Impact of fellow compared to resident assistance on outcomes of minimally invasive surgery.

INTRODUCTION: As fellowship training after general surgery residency has become increasingly common, the impact on resident education must be considered. Patient safety and procedure outcomes are often used as justification by attendings who favor fellows over residents in certain minimally invasive surgery (MIS) operations. The aim of the present study was to compare the impact of trainee level on the outcomes of selected MIS operations to determine if giving preference to fellows on grounds of outcomes is warranted. METHODS: Patients who underwent elective laparoscopic hiatal hernia repair (LHHR), laparoscopic sleeve gastrectomy (LSG), laparoscopic Roux-en-Y gastric bypass (LRYGB), laparoscopic splenectomy (LS), laparoscopic cholecystectomy (LC), or laparoscopic ventral hernia repair (LVHR) with assistance of a general surgery chief resident or fellow were identified from the American College of Surgeon's National Surgical Quality Improvement Program database (2007-2012). Patients were matched 1:1 based on propensity score for the odds of undergoing operations assisted by a fellow. RESULTS: 5145 patients underwent LHHR, 1396 LSG, 9656 LRYGB, 863 LS, 13,434 LC, and 3069 LVHR. Fellows assisted in 41.7% of LHHR, 49.2% of LSG, 56.4% of LRYGB, 25.7% of LS, 17.1% of LC, and 27.0% of LVHR cases. After matching, overall and severe complication rates were comparable between cases performed with assistance of a fellow or chief resident. Median operative time was longer for LSG, LRYGB, and LC when a fellow assisted. CONCLUSIONS: Surgical outcomes were similar between fellow and chief resident assistance in MIS operations, arguing that increased resident participation in basic and complex laparoscopic operations is appropriate without compromising patient safety.

Development and validation of machine learning models to predict gastrointestinal leak and venous thromboembolism after weight loss surgery: an analysis of the MBSAQIP database.

BACKGROUND: Postoperative gastrointestinal leak and venous thromboembolism (VTE) are devastating complications of bariatric surgery. The performance of currently available predictive models for these complications remains wanting, while machine learning has shown promise to improve on traditional modeling approaches. The purpose of this study was to compare the ability of two machine learning strategies, artificial neural networks (ANNs), and gradient boosting machines (XGBs) to conventional models using logistic regression (LR) in predicting leak and VTE after bariatric surgery. METHODS: ANN, XGB, and LR prediction models for leak and VTE among adults undergoing initial elective weight loss surgery were trained and validated using preoperative data from 2015 to 2017 from Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database. Data were randomly split into training, validation, and testing populations. Model performance was measured by the area under the receiver operating characteristic curve (AUC) on the testing data for each model. RESULTS: The study cohort contained 436,807 patients. The incidences of leak and VTE were 0.70% and 0.46%. ANN (AUC 0.75, 95% CI 0.73-0.78) was the best-performing model for predicting leak, followed by XGB (AUC 0.70, 95% CI 0.68-0.72) and then LR (AUC 0.63, 95% CI 0.61-0.65, p < 0.001 for all comparisons). In detecting VTE, ANN, and XGB, LR achieved similar AUCs of 0.65 (95% CI 0.63-0.68), 0.67 (95% CI 0.64-0.70), and 0.64 (95% CI 0.61-0.66), respectively; the performance difference between XGB and LR was statistically significant (p = 0.001). CONCLUSIONS: ANN and XGB outperformed traditional LR in predicting leak. These results suggest that ML has the potential to improve risk stratification for bariatric surgery, especially as techniques to extract more granular data from medical records improve. Further studies investigating the merits of machine learning to improve patient selection and risk management in bariatric surgery are warranted.

Oxidative modifications of mitochondrial complex II are associated with insulin resistance of visceral fat in obesity.

