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.

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.

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.

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.

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.

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.

Outcomes in Laparoscopic Roux-en-Y Gastric Bypass and Implications for Surgical Resident Education

OBJECTIVES

Some surgery residents feel inadequately prepared to perform advanced operations, partly due to losing operative opportunities to fellows. In turn, they are prompted to pursue fellowships. Allowing residents the opportunity to participate in advanced procedures and complex cases may alleviate this cycle, if their participation is safe. This study examined the effects of resident participation in laparoscopic Roux-en-Y gastric bypass procedures (LRYGBs).

DESIGN

Our MBSAQIP database was used to identify LRYGBs performed at our institution between 2015 and 2018. Operative notes were reviewed to determine training level of the assistant. Patient comorbidities and outcomes (duration of surgery, length of stay, post-operative complications, readmissions, and reoperations) were stratified by assistant level of training for comparison.

SETTING

Urban tertiary care hospital.

PARTICIPANTS

Trainees and attending surgeons acting as assistants during LRYGBs.

RESULTS

Among 987 total cases, the assistants for the procedures were chief residents (n = 549, 56%), fourth-year residents (n = 258, 26%), attending surgeons (n = 143, 14%), and third-year residents (n = 37, 4%). Attending surgeons assisted more often when patients had a BMI ≥ 45 (38% attendings vs. 25% residents, p = 0.007), ≥ 2 comorbidities (54% vs. 40%, p = 0.007), or had a history of prior bariatric surgery (22% vs. 3%, p < 0.0001).Post-operative complication rate was low (4%) and did not differ significantly between all training levels (p = 0.86). Average length of stay, readmission rates, and reoperation rates were not significantly different across training levels (p = 0.75, p = 0.072, and p = 0.91 respectively).

CONCLUSION

Complication rates, hospital length of stay, readmission rates, and reoperation rates were equivalent for patients regardless of the level of training of the assistant for LRYGBs. Involving residents in complex bariatric procedures such as LRYGB is a safe model of education that does not compromise patient safety or hospital outcomes. Involvement in advanced cases allows general surgery residents to more confidently move toward independent practice.

Efficacy of a resident-as-teacher program (RATP) for general surgery residents: An evaluation of 3 Years of implementation

BACKGROUND

Teaching is a responsibility of general surgery residents and formal teaching instruction is mandated. This study examines the efficacy of a formal RATP incorporated into our general surgery residency curriculum.

METHODS

The RATP was developed locally and delivered longitudinally over the course of the academic year, starting in 2017. Self-assessment surveys were distributed to residents before and after completion of the program each academic year. Medical students were surveyed regarding their impression of teaching on the surgical clerkship.

RESULTS

RATP data was collected annually. All sessions were highly rated. Residents reported improved teaching self-efficacy after participation. Medical student agreement with the statement 'Residents provided effective teaching during the [surgery] clerkship' increased from 68.6% prior to RATP implementation to 79.7% in the following years (p < 0.05).

CONCLUSIONS

Incorporation of a locally developed RATP improved residents' self-perceptions and medical student perception of residents as teachers. RATPs should be adopted widely.

Association of Bariatric Surgery With Vascular Outcomes

IMPORTANCE

Bariatric surgical weight loss is associated with reduced cardiovascular mortality; however, the mechanisms underlying this association are incompletely understood.

OBJECTIVES

To identify variables associated with vascular remodeling after bariatric surgery and to examine how sex, race, and metabolic status are associated with microvascular and macrovascular outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This population-based longitudinal cohort included 307 individuals who underwent bariatric surgery. Participants were enrolled in the bariatric weight loss program at Boston Medical Center, a large, multi-ethnic urban hospital, with presurgical and postsurgical assessments. Data were collected from December 11, 2001 to August 27, 2019. Data were analyzed in September 2019.

EXPOSURE

Bariatric surgery.

MAIN OUTCOMES AND MEASURES

Flow-mediated dilation (FMD) and reactive hyperemia (RH) (as measures of macrovascular and microvascular function, respectively) and clinical variables were measured preoperatively at baseline and at least once postoperatively within 12 months of the bariatric intervention.

RESULTS

A total of 307 participants with obesity (mean [SD] age, 42 [12] years; 246 [80%] women; 199 [65%] White; mean [SD] body mass index, 46 [8]) were enrolled in this study. Bariatric surgery was associated with significant weight loss and improved macrovascular and microvascular function across subgroups of sex, race, and traditional metabolic syndrome (mean [SD] pre- vs postsurgery weight: 126 [25] kg vs 104 [25] kg; P < .001; mean [SD] pre- vs postsurgery FMD: 9.1% [5.3] vs 10.2% [5.1]; P < .001; mean [SD] pre- vs postsurgery RH: 764% [400] vs 923% [412]; P < .001). Factors associated with change in vascular phenotype correlated most strongly with adiposity markers and several metabolic variables depending on vascular territory (eg, association of weight change with change in RH: estimate, -3.2; 95% CI, -4.7 to -1.8; association of hemoglobin A1c with change in FMD: estimate, -0.5; 95% CI, -0.95 to -0.05). While changes in macrovascular function among individuals with metabolically healthy obesity were not observed, the addition of biomarker assessment using high-sensitivity C-reactive protein plasma levels greater than 2 mg/dL identified participants with seemingly metabolically healthy obesity who had low-grade inflammation and achieved microvascular benefit from weight loss surgery.

