reports to Molecular Insight: Examining the Outcomes and Underlying Mechanisms of Squamous Cell Carcinoma in Breast Implant Patients-A Systematic Review.

There is extensive coverage in the existing literature on implant-associated lymphomas like anaplastic large-cell lymphoma, but breast implant-associated squamous cell carcinoma (BIA-SCC) has received limited scholarly attention since its first case in 1992. Thus, this study aims to conduct a qualitative synthesis focused on the underexplored association between breast implants and BIA-SCC. A systematic review was conducted utilizing the PubMed, Web of Science, and Cochrane databases to identify all currently reported cases of BIA-SCC. Additionally, a literature review was performed to identify potential biochemical mechanisms that could lead to BIA-SCC. Studies were vetted for quality using the NIH quality assessment tool. From an initial pool of 246 papers, 11 met the quality criteria for inclusion, examining a total of 14 patients aged between 40 and 81 years. BIA-SCC was found in a diverse range of implants, including those with smooth and textured surfaces, as well as those filled with saline and silicone. The condition notably manifested a proclivity for aggressive clinical progression, as evidenced by a mortality rate approximating 21.4% within a post-diagnostic interval of six months. Our literature review reveals that chronic inflammation, driven by various external factors such as pathogens and implants, can initiate carcinogenesis through epigenetic modifications and immune system alterations. This includes effects from exosomes and macrophage polarization, showcasing potential pathways for the pathogenesis of BIA-SCC. The study highlights the pressing need for further investigation into BIA-SCC, a subject hitherto inadequately addressed in the academic sphere. This necessitates the urgency for early screening and intervention to improve postoperative outcomes. While the review is confined by its reliance on case reports and series, it serves as a valuable reference for future research endeavors.

Pedicled Flaps for High-Risk Open Vascular Procedures of the Lower Extremity: An Analysis of The National Surgical Quality Improvement Project Database.

BACKGROUND: Use of pedicled flaps in vascular procedures is associated with decreased infection and wound breakdown. We evaluated the risk profile and postoperative complications associated with lower extremity open vascular procedures with and without pedicled flaps. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database (2010-2020) was queried for Current Procedural Terminology codes representing lower extremity open vascular procedures, including trunk and lower extremity pedicled flaps. Flap patients were compared with a randomized control group without flaps (1:3 cases to controls). Univariate and multivariate analyses were performed. RESULTS: We identified 132,934 adults who underwent lower extremity open vascular procedures. Concurrent pedicled flaps were rare (0.7%), and patients undergoing bypass procedures were more likely to receive a flap than nonbypass patients (69 vs. 64%, p < 0.0001). Flap patients had greater comorbidities. On univariate analysis, flap patients were more likely to experience wound (p = 0.0026), mild systemic (p < 0.0001), severe systemic (p = 0.0452), and all-cause complications (p < 0.0001). After adjusting for factors clinically suspected to be associated with increased risk (gender, body mass index, procedure type, American Society of Anesthesiologists classification, functional status, diabetes, smoking, and albumin < 3.5 mg/dL), wound (p = 0.096) and severe systemic complications (p = 0.0719) were no longer significantly associated with flap patients. CONCLUSION: Lower extremity vascular procedures are associated with a high risk of complications. Use of pedicled flaps remains uncommon and more often performed in patients with greater comorbid disease. However, after risk adjustment, use of a pedicled flap in high-risk patients may be associated with lower than expected wound and severe systemic complications.

Incidental Bystander or Essential Culprit: A Systematic Review of Bacterial Significance in the Pathogenesis of Breast Implant-Associated Anaplastic Large Cell Lymphoma.

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a distinct subtype of T-cell non-Hodgkin lymphoma that arises in the context of prolonged exposure to textured breast implants. The intent of this manuscript is to explore whether the bacterial presence in biofilms on these implants is a mere incidental finding or plays a pivotal role in the pathogenesis of BIA-ALCL. Our goal is to delineate the extent of bacterial involvement, offering insights into potential underlying mechanisms, and establishing future research priorities aimed at resolving the remaining uncertainties surrounding this complex association. A comprehensive systematic review of several databases was performed. The search strategy was designed and conducted by an experienced librarian using controlled vocabulary with keywords. The electronic search identified 442 publications. After evaluation, six studies from 2015 to 2021 were included, encompassing 201 female patients aged 23 to 75. The diagnosis span post-implantation ranged from 53 to 135.6 months. Studies consistently found bacteria near breast implants in both BIA-ALCL cases and controls, with varied microbial findings. Both BIA-ALCL cases and controls exhibited the presence of specific bacteria, including Pseudomonas aeruginosa, Klebsiella oxytoca, Staphylococcus aureus, and Ralstonia spp., without any statistically significant differences between groups. The use of antiseptic and antimicrobial agents during implant insertion did not demonstrate any impact on reducing or altering the risk of developing BIA-ALCL. Our systematic review reveals that the current evidence is inadequate to link bacterial etiology as a central factor in the development of BIA-ALCL. The limitations in the existing data prevent a complete dismissal of the role of biofilms in its pathogenesis. The observed gap in knowledge underscores the need for more focused and comprehensive research, which should be structured in a multi-faceted approach. Initially, this involves the utilization of sophisticated genomic and proteomic methods. Following this, it is crucial to delve into the study of immunological reactions specifically induced by biofilms. Finally, this research should incorporate extended observational studies, meticulously tracking the evolution of biofilm development and its correlation with the emergence of BIA-ALCL. In light of the inconclusive nature of current findings, further investigation is not only justified but urgently needed to clarify these unresolved issues.

Ecological constraints on highly evolvable olfactory receptor genes and morphology in neotropical bats.