Obesity, particularly visceral adiposity, has been linked to mitochondrial dysfunction and increased oxidative stress, which have been suggested as mechanisms of insulin resistance. The mechanism(s) behind this remains incompletely understood. In this study, we hypothesized that mitochondrial complex II dysfunction plays a role in impaired insulin sensitivity in visceral adipose tissue of subjects with obesity. We obtained subcutaneous and visceral adipose tissue biopsies from 43 subjects with obesity (body mass index ≥ 30 kg/m2) during planned bariatric surgery. Compared with subcutaneous adipose tissue, visceral adipose tissue exhibited decreased complex II activity, which was restored with the reducing agent dithiothreitol (5 mM) ( P < 0.01). A biotin switch assay identified that cysteine oxidative posttranslational modifications (OPTM) in complex II subunit A (succinate dehydrogenase A) were increased in visceral vs. subcutaneous fat ( P < 0.05). Insulin treatment (100 nM) stimulated complex II activity in subcutaneous fat ( P < 0.05). In contrast, insulin treatment of visceral fat led to a decrease in complex II activity ( P < 0.01), which was restored with addition of the mitochondria-specific oxidant scavenger mito-TEMPO (10 µM). In a cohort of 10 subjects with severe obesity, surgical weight loss decreased OPTM and restored complex II activity, exclusively in the visceral depot. Mitochondrial complex II may be an unrecognized and novel mediator of insulin resistance associated with visceral adiposity. The activity of complex II is improved by weight loss, which may contribute to metabolic improvements associated with bariatric surgery.

WNT5A regulates adipose tissue angiogenesis via antiangiogenic VEGF-A165b in obese humans.

Experimental studies have suggested that Wingless-related integration site 5A (WNT5A) is a proinflammatory secreted protein that is associated with metabolic dysfunction in obesity. Impaired angiogenesis in fat depots has been implicated in the development of adipose tissue capillary rarefaction, hypoxia, inflammation, and metabolic dysfunction. We have recently demonstrated that impaired adipose tissue angiogenesis is associated with overexpression of antiangiogenic factor VEGF-A165b in human fat and the systemic circulation. In the present study, we postulated that upregulation of WNT5A is associated with angiogenic dysfunction and examined its role in regulating VEGF-A165b expression in human obesity. We biopsied subcutaneous and visceral adipose tissue from 38 obese individuals (body mass index: 44 ± 7 kg/m2, age: 37 ± 11 yr) during planned bariatric surgery and characterized depot-specific protein expression of VEGF-A165b and WNT5A using Western blot analysis. In both subcutaneous and visceral fat, VEGF-A165b expression correlated strongly with WNT5A protein (r = 0.9, P < 0.001). In subcutaneous adipose tissue where angiogenic capacity is greater than in the visceral depot, exogenous human recombinant WNT5A increased VEGF-A165b expression in both whole adipose tissue and isolated vascular endothelial cell fractions (P < 0.01 and P < 0.05, respectively). This was associated with markedly blunted angiogenic capillary sprout formation in human fat pad explants. Moreover, recombinant WNT5A increased secretion of soluble fms-like tyrosine kinase-1, a negative regulator of angiogenesis, in the sprout media (P < 0.01). Both VEGF-A165b-neutralizing antibody and secreted frizzled-related protein 5, which acts as a decoy receptor for WNT5A, significantly improved capillary sprout formation and reduced soluble fms-like tyrosine kinase-1 production (P < 0.05). We demonstrated a significant regulatory nexus between WNT5A and antiangiogenic VEGF-A165b in the adipose tissue of obese subjects that was linked to angiogenic dysfunction. Elevated WNT5A expression in obesity may function as a negative regulator of angiogenesis.NEW & NOTEWORTHY Wingless-related integration site 5a (WNT5A) negatively regulates adipose tissue angiogenesis via VEGF-A165b in human obesity.

Relationships between study habits, burnout, and general surgery resident performance on the American Board of Surgery In-Training Examination.