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that bariatric intervention is associated with weight loss and favorable remodeling of the vasculature among a wide range of individuals with cardiovascular risk. Moreover, differences in arterial responses to weight loss surgery by metabolic status were identified, underscoring heterogeneity in physiological responses to adiposity change and potential activation of distinct pathological pathways in clinical subgroups. As such, individuals with metabolically healthy obesity represent a mixed population that may benefit from more refined phenotypic classification.

A Structured Mentorship Elective Deepens Personal Connections and Increases Scholarly Achievements of Senior Surgery Residents

OBJECTIVES

Surgery residents have few opportunities to work closely with attending surgeons or conduct research during clinical time. We hypothesized that a mentorship elective with a required research project would benefit residents' career development, including their personal connections with faculty mentors, and would help them build their academic portfolio.

DESIGN

We created a mentorship elective designed as a one-on-one apprenticeship. Completion of a scholarly project was a core component of the elective. Residents, faculty, and the most senior resident ('non-mentee') on the same service as the elective resident were interviewed after the completion of their rotation.

SETTING

University-based surgery residency at Boston Medical Center, Boston, MA.

PARTICIPANTS

All 5 residents in postgraduate year 4 (PGY-4) participated in the mentorship elective during the 2019 to 2020 academic year. Residents identified their faculty mentor. All mentees (5/5), most mentors (4/5), and all non-mentees (4/4) were interviewed.

RESULTS

All mentees reported interacting with their mentor daily, performing clinical duties or discussing their research project. For mentees, the top factor when selecting their mentor was the mentor's clinical expertise, and the most valuable aspect of the rotation was developing a relationship with their mentor. All mentors responded that their mentee gained an understanding of running an academic surgical practice and developed research skills. Four of 5 mentees completed critical portions of their scholarly project during the elective with one publishing in a peer-reviewed journal, 2 having their work accepted to a national conference, and one creating vascular surgery educational videos. All stated the elective was valuable.

CONCLUSIONS

A structured apprenticeship rotation allowed for closer relationships with attending surgeons and increased the scholarly achievement of PGY-4 surgery residents. We provide an example of how to incorporate a successful elective rotation into the surgery curriculum that strengthens resident career development and research productivity.

Approach to the Patient: Management of the Post-Bariatric Surgery Patient With Weight Regain

CONTEXT

Weight regain (WR) after bariatric surgery is emerging as a common clinical problem due to the increase in the number of procedures performed. Early interventions are necessary to curtail the potential recurrence of comorbid conditions. However, it is often difficult to recognize WR early enough to introduce mitigating measures because there are no current guidelines for timely diagnosis and assessment of the severity of this condition.

OBJECTIVE

We present a practical approach for the early recognition of WR, based on 11-year follow-up data from our multiethnic bariatric surgery patient population.

METHODS

We classify WR according to the rate of increase in weight relative to nadir weight, normalized per 30-day interval. We also review pertinent literature about the etiologic factors contributing to WR after bariatric surgery.

RESULTS

According to our algorithm, mild, moderate, and rapid WR are defined as weight increases of 0.2% to <0.5%, 0.5% to 1.0%, and more than 1.0% of nadir weight per 30 days, respectively. Treatment options, including dietary counseling, use of antiobesity medication, and consideration of surgical revision, are described. A case is presented to illustrate the utility of timely identification of WR and the importance of collaboration between bariatric surgeons, obesity medicine specialists, and dietitians.

CONCLUSION

Our approach emphasizes the importance of regular long-term follow-up for all bariatric surgery patients.

Surgical management of obstructing clot at the jejunojejunostomy after gastric bypass: a single center experience and literature review

BACKGROUND

Roux-en-Y gastric bypass is a proven treatment for morbid obesity and its sequelae. Gastric bypass has a safe risk profile, but postoperative complications can be seen. We report on 10 cases of postoperative bleeding causing an obstructing clot at the jejunojejunostomy (JJ) occurring over a 9-year period.

OBJECTIVES

The aim was to document presenting symptoms of obstructing clots at the JJ and to suggest a treatment approach to minimize complications.