Although evolvability of genes and traits may promote specialization during species diversification, how ecology subsequently restricts such variation remains unclear. Chemosensation requires animals to decipher a complex chemical background to locate fitness-related resources, and thus the underlying genomic architecture and morphology must cope with constant exposure to a changing odorant landscape; detecting adaptation amidst extensive chemosensory diversity is an open challenge. In phyllostomid bats, an ecologically diverse clade that evolved plant visiting from a presumed insectivorous ancestor, the evolution of novel food detection mechanisms is suggested to be a key innovation, as plant-visiting species rely strongly on olfaction, supplementarily using echolocation. If this is true, exceptional variation in underlying olfactory genes and phenotypes may have preceded dietary diversification. We compared olfactory receptor (OR) genes sequenced from olfactory epithelium transcriptomes and olfactory epithelium surface area of bats with differing diets. Surprisingly, although OR evolution rates were quite variable and generally high, they are largely independent of diet. Olfactory epithelial surface area, however, is relatively larger in plant-visiting bats and there is an inverse relationship between OR evolution rates and surface area. Relatively larger surface areas suggest greater reliance on olfactory detection and stronger constraint on maintaining an already diverse OR repertoire. Instead of the typical case in which specialization and elaboration are coupled with rapid diversification of associated genes, here the relevant genes are already evolving so quickly that increased reliance on smell has led to stabilizing selection, presumably to maintain the ability to consistently discriminate among specific odorants-a potential ecological constraint on sensory evolution.

The importance of clear margins in myxofibrosarcoma: Improving local control by means of staged resection and reconstruction.

INTRODUCTION: Myxofibrosarcomas are associated with a locally infiltrative growth pattern, making a clear-margin resection margin challenging. This leads to high local recurrence rates. While immediate wound closure and adjuvant radiotherapy has been proposed to mitigate incomplete excisions, we present our experience treating myxofibrosarcomas with staged excisions until clear margins are obtained, prior to reconstruction. METHODS: All patients with myxofibrosarcomas treated with a curative intent at our centre between 2009 and 2019 were identified. Patient demographics, tumour characteristics, number of resections, method of reconstruction, adjuvant therapy, complications, local recurrence rates, length of hospital stay and overall survival were assessed. RESULTS: 97 consecutive eligible patients were identified. Forty-six (47%) had positive margins reported following a first resection. The median number of resections required to obtain clear margins was two and the median time from first excision to definitive wound closure was 15 days. Local recurrence rate for the whole cohort was 14%. Patients who had staged resection until clear margins were obtained had a significantly lower rate of local recurrence compared to those who had positive margins at time of reconstruction (p-value = 0.001). The estimated 5-year disease-specific survival for the whole cohort was 93%. DISCUSSION: Obtaining clear margins in myxofibrosarcoma via staged resections was associated with lower local recurrence rates for patients who had an initial resection with positive margins. The outcomes of performing staged resections are equivalent to patients for whom a clear margin were obtained in the first instance.

Sarcomas in the groin and inguinal canal: A 16-year single-centre experience.

INTRODUCTION: Soft tissue sarcomas arising in the groin and inguinal canal can be difficult to diagnose and manage. This is in part explained by the complex anatomy of the region. Early referral to specialist centres has been advocated, as inadvertent excision of these tumours can jeopardise definitive treatment. We present our 16-year experience at a regional sarcoma service. MATERIALS AND METHODS: A retrospective review of patients treated for a sarcoma in the groin and inguinal canal within the North of England Bone and Soft Tissue Tumour Service was performed. Demographic information, along with therapeutic approach and outcomes, was recorded and analysed. RESULTS: A total of 67 patients were identified, out of which 18 presented with new lesions, 32 presented after having a previous inadvertent sarcoma excision, 10 had a planned resection and 7 presented with recurrent disease. Liposarcomas were the most common histological subtype (55%), and the spermatic cord the most common origin (45%). Fifty-seven patients had surgery for this condition, with seven incomplete excision. Regional flaps were used in 60% of the cases, to allow an adequate oncological resection and soft tissue cover. Patients who had undergone a previous inadvertent sarcoma excision did not have worse rates of local recurrence, metastases and disease-specific mortality. Kaplan-Meier disease-specific survival at 5 years was 82%. DISCUSSION: Inadvertent and inadequate groin sarcoma excision outside of specialist centres remains a problem despite clear guidance. Despite this, an aggressive oncological approach to inadequately managed tumours shows similar outcomes as tumour managed exclusively by our specialist centre.

Endocrine regulation of MFS2 by branchless controls phosphate excretion and stone formation in Drosophila renal tubules.

How inorganic phosphate (Pi) homeostasis is regulated in Drosophila is currently unknown. We here identify MFS2 as a key Pi transporter in fly renal (Malpighian) tubules. Consistent with its role in Pi excretion, we found that dietary Pi induces MFS2 expression. This results in the formation of Malpighian calcium-Pi stones, while RNAi-mediated knockdown of MFS2 increases blood (hemolymph) Pi and decreases formation of Malpighian tubule stones in flies cultured on high Pi medium. Conversely, microinjection of adults with the phosphaturic human hormone fibroblast growth factor 23 (FGF23) induces tubule expression of MFS2 and decreases blood Pi. This action of FGF23 is blocked by genetic ablation of MFS2. Furthermore, genetic overexpression of the fly FGF branchless (bnl) in the tubules induces expression of MFS2 and increases Malpighian tubule stones suggesting that bnl is the endogenous phosphaturic hormone in adult flies. Finally, genetic ablation of MFS2 increased fly life span, suggesting that Malpighian tubule stones are a key element whereby high Pi diet reduces fly longevity previously reported by us. In conclusion, MFS2 mediates excretion of Pi in Drosophila, which is as in higher species under the hormonal control of FGF-signaling.