BACKGROUND: The American Board of Surgery In-Training Examination (ABSITE) is used by programs to evaluate the knowledge and readiness of trainees to sit for the general surgery qualifying examination. It is often used as a tool for resident promotion and may be used by fellowship programs to evaluate candidates. Burnout has been associated with job performance and satisfaction; however, its presence and effects on surgical trainees' performance are not well studied. We sought to understand factors including burnout and study habits that may contribute to performance on the ABSITE examination. METHODS: Anonymous electronic surveys were distributed to all residents at 10 surgical residency programs (n = 326). Questions included demographics as well as study habits, career interests, residency characteristics, and burnout scores using the Oldenburg Burnout Inventory, which assesses burnout because of both exhaustion and disengagement. These surveys were then linked to the individual's 2016 ABSITE and United States Medical Licensing Examination (USMLE) step 1 and 2 scores provided by the programs to determine factors associated with successful ABSITE performance. RESULTS: In total, 48% (n = 157) of the residents completed the survey. Of those completing the survey, 48 (31%) scored in the highest ABSITE quartile (≥75th percentile) and 109 (69%) scored less than the 75th percentile. In univariate analyses, those in the highest ABSITE quartile had significantly higher USMLE step 1 and step 2 scores (P < 0.001), significantly lower burnout scores (disengagement, P < 0.01; exhaustion, P < 0.04), and held opinions that the ABSITE was important for improving their surgical knowledge (P < 0.01). They also read more frequently to prepare for the ABSITE (P < 0.001), had more disciplined study habits (P < 0.001), were more likely to study at the hospital or other public settings (e.g., library, coffee shop compared with at home; P < 0.04), and used active rather than passive study strategies (P < 0.04). Gender, marital status, having children, and debt burden had no correlation with examination success. Backward stepwise multiple regression analysis identified the following independent predictors of ABSITE scores: study location (P < 0.0001), frequency of reading (P = 0.0001), Oldenburg Burnout Inventory exhaustion (P = 0.02), and USMLE step 1 and 2 scores (P = 0.007 and 0.0001, respectively). CONCLUSIONS: Residents who perform higher on the ABSITE have a regular study schedule throughout the year, report less burnout because of exhaustion, study away from home, and have shown success in prior standardized tests. Further study is needed to determine the effects of burnout on clinical duties, career advancement, and satisfaction.

Forkhead box O-1 modulation improves endothelial insulin resistance in human obesity.

OBJECTIVE: Increased visceral adiposity has been closely linked to insulin resistance, endothelial dysfunction, and cardiometabolic disease in obesity, but pathophysiological mechanisms are poorly understood. We sought to investigate mechanisms of vascular insulin resistance by characterizing depot-specific insulin responses and gain evidence that altered functionality of transcription factor forkhead box O-1 (FOXO-1) may play an important role in obesity-related endothelial dysfunction. APPROACH AND RESULTS: We intraoperatively collected paired subcutaneous and visceral adipose tissue samples from 56 severely obese (body mass index, 43 ± 7 kg/m(2)) and 14 nonobese subjects during planned surgical operations, and characterized depot-specific insulin-mediated responses using Western blot and quantitative immunofluorescence techniques. Insulin signaling via phosphorylation of FOXO-1 and consequent endothelial nitric oxide synthase stimulation was selectively impaired in the visceral compared with subcutaneous adipose tissue and endothelial cells of obese subjects. In contrast, tissue actions of insulin were preserved in nonobese individuals. Pharmacological antagonism with AS1842856 and biological silencing using small interfering RNA-mediated FOXO-1 knockdown reversed insulin resistance and restored endothelial nitric oxide synthase activation in the obese. CONCLUSIONS: We observed profound endothelial insulin resistance in the visceral adipose tissue of obese humans which improved with FOXO-1 inhibition. FOXO-1 modulation may represent a novel therapeutic target to diminish vascular insulin resistance. In addition, characterization of endothelial insulin resistance in the adipose microenvironment may provide clues to mechanisms of systemic disease in human obesity.

WNT5A-JNK regulation of vascular insulin resistance in human obesity.