SETTING

University Hospital, United States METHODS: The local Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database was queried for all patients undergoing reoperation after Roux-en-Y gastric bypass, from July 2009 until December 2019. All patients who were found to have postoperative bleeding causing an obstructing clot at the JJ were selected for retrospective medical-record review.

RESULTS

The most common presenting symptoms were Hematocrit drop (10 of 10), nausea (9 of 10), abdominal pain (7 of 10), and hematemesis (4 of 10). There were 12 reoperations in the 10 patients, 10 of which were completed laparoscopically. Infectious complications were the most frequent morbidity in our patients; 4 patients developed abscesses. In all of these, the operative notes described gross spillage into the peritoneal cavity. In later cases, the remnant stomach was decompressed before reoperation, reducing spillage.

CONCLUSIONS

Despite the low rate of obstructing clots at the JJ, without rapid recognition and reoperation, there is a risk for serious complications. Typical presenting symptoms include nausea and abdominal pain, which help differentiate it from other causes of decreased hematocrit. Diagnosis is commonly made with computerized tomographic (CT) scan. Decompression of a dilated remnant stomach before addressing the clot can prevent intraperitoneal spillage and subsequent abscess formation. Enterotomy creation and removal of clot is recommended, without fear of continued bleeding.

The Boston Medical Center Coronavirus Disease 2019 (COVID-19) Procedure Team: Optimizing the surgeon's role in pandemic care at a safety-net hospital

Background

The coronavirus disease 2019 pandemic has claimed many lives and strained the US health care system. At Boston Medical Center, a regional safety-net hospital, the Department of Surgery created a dedicated coronavirus disease 2019 Procedure Team to ease the burden on other providers coping with the surge of infected patients. As restrictions on social distancing are lifted, health systems are bracing for additional surges in coronavirus disease 2019 cases. Our objective is to quantify the volume and types of procedures performed, review outcomes, and highlight lessons for other institutions that may need to establish similar teams.

Methods

Procedures were tracked prospectively along with patient demographics, immediate complications, and time from donning to doffing of the personal protective equipment. Retrospective chart review was conducted to obtain patient outcomes and delayed adverse events. We hypothesized that a dedicated surgeon-led team would perform invasive bedside procedures expeditiously and with few complications.

Results

From March 30, 2020 to April 30, 2020, there were 1,196 coronavirus disease 2019 admissions. The Procedure Team performed 272 procedures on 125 patients, including placement of 135 arterial catheters, 107 central venous catheters, 25 hemodialysis catheters, and 4 thoracostomy tubes. Specific to central venous access, the average procedural time was 47 minutes, and the rate of immediate complications was 1.5%, including 1 arterial cannulation and 1 pneumothorax.

Conclusion

Procedural complication rate was less than rates reported in the literature. The team saved approximately 192 hours of work that could be redirected to other patient care needs. In times of crisis, redeployment of surgeons (who arguably have the most procedural experience) into procedural teams is a practical approach to optimize outcomes and preserve resources.

Laparoscopic versus open ventral hernia repair in the elderly: a propensity score-matched analysis

BACKGROUND

Ventral hernia repair is common in the expanding aging population, but remains challenging due to their frequent comorbidities. The purpose of this study is to compare the surgical outcomes of open vs. laparoscopic ventral hernia repair in elderly patients.

METHODS

Patients ≥ 65 years of age that underwent elective open or laparoscopic ventral hernia repair were identified from the American College of Surgeons National Surgical Quality Improvement Project (NSQIP) database. To reduce potential selection bias, propensity scores were created for the likelihood of undergoing laparoscopic surgery based on patients' demographics and comorbidities. Patients were matched based on the logit of the propensity scores. Thirty-day surgical outcomes were compared after matching using Chi-square test for categorical variables and the Wilcoxon Rank-Sum test for continuous variables.

RESULTS

35,079 (71.1%) and 14,270 (28.9%) patients underwent open and laparoscopic ventral hernia repairs, respectively. Laparoscopic surgery was associated with a lower overall morbidity (5.9% vs. 9.1%; p < 0.001) compared to open repair. The incidence of surgical site infections (1.1% vs. 3.5%; p < 0.001), post-operative infections (2.7% vs. 3.6%; p < 0.001), and reoperation (1.7% vs. 2.1%; p = 0.009) were all lower after laparoscopic repair. All other major surgical outcomes were either better with laparoscopy or comparable between both treatment groups except for operative time.

CONCLUSION

Although open surgery remains the most prevalent in the elderly population, the results of this study suggest that laparoscopic surgery is safe and associated with a lower risk of overall morbidity, surgical site infections, and reoperation.

The Mitigating Effect of Phentermine and Topiramate on Weight Regain After Roux-en-Y Gastric Bypass Surgery

OBJECTIVE

Weight regain (WR) after Roux-en-Y gastric bypass surgery (RYGB) starts to occur 2 years after surgery, ultimately affecting at least 25% of patients. A limited number of studies have evaluated the impact of antiobesity medications (AOMs) on this phenomenon.