Obesity is associated with the development of vascular insulin resistance; however, pathophysiological mechanisms are poorly understood. We sought to investigate the role of WNT5A-JNK in the regulation of insulin-mediated vasodilator responses in human adipose tissue arterioles prone to endothelial dysfunction. In 43 severely obese (BMI 44±11 kg/m2) and five metabolically normal non-obese (BMI 26±2 kg/m2) subjects, we isolated arterioles from subcutaneous and visceral fat during planned surgeries. Using videomicroscopy, we examined insulin-mediated, endothelium-dependent vasodilator responses and characterized adipose tissue gene and protein expression using real-time polymerase chain reaction and Western blot analyses. Immunofluorescence was used to quantify endothelial nitric oxide synthase (eNOS) phosphorylation. Insulin-mediated vasodilation was markedly impaired in visceral compared to subcutaneous vessels from obese subjects (p<0.001), but preserved in non-obese individuals. Visceral adiposity was associated with increased JNK activation and elevated expression of WNT5A and its non-canonical receptors, which correlated negatively with insulin signaling. Pharmacological JNK antagonism with SP600125 markedly improved insulin-mediated vasodilation by sixfold (p<0.001), while endothelial cells exposed to recombinant WNT5A developed insulin resistance and impaired eNOS phosphorylation (p<0.05). We observed profound vascular insulin resistance in the visceral adipose tissue arterioles of obese subjects that was associated with up-regulated WNT5A-JNK signaling and impaired endothelial eNOS activation. Pharmacological JNK antagonism markedly improved vascular endothelial function, and may represent a potential therapeutic target in obesity-related vascular disease.

Antiangiogenic actions of vascular endothelial growth factor-A165b, an inhibitory isoform of vascular endothelial growth factor-A, in human obesity.

BACKGROUND: Experimental studies suggest that visceral adiposity and adipose tissue dysfunction play a central role in obesity-related cardiometabolic complications. Impaired angiogenesis in fat has been implicated in the development of adipose tissue hypoxia, capillary rarefaction, inflammation, and metabolic dysregulation, but pathophysiological mechanisms remain unknown. In this study, we examined the role of a novel antiangiogenic isoform of vascular endothelial growth factor-A (VEGF-A), VEGF-A165b, in human obesity. METHODS AND RESULTS: We biopsied paired subcutaneous and visceral adipose tissue in 40 obese subjects (body mass index, 45±8 kg/m(2); age, 45±11 years) during bariatric surgery and characterized depot-specific adipose tissue angiogenic capacity using an established ex vivo assay. Visceral adipose tissue exhibited significantly blunted angiogenic growth compared with subcutaneous fat (P<0.001) that was associated with marked tissue upregulation of VEGF-A165b (P=0.004). The extent of VEGF-A165b expression correlated negatively with angiogenic growth (r=-0.6, P=0.006). Although recombinant VEGF-A165b significantly impaired angiogenesis, targeted inhibition of VEGF-A165b with neutralizing antibody stimulated fat pad neovascularization and restored VEGF receptor activation. Blood levels of VEGF-A165b were significantly higher in obese subjects compared with lean control subjects (P=0.02), and surgical weight loss induced a marked decline in serumVEGF-A165b (P=0.003). CONCLUSIONS: We demonstrate that impaired adipose tissue angiogenesis is associated with overexpression of a novel antiangiogenic factor, VEGF-A165b, that may play a pathogenic role in human adiposopathy. Moreover, systemic upregulation of VEGF-A165b in circulating blood may have wider-ranging implications beyond the adipose milieu. VEGF-A165b may represent a novel area of investigation to gain further understanding of mechanisms that modulate the cardiometabolic consequences of obesity.

Patient race and the likelihood of undergoing bariatric surgery among patients seeking surgery.

BACKGROUND: Ethnic minority adults have disproportionately higher rates of obesity than Caucasians but are less likely to undergo bariatric surgery. Recent data suggest that minorities might be less likely to seek surgery. Whether minorities who seek surgery are also less likely to proceed with surgery is unclear. METHODS: We interviewed 651 patients who sought bariatric surgery at two academic medical centers to examine whether ethnic minorities are less likely to proceed with surgery than Caucasians and whether minorities who do proceed with surgery have higher illness burden than their counterparts. We collected patient demographics and abstracted clinical data from the medical records. We then conducted multivariable analyses to examine the association between race and the likelihood of proceeding with bariatric surgery within 1 year of initial interview and to compare the illness burden by race and ethnicity among those who underwent surgery. RESULTS: Of our study sample, 66% were Caucasian, 18% were African-American, and 12% were Hispanics. After adjustment for socioeconomic factors, there were no racial differences in who proceeded with bariatric surgery. Among those who proceeded with surgery, illness burden was comparable between minorities and Caucasian patients with the exception that African-Americans were underrepresented among those with reflux disease (0.4, 95% CI 0.2-0.7) and depression (0.4, 0.2-0.7), and overrepresented among those with anemia (4.8, 2.4-9.6) than Caucasian patients. CONCLUSIONS: Race and ethnicity were not independently associated with likelihood of proceeding with bariatric surgery. Minorities who proceeded with surgery did not clearly have higher illness burden than Caucasian patients.

Effect of Bariatric Weight Loss on the Adipose Lipolytic Transcriptome in Obese Humans.

BACKGROUND: Dysregulated lipolysis has been implicated in mechanisms of cardiometabolic disease and inflammation in obesity. PURPOSE: We sought to examine the effect of bariatric weight loss on adipose tissue lipolytic gene expression and their relationship to systemic metabolic parameters in obese subjects. METHODS/RESULTS: We biopsied subcutaneous adipose tissue in 19 obese individuals (BMI 42 ± 5 kg/m(2), 79% female) at baseline and after a mean period of 8 ± 5 months (range 3-15 months) following bariatric surgery. We performed adipose tissue mRNA expression of proteins involved in triglyceride hydrolysis and correlated their weight loss induced alterations with systemic parameters associated with cardiovascular disease risk. mRNA transcripts of adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), and lipid droplet proteins comparative gene identification 58 (CGI-58) and perilipin increased significantly after weight loss (p < 0.05 for all). ATGL expression correlated inversely with plasma triglyceride (TG), hemoglobin A1C (HbA1C), and glucose, and HSL expression correlated negatively with glucose, while CGI-58 was inversely associated with HbA1C. CONCLUSION: We observed increased expression of adipose tissue lipolytic genes following bariatric weight loss which correlated inversely with systemic markers of lipid and glucose metabolism. Functional alterations in lipolysis in human adipose tissue may play a role in shaping cardiometabolic phenotypes in human obesity.

Seeing is Believing - A Qualitative Study Exploring What Motivates Medical Students to Pursue a Career In General Surgery.

OBJECTIVE: The personal statement (PS) is a rich text in which medical students introduce themselves to the programs to which they are applying. There is no prompt or agreed upon structure for the personal statement. Therefore it represents a window in to medical students' beliefs and perceptions. The goal of this study was to identify what events or experiences motivate medial students to pursue a career in general surgery. Previous work in this area has been largely survey and interview-based. This study is unique in that it looks at what medical students say when not prompted. DESIGN: This is a single-institution, retrospective, qualitative review of applicants' PSs. The PSs were coded based on an a priori coding scheme. The coding scheme was based on published literature of why medical students might apply for a general surgery training position. SETTING: Academic, safety-net hospital. PARTICIPANTS: The study evaluated a subset of the PSs of applications submitted through the Electronic Residency Application Service (ERAS) for a categorical general surgery position in our program during the 2022 match. Specifically, 308 of all received applications were included in this study. This is the subgroup of applications that was pulled out for a close review based on holistic screening of received applications. RESULTS: The single most frequently mentioned motivating factor for applying to general surgery training was the experience a student had on the surgery clerkship. The early years of medical school and sub-internships were less frequently identified as motivating experiences. After the overall clerkship experience, the next most frequent motivating factors were that their personality fit well with the culture of surgery and that they realized the important role surgeons played in patient care. 59 applicants wrote about a pre-existing interest in surgery prior to entering medical school. Most frequently this interest developed after witnessing family or friends or applicant themselves have surgery or shadowing a surgeon. CONCLUSIONS: In this study, students most frequently noted the clerkship experience as having sparked their interest in a career in surgery. Having had exposure to surgeons, through personal experience or shadowing, often led to students to develop an interest in pursuing a career in surgery prior to entering medical school. The findings suggest that to increase the attractiveness of surgery to potential applicants, positive exposure to surgeons and surgery as a field of practice are critical.