METHODS

This study reviewed the electronic medical records of 1,196 patients who underwent RYGB between 2004 and 2015. WR was evaluated by comparing each patient's weight during subsequent postoperative office visits to nadir weight (lowest weight after RYGB, n = 760), taking into consideration the interval during which WR occurred. Patients who were prescribed AOMs and came to follow-up visits were classified as adherent users, whereas those who missed their follow-up visits were considered nonadherent. This study used a linear mixed model, Cox regression, and generalized equation estimator to determine the impact of AOMs on WR trajectory, hazard ratio for time to event, and odds ratio for repeated event occurrence, respectively.

RESULTS

Despite the lack of a unified protocol for using AOMs, the three statistical models converged to show that phentermine and topiramate, used individually or in combination, can significantly reduce WR after RYGB.

CONCLUSIONS

Phentermine and topiramate are effective in mitigating WR after RYGB. Further studies are needed to help ascertain optimal use of AOMs after bariatric surgery.

Decision Regret up to 4 Years After Gastric Bypass and Gastric Banding

BACKGROUND

Weight loss surgery (WLS) is neither risk-free nor universally effective. Few studies have examined what proportion of patients regret having undergone WLS.

METHODS

We interviewed patients at two WLS centers before and after WLS about weight loss, quality of life/QOL (Impact of Weight on QOL-lite), and decision regret (modified Brehaut Regret scale, range 0-100). We conducted separate multivariable logistic regression models to examine the association between weight loss and ∆QOL scores and having decision regret (score > 50).

RESULTS

Of 205 RYGB patients, only 2.2% (year 1) to 5.1% (year 4, n = 134) reported regret scores > 50 over 4 years; 2.0-4.5% did not think they made the right decision; 2.0-4.5% would not undergo WLS again. In contrast, of 188 gastric banding patients (n = 123 at year 4), 8.2-20.3% had regret scores > 50; 5.9-19.5% did not think they made the right decision; 7.1-19.5% would not undergo WLS again. Weight loss and ∆QOL scores were significant correlates of decision regret after banding although weight loss was a stronger correlate with lower model quasi-likelihood under the independence model criterion score. Four years after banding, mean weight loss for patients with regret scores > 50 was 7.4% vs. 21.1% for those with scores < 50; the AOR for regret score > 50 was 0.90 (95% CI 0.87-0.94) for every 1% greater weight loss. Poor sexual function, but not weight loss or other QOL factors, was significantly correlated with decision regret after RYGB.

CONCLUSION

Few patients regret undergoing RYGB but 20% regret undergoing gastric banding with weight loss being a major driver.

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.

Resident involvement in minimally-invasive vs. open procedures

BACKGROUND

The objective of this study was to evaluate the impact of resident involvement on surgical outcomes in laparoscopic compared to open procedures.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program 2007-2012 was queried for open and laparoscopic ventral hernia repair (VHR), inguinal hernia repair (IHR), splenectomy, colectomy, or cholecystectomy (CCY). Multivariable regression analyses were performed to assess the impact of resident involvement on surgical outcomes.

RESULTS

In total, 88,337 VHR, 20,586 IHR, 59,254 colectomies, 3301 splenectomies, and 95,900 CCY were identified. Resident involvement was predictive for major complication during open VHR (AOR, 1.29; p < 0.001), but not during any other procedure. Resident participation significantly prolonged operative time for open, as well as laparoscopic VHR, IHR, colectomy, splenectomy, and CCY (all p < 0.01).

CONCLUSIONS

The results of this study suggest that resident participation has a similar impact on surgical outcomes during laparoscopic and open surgery, and is generally safe.

Resident-as-Teacher Programs in General Surgery Residency: Context and Characterization

OBJECTIVE

Teaching medical students and junior residents are key components of a surgical resident's role. How surgical residents are formally prepared for their teaching role is not well described. The aim of this study was to characterize the status of formal Resident-as-Teacher Programs (RATPs) in U.S. general surgery residency programs. We also sought to understand current attitudes towards teaching by residents.

DESIGN

A survey regarding the presence of RATPs and attitudes toward teaching by residents was sent through the Association of Program Directors in Surgery (APDS) to general surgery program directors (PDs).

SETTING

The study was conducted using an electronically distributed survey.

PARTICIPANTS

Program directors of general surgery residencies were contacted through the APDS.

RESULTS

Program directors from 105 institutions completed the survey; one did not respond to the question about RATPs. 27 (26%) indicated they utilized a RATP. Of these programs the majority, 25 (93%), were developed at the institution and only 2 (6%) used a published curriculum. For the programs without a RATP, 47 (61%) of PDs indicated they were interested in establishing one. Respondents not interested most often cited other resident obligations and time constraints as limiting factors.