Arteriolar function in visceral adipose tissue is impaired in human obesity.

OBJECTIVE: The purpose of this study was to characterize the relationship between adipose tissue phenotype and depot-specific microvascular function in fat. METHODS AND RESULTS: In 30 obese subjects (age 42±11 years, body mass index 46±11 kg/m(2)) undergoing bariatric surgery, we intraoperatively collected visceral and subcutaneous adipose tissue and characterized depot-specific adipose phenotypes. We assessed vasomotor function of the adipose microvasculature using videomicroscopy of small arterioles (75-250 µm) isolated from different fat compartments. Endothelium-dependent, acetylcholine-mediated vasodilation was severely impaired in visceral arterioles, compared to the subcutaneous depot (P<0.001 by ANOVA). Nonendothelium dependent responses to papaverine and nitroprusside were similar. Endothelial nitric oxide synthase inhibition with N(ω)-nitro-l-arginine methyl ester reduced subcutaneous vasodilation but had no effect on severely blunted visceral arteriolar responses. Visceral fat exhibited greater expression of proinflammatory, oxidative stress-related, hypoxia-induced, and proangiogenic genes; increased activated macrophage populations; and had a higher capacity for cytokine production ex vivo. CONCLUSIONS: Our findings provide clinical evidence that the visceral microenvironment may be intrinsically toxic to arterial health providing a potential mechanism by which visceral adiposity burden is linked to atherosclerotic vascular disease. Our findings also support the evolving concept that both adipose tissue quality and quantity may play significant roles in shaping cardiovascular phenotypes in human obesity.

Our Efforts to Create a Welcoming Surgical Residency for LGBTQ Trainees.

OBJECTIVE: To provide a more welcoming environment for LGBTQ residents. DESIGN: This paper is based upon the authors experience creating a training program welcoming to LGBTQ residents. SETTING: University General Surgery Training Program. PARTICIPANTS: Surgical Residents and Surgical Faculty. RESULTS: Over a 9 year period, our residency has made intentional efforts to welcome LGBTQ applicants and support LGBTQ residents. We now have a residency in which over 25% of our residents identify as LGBTQ. CONCLUSIONS: We see opportunities for other residencies to signal to applicants and trainees that they are welcome and celebrated for who they are.

Intern Experience Reflects Information Gathered During the Virtual Interview Process.

OBJECTIVE: The onset of the coronavirus 2019 (COVID-19) pandemic brought many changes to the residency application process including transitioning to a virtual interview platform, which continues today. The transition brought many concerns from general surgery applicants about their ability to obtain adequate information about a program virtually. We sought to characterize how information presented by programs during the first ever virtual interview cycle matched the experience of general surgery interns after training at a program for 1 year. DESIGN, SETTING, AND PARTICIPANTS: In May of 2022, a survey was distributed to 243 program directors who were asked to forward it to their general surgery categorical interns who matched during the 2021 virtual match cycle. Demographics, resources used to determine an impression of a program, and correlations between information presented virtually and what was subsequently experienced as an intern were collected. RESULTS: Forty-six program directors confirmed forwarding the survey to their categorical interns. A total of 102 general surgery interns completed the survey. Most interns (88.2%) agreed that their experience matched expectations based on information received through the virtual interview process and 98% of interns were satisfied with their experience at their training program. Interviews with faculty (40.0%), residents (68.0%) and the program web site (29.0%) were the top 3 resources used to create the most accurate impression of a program. Interns felt they were well informed during the virtual interview experience about support from fellow residents (84.3%), culture (73.0%), surgical volume (72.5%), and intern operative experience (71.6%). In addition, 65.7% of participants thought they were able to obtain a good understanding of the program's culture from the virtual process. However, 16.7% thought that their program unintentionally misrepresented aspects of the training program. CONCLUSIONS: The faculty and residency interviews were the most important factors in program ranking and most participants agreed that their virtual interview experience matched their expectations during their intern year. Most interns felt they were able to obtain a good understanding of the program's culture from the virtual process. In addition, a majority of interns felt well informed during the interview on aspects ranging from surgical volume, autonomy, and work hours to support from faculty and residents. If virtual interviews are to continue, residents can be satisfied that information gathered virtually will match the reality of their training. Programs should continue to make every effort to present their program realistically.