CONCLUSIONS

Fewer than one third of responding programs have an established RATP; of those programs that do not have a RATP, the majority are interested in establishing one. Residents clearly play an important role teaching and PDs acknowledge teaching is an important part of residents' daily job, thus formal preparing residents for their teaching role is important. Development and dissemination of a RATP that can be easily incorporated in to general surgery programs would meet an identified need in general surgery training.

Fat-Specific Protein 27 Regulation of Vascular Function in Human Obesity

Background Pathophysiological mechanisms that connect obesity to cardiovascular disease are incompletely understood. FSP27 (Fat-specific protein 27) is a lipid droplet-associated protein that regulates lipolysis and insulin sensitivity in adipocytes. We unexpectedly discovered extensive FSP27 expression in human endothelial cells that is downregulated in association with visceral obesity. We sought to examine the functional role of FSP27 in the control of vascular phenotype. Methods and Results We biopsied paired subcutaneous and visceral fat depots from 61 obese individuals (body mass index 44±8 kg/m2, age 48±4 years) during planned bariatric surgery. We characterized depot-specific FSP27 expression in relation to adipose tissue microvascular insulin resistance, endothelial function and angiogenesis, and examined differential effects of FSP27 modification on vascular function. We observed markedly reduced vasodilator and angiogenic capacity of microvessels isolated from the visceral compared with subcutaneous adipose depots. Recombinant FSP27 and/or adenoviral FSP27 overexpression in human tissue increased endothelial nitric oxide synthase phosphorylation and nitric oxide production, and rescued vasomotor and angiogenic dysfunction (P<0.05), while siRNA-mediated FSP27 knockdown had opposite effects. Mechanistically, we observed that FSP27 interacts with vascular endothelial growth factor-A and exerts robust regulatory control over its expression. Lastly, in a subset of subjects followed longitudinally for 12±3 months after their bariatric surgery, 30% weight loss improved metabolic parameters and increased angiogenic capacity that correlated positively with increased FSP27 expression (r=0.79, P<0.05). Conclusions Our data strongly support a key role and functional significance of FSP27 as a critical endogenous modulator of human microvascular function that has not been previously described. FSP27 may serve as a previously unrecognized regulator of arteriolar vasomotor capacity and angiogenesis which are pivotal in the pathogenesis of cardiometabolic diseases linked to obesity.

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.

Weight Recidivism After Roux-en-Y Gastric Bypass Surgery: An 11-Year Experience in a Multiethnic Medical Center

OBJECTIVE

Weight recidivism following Roux-en-Y gastric bypass (RYGB) is common and is associated with recurrence of comorbidities. Studies with long-term follow-up of recidivism quantified by weight regain (WR) are lacking. A retrospective review of all RYGB at our center from 2004 to 2015 was performed to examine the effects of race and type 2 diabetes on WR following RYGB.

METHODS

Multivariable linear mixed models were used for the effects of time and race on weight, WR relative to nadir weight (WR/nadir), and WR relative to maximal weight loss, and Cox regressions were used for low, moderate, and high WR/nadir.

RESULTS

A total of 1,395 participants were identified. The sample was limited to African American (AA), Caucasian American (CA), and Hispanic American (HA) participants. The effects of time (P < 0.0001), race (P < 0.0001), and race × time interaction (P = 0.0008) on weight trajectory were significant. AA had significantly more WR than CA (P < 0.01). AA and HA had a higher hazard ratio for having low, moderate, and rapid WR/nadir.

CONCLUSIONS

Racial disparities after RYGB include WR and particularly affect AA. Understanding the etiologic factors that contribute to these disparities is important to optimize the long-term clinical outcomes of bariatric surgery.

Weight Loss After Bariatric Surgery: Do Clinical and Behavioral Factors Explain Racial Differences?

BACKGROUND

Prior studies have suggested less weight loss among African American compared to Caucasian patients; however, few studies have been able to simultaneously account for baseline differences in other demographic, clinical, or behavioral factors.

METHODS

We interviewed patients at two weight loss surgery (WLS) centers and conducted chart reviews before and after WLS. We compared weight loss post-WLS by race/ethnicity and examined baseline demographic, clinical (BMI, comorbidities, quality of life), and behavioral (eating behavior, physical activity level, alcohol intake) factors that might explain observed racial differences in weight loss at 1 and 2 years after WLS.