A machine learning framework for optimizing obesity care by simulating clinical trajectories and targeted interventions.

OBJECTIVE: This study aimed to determine the important clinical management bottlenecks that contribute to underuse of weight loss surgery (WLS) and assess risk factors for attrition at each of them. METHODS: A multistate conceptual model of progression from primary care to WLS was developed and used to study all adults who were seen by a primary care provider (PCP) and eligible for WLS from 2016 to 2017 at a large institution. Outcomes were progression from each state to each subsequent state in the model: PCP visit, endocrine weight management referral, endocrine weight management visit, WLS referral, WLS visit, and WLS. RESULTS: Beginning with an initial PCP visit, the respective 2-year Kaplan-Meier estimate for each outcome was 35% (n = 2063), 15.6% (n = 930), 6.3% (n = 400), 4.7% (n = 298), and 1.0% (n = 69) among 5876 eligible patients. Individual providers and clinics differed significantly in their referral practices. Female patients, younger patients, those with higher BMI, and those seen by trainees were more likely to progress. A simulated intervention to increase referrals among PCPs would generate about 49 additional WLS procedures over 3 years. CONCLUSIONS: This study discovered novel insights into the specific dynamics underlying low WLS use rates. This methodology permits in silico testing of interventions designed to optimize obesity care prior to implementation.

Insulin sensitive and resistant obesity in humans: AMPK activity, oxidative stress, and depot-specific changes in gene expression in adipose tissue.

We previously reported that adenosine monophosphate-activated protein kinase (AMPK) activity is lower in adipose tissue of morbidly obese individuals who are insulin resistant than in comparably obese people who are insulin sensitive. However, the number of patients and parameters studied were small. Here, we compared abdominal subcutaneous, epiploic, and omental fat from 16 morbidly obese individuals classified as insulin sensitive or insulin resistant based on the homeostatic model assessment of insulin resistance. We confirmed that AMPK activity is diminished in the insulin resistant group. A custom PCR array revealed increases in mRNA levels of a wide variety of genes associated with inflammation and decreases in PGC-1α and Nampt in omental fat of the insulin resistant group. In contrast, subcutaneous abdominal fat of the same patients showed increases in PTP-1b, VEGFa, IFNγ, PAI-1, and NOS-2 not observed in omental fat. Only angiotensinogen and CD4(+) mRNA levels were increased in both depots. Surprisingly, TNFα was only increased in epiploic fat, which otherwise showed very few changes. Protein carbonyl levels, a measure of oxidative stress, were increased in all depots. Thus, adipose tissues of markedly obese insulin resistant individuals uniformly show decreased AMPK activity and increased oxidative stress compared with insulin sensitive patients. However, most changes in gene expression appear to be depot-specific.

Creating a Welcoming Surgery Residency Training Program for LGBTQ Trainees.

General Surgery residencies have been perceived as unwelcoming to lesbian, gay, bisexual, transgender, and queer (LGBTQ) applicants. Historically, applicants have been reluctant to reveal their LGBTQ status when interviewing for residency positions and LGBTQ surgery residents are more likely to consider leaving their residency. Despite the increased acceptance in society and calls for diversity by governing bodies, there is a perception that the field of surgery is lagging behind. In this article, we summarize the recent literature concerning LGBTQ status in surgery residencies and the impact it has on students and trainees. We then review the recent calls to action to remedy the identified shortcomings. We then share what has been done by our surgery residency, which has been successful in recruiting LGBTQ-identifying residents and summarize recommendation for moving forward.

Structuring Research Rotations to Facilitate Surgery Residents' Academic Productivity.