RESULTS

Of 537 participants who underwent either Roux-en-Y Gastric Bypass (54%) or gastric banding (46%), 85% completed 1-year follow-up and 73% completed 2-year follow-up. Patients lost a mean of 33.00% of initial weight at year 1 and 32.43% at year 2 after bypass and 16.07% and 17.56 % respectively after banding. After adjustment for other demographic characteristics and type of surgery, African Americans lost an absolute 5.93 ± 1.49% less weight than Caucasian patients after bypass (p < 0.001) and 4.72 ± 1.96% less weight after banding. Of the other demographic, clinical, behavioral factors considered, having diabetes and perceived difficulty making dietary changes at baseline were associated with less weight loss among gastric bypass patients whereas having a diagnosis of anxiety disorder was associated with less weight loss among gastric banding patients. The association between race and weight loss did not substantially attenuate with additional adjustment for these clinical and behavioral factors, however.

CONCLUSION

African American patients lost significantly less weight than Caucasian patients. Racial differences could not be explained by baseline demographic, clinical, or behavioral characteristics we examined.

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.

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.

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.

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.

Cyclooxygenase inhibition improves endothelial vasomotor dysfunction of visceral adipose arterioles in human obesity

OBJECTIVE

The purpose of this study was to determine whether cyclooxygenase inhibition improves vascular dysfunction of adipose microvessels from obese humans.

DESIGN AND METHODS

In 20 obese subjects (age 37 ± 12 years, BMI 47 ± 8 kg/m²), subcutaneous and visceral fat were collected during bariatric surgery and characterized for adipose depot-specific gene expression, endothelial cell phenotype, and microvascular function. Vasomotor function was assessed in response to endothelium-dependent agonists using videomicroscopy of small arterioles from fat.

RESULTS

Arterioles from visceral fat exhibited impaired endothelium-dependent, acetylcholine-mediated vasodilation, compared to the subcutaneous depot (P < 0.001). Expression of mRNA transcripts relevant to the cyclooxygenase pathway was upregulated in visceral compared to subcutaneous fat. Pharmacological inhibition of cyclooxygenase with indomethacin improved endothelium-dependent vasodilator function of arterioles from visceral fat by twofold (P = 0.01), whereas indomethacin had no effect in the subcutaneous depot. Indomethacin increased activation via serine-1177 phosphorylation of endothelial nitric oxide synthase in response to acetylcholine in endothelial cells from visceral fat. Inhibition of endothelial nitric oxide synthase with N(ω)-nitro-L-arginine methyl ester abrogated the effects of cyclooxygenase-inhibition suggesting that vascular actions of indomethacin were related to increased nitric oxide bioavailability.

CONCLUSIONS

Our findings suggest that cyclooxygenase-mediated vasoconstrictor prostanoids partly contribute to endothelial dysfunction of visceral adipose arterioles in human obesity.

Patient factors associated with undergoing laparoscopic adjustable gastric banding vs Roux-en-Y gastric bypass for weight loss

BACKGROUND

Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding are 2 commonly performed bariatric procedures in the US with different profiles for risk and effectiveness. Little is known about factors that might lead patients to proceed with one procedure over the other.

STUDY DESIGN

We recruited and interviewed patients seeking bariatric surgery from 2 academic centers in Boston (response rate 70%). We conducted multivariable analyses to identify patient perceptions and clinical and behavioral characteristics that correlated with undergoing gastric banding (n = 239) vs gastric bypass (n = 297).

RESULTS

After adjustment for socio-demographic and clinical factors, we found that older patients (odds ratio [OR] 1.03; 95% CI 1.00 to 1.05) and those with higher quality of life scores and higher levels of uncontrolled eating were more likely to undergo gastric banding as opposed to gastric bypass. In contrast, patients with type 2 diabetes (OR 0.46; 95% CI 0.28 to 0.77), those who desired greater weight loss, and those who were willing to assume higher mortality risk to achieve their ideal weight were less likely to proceed with gastric banding. After initial adjustment, male sex and lower body mass index were associated with a likelihood of undergoing gastric banding; however, these factors were no longer significant after adjustment for other significant correlates such as patients' perceived ideal weight, predilection to assume risk to lose weight, and eating behavior.

CONCLUSIONS

Patients' diabetes status, quality of life, eating behavior, ideal weight loss, and willingness to assume mortality risk to lose weight were associated with whether patients proceeded with gastric banding as opposed to gastric bypass. Other clinical factors were less important.

Insulin status and vascular responses to weight loss in obesity

OBJECTIVES

The aim of this study was to determine whether the effects of weight loss on arterial function are differentially modified by insulin status.

BACKGROUND

Clinical studies suggest that plasma insulin levels may predict the extent of cardiovascular benefit achieved with weight loss in obese individuals, but mechanisms are currently unknown.

METHODS

We prospectively followed 208 overweight or obese patients (body mass index [BMI] ≥25 kg/m(2)) receiving medical/dietary (48%) or bariatric surgical (52%) weight-loss treatment during a median period of 11.7 months (interquartile range: 4.6 to 13 months). We measured plasma metabolic parameters and vascular endothelial function using ultrasound at baseline and following weight-loss intervention and stratified analyses by median plasma insulin levels.

RESULTS

Patients age 45 ± 1 years, with BMI 45 ± 9 kg/m(2), experienced 14 ± 14% weight loss during the study period. In individuals with higher baseline plasma insulin levels (above median >12 μIU/ml; n = 99), ≥10% weight loss (compared with <10%) significantly improved brachial artery macrovascular flow-mediated vasodilation and microvascular reactive hyperemia (p < 0.05 for all). By contrast, vascular function did not change significantly in the lower insulin group (≤12 μIU/ml; n = 109) despite a similar degree of weight loss. In analyses using a 5% weight loss cut point, only microvascular responses improved in the higher insulin group (p = 0.02).

CONCLUSIONS

Insulin status is an important determinant of the positive effect of weight reduction on vascular function with hyperinsulinemic patients deriving the greatest benefit. Integrated improvement in both microvascular and macrovascular function was associated with ≥10% weight loss. Reversal of insulin resistance and endothelial dysfunction may represent key therapeutic targets for cardiovascular risk reduction in obesity.

Expectations for weight loss and willingness to accept risk among patients seeking weight loss surgery

IMPORTANCE

Weight loss surgery (WLS) has been shown to produce long-term weight loss but is not risk free or universally effective. The weight loss expectations and willingness to undergo perioperative risk among patients seeking WLS remain unknown.

OBJECTIVES

To examine the expectations and motivations of WLS patients and the mortality risks they are willing to undertake and to explore the demographic characteristics, clinical factors, and patient perceptions associated with high weight loss expectations and willingness to assume high surgical risk.

DESIGN

We interviewed patients seeking WLS and conducted multivariable analyses to examine the characteristics associated with high weight loss expectations and the acceptance of mortality risks of 10% or higher.

SETTING

Two WLS centers in Boston.

PARTICIPANTS

Six hundred fifty-four patients.

MAIN OUTCOME MEASURES

Disappointment with a sustained weight loss of 20% and willingness to accept a mortality risk of 10% or higher with WLS.

RESULTS

On average, patients expected to lose as much as 38% of their weight after WLS and expressed disappointment if they did not lose at least 26%. Most patients (84.8%) accepted some risk of dying to undergo WLS, but only 57.5% were willing to undergo a hypothetical treatment that produced a 20% weight loss. The mean acceptable mortality risk to undergo WLS was 6.7%, but the median risk was only 0.1%; 19.5% of all patients were willing to accept a risk of at least 10%. Women were more likely than men to be disappointed with a 20% weight loss but were less likely to accept high mortality risk. After initial adjustment, white patients appeared more likely than African American patients to have high weight loss expectations and to be willing to accept high risk. Patients with lower quality-of-life scores and those who perceived needing to lose more than 10% and 20% of weight to achieve "any" health benefits were more likely to have unrealistic weight loss expectations. Low quality-of-life scores were also associated with willingness to accept high risk.

CONCLUSIONS AND RELEVANCE

Most patients seeking WLS have high weight loss expectations and believe they need to lose substantial weight to derive any health benefits. Educational efforts may be necessary to align expectations with clinical reality.

B lymphocytes in human subcutaneous adipose crown-like structures

Accumulation of macrophages and T cells within crown-like structures (CLS) in subcutaneous adipose tissue predicts disease severity in obesity-related insulin resistance (OIR). Although rodent data suggest the B cell is an important feature of these lesions, B cells have not been described within the human CLS. In order to identify B cells in the human subcutaneous CLS (sCLS) in obese subjects and determine whether the presence of B cells predict insulin resistance, we examined archived samples of subcutaneous and omental fat from 32 obese men and women and related findings to clinical parameters. Using immunohistochemistry, we identified B (CD19(+)) and T cells (CD3 (+)) within the sCLS and perivascular space. The presence and density of B cells (B cells per high-power field (pHPF), T cells pHPF, and B cell:T cell (B:T) ratio) were compared with measures of insulin resistance (homeostasis model assessment (HOMA)) and other variables. In 16 of 32 subjects (50%) CD19(+) B cells were localized within sCLS and were relatively more numerous than T cells. HOMA was not different between subjects with CD19(+) vs. CD19(-) sCLS (5.5 vs. 5.3, P = 0.88). After controlling for diabetes and glycemia (hemoglobin A(1c) (HbA(1c))), the B:T ratio correlated with current metformin treatment (r = 0.89, P = 0.001). These results indicate that in human OIR, B cells are an integral component of organized inflammation in subcutaneous fat, and defining their role will lead to a better understanding of OIR pathogenesis and potentially impact treatment.

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.

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.

Endoscopic fundoplication for the treatment of gastroesophageal reflux disease: initial experience

OBJECTIVE

Transoral incisionless fundoplication (TIF) is a promising approach for gastroesophageal reflux disease (GERD) that may decrease morbidity compared with conventional antireflux procedures. We report our initial experience with this minimally invasive approach.

METHODS

Over a 24-month period, 46 patients (mean age, 49 years; 50% female) underwent 48 TIF procedures. All procedures were performed under general anesthesia. Two surgeons participated in all cases; one served as the endoscopist, and the other performed the partial fundoplication. Heartburn severity was measured using the GERD health-related quality of life (GERD-HRQL) instrument (best score = 0, worst score = 45), which includes an additional question assessing overall satisfaction.

RESULTS

Preoperatively, 33 (72%) of 46 patients had small (<3 cm) hiatal hernias, and none had undergone any previous antireflux procedures. Preoperative workup included manometry and barium esophagogram, with pH testing reserved for patients with atypical symptoms or typical symptoms and a lack of response to proton-pump inhibitors. The mean procedure time was 83 minutes (range, 36-180 minutes). The mean procedure time decreased after the first 5 cases from 122 to 78 minutes (P = .001). Mean length of stay was 1.3 days. One patient was readmitted with aspiration pneumonia. Three patients had minor complications (1 had minor bleeding from a suture site and 2 had urinary retention). There were no perioperative deaths. Mean follow-up was 140 days. The mean GERD-HRQL scores improved significantly (23 vs 7; P < .001). There were 22 patients with follow-up greater than 90 days (mean follow-up, 240 days). GERD-HRQL scores remained significantly improved for these patients (23 vs 8; P = .001). Four patients from the entire group (8.6%) had no improvement, in 3 instances due to breakdown of the wrap. Two patients were treated with repeat endoscopic fundoplication and 1 was treated with laparoscopic Nissen fundoplication, and all had a significant improvement in symptoms after reoperation.

CONCLUSIONS

TIF is effective at short-term follow-up and safe for patients with GERD. However, long-term follow-up and randomized trials are required to assess the efficacy and durability of this approach compared with conventional surgical repair.

Vitamin D in adipose tissue and serum 25-hydroxyvitamin D after roux-en-Y gastric bypass

Vitamin D is stored in body fat. The purpose of this study was to determine vitamin D concentration in abdominal fat of obese patients who underwent roux-en-Y gastric bypass (RYGB), and to describe changes in serum 25-hydroxyvitamin D (25(OH)D) levels in relation to loss of body fat. Subjects from a single clinic who were scheduled for RYGB were invited into the study. Abdominal subcutaneous, omental, and mesenteric fat were obtained at time of surgery. Adipose vitamin D(2) and vitamin D(3) concentrations were measured by high-performance liquid chromatography (HPLC). Weight and serum 25(OH)D were assessed at baseline and every 3 months up to 1 year. Seventeen subjects were included, and fat samples were available from eleven. Total vitamin D content in subcutaneous abdominal fat was 297.2 ± 727.7 ng/g tissue, and a wide range was observed (4-2,470 ng/g). Both vitamin D(2) and vitamin D(3) were detected in some of the fat samples. At baseline, 25(OH)D was 23.1 ± 12.6 ng/ml. Average weight loss was 54.8 kg at 12 months, of which ~40 kg was fat mass. Despite daily vitamin D intake of ≥2,500 IU throughout the study, no significant increase in serum 25(OH)D was observed, with mean serum concentration of 25(OH)D at 1 year of 26.2 ± 5.36 ng/ml (P = 0.58). We conclude that vitamin D in adipose tissue does not significantly contribute to serum 25(OH)D despite dramatic loss of fat mass after RYGB.

Reduced adipose tissue inflammation represents an intermediate cardiometabolic phenotype in obesity

OBJECTIVES

The purpose of this study was to determine whether obese individuals with reduced adipose tissue inflammation exhibit a more favorable cardiovascular risk profile.

BACKGROUND

Obesity is associated with a low-grade state of chronic inflammation that might be causally related to cardiometabolic disease.

METHODS

With immunohistochemistry, we categorized obese individuals dichotomously as having inflamed fat (n = 78) or noninflamed fat (n = 31) on the basis of the presence (+) or absence (-) of macrophage crown-like structures (CLS) in subcutaneous abdominal fat biopsy samples. We compared their metabolic, vascular, and adipose tissue characteristics with lean subjects (n = 17).

RESULTS

Inflamed CLS+ obese individuals displayed higher plasma insulin, homeostasis model assessment, triglycerides, glucose, blood pressure, high-sensitivity C-reactive protein, low-density lipoprotein cholesterol, lower high-density lipoprotein cholesterol, and brachial artery flow-mediated dilation compared with lean subjects (p < 0.05). Adipose messenger