OBJECTIVE: We sought to enhance opportunities for general surgery residents to conduct research during residency without having to take dedicated time out of clinical training. To this end, we created structured research rotations to facilitate and support resident research. DESIGN: Research blocks of four week's duration were introduced for categorical interns and post-graduate year (PGY) 4 residents. Interns had no clinical responsibilities during their research blocks while PGY 4 residents shadowed their mentor in the clinical setting. Research projects were developed and prepared in advance to maximize productivity during the research rotation. SETTING: General surgery residency program at an urban, academic, safety-net, tertiary care hospital PARTICIPANTS: Categorical general surgery interns and PGY 4 general surgery residents RESULTS: The research rotations were first offered in the 2019 to 2020 academic year (AY). 10 interns and 11 PGY 4 residents have since completed the rotations; of the PGY 4 residents, 6 had not previously taken any time off for research activities. Research projects varied between residents and focused on basic science, clinical outcomes, quality improvement, and education. CONCLUSIONS: Through establishment of dedicated research rotations, we were able to increase resident engagement in a variety of research activities. We provide a simple model for training programs seeking increased research engagement and productivity for their residents without extending training time.

Comparison of weight loss outcomes between Roux-en-Y gastric bypass and sleeve gastrectomy in a racially mixed urban patient population.

BACKGROUND: National data show a trend favoring laparoscopic sleeve gastrectomy (SG) over Roux-en-Y gastric bypass (RYGB). Published data demonstrating the differences in weight loss between the two procedures are mixed. OBJECTIVE: In this retrospective study using clinical data from 2010 to 2020, we compared the clinical and demographic characteristics of patients undergoing either SG or RYGB to evaluate their long-term weight loss outcomes. SETTING: University hospital in the United States. METHODS: A total of 3329 patients were identified in our institutional Metabolic and Bariatric Surgery Accreditation and Quality Improvement database using Current Procedural Terminology codes for either RYGB or SG. A general linear model was used for baseline characteristics. Logistic regression was used for factors favoring RYGB versus SG. A multivariable linear mixed model was used for weight-trajectory analysis. Cox regression was used for a cumulative hazard ratio of 10% weight regained from nadir. RESULTS: Factors favoring RYGB were diagnoses of type 2 diabetes and gastroesophageal reflux disease, Hispanic ethnicity, and surgeon's preference. SG was favored among Black patients and smokers. RYGB was associated with more weight loss at all time points. The risk of weight regain was significantly higher after SG versus RYGB. CONCLUSIONS: The bariatric procedure choice is significantly influenced by race, medical history, and surgeon's experience. RYGB results in a significantly more durable weight loss compared with SG regardless of race or other stratification factors.

Application of the Caprini Risk Assessment Model to Select Patients for Extended Thromboembolism Prophylaxis After Sleeve Gastrectomy.

BACKGROUND: The Caprini risk assessment model is a well-validated tool that identifies patients who would benefit from extended venous thromboembolism (VTE) prophylaxis beyond hospital discharge. VTE, particularly portal mesenteric vein thrombosis (PMVT), is a potentially devastating complication of laparoscopic sleeve gastrectomy (LSG); therefore, we sought to examine whether the model can be safely applied to LSG patients. We hypothesized that its use can minimize the incidence of postoperative VTE, including PMVT, without increasing the likelihood of bleeding complications. MATERIALS AND METHODS: We conducted a retrospective chart review of those patients who underwent LSG at our institution from 2010 and 2018, at which time the Caprini risk assessment model was already our institutional standard. We determined the patients' Caprini scores at the time of discharge and whether patients at high risk of VTE were discharged from hospital on extended courses of VTE prophylaxis. We also recorded if bleeding complications or VTE events occurred in the first 180 days after LSG. RESULTS: Six hundred thirty-eight patients underwent LSG, including 521 (81.7%) women, with an average preoperative body mass index (BMI) of 44.4 kg/m2 (SD 6.8). One hundred fifty-eight (24.8%) patients had Caprini scores that warranted extended courses of VTE prophylaxis beyond hospital discharge. Three patients (0.47%) developed a postoperative VTE, but no patient developed PMVT. No bleeding complications were observed among patients who received extended VTE prophylaxis. CONCLUSION: The Caprini risk assessment model can effectively identify patients after LSG who might benefit from extended courses of VTE prophylaxis. Extended VTE prophylaxis does not seem to confer increased bleeding risk in this patient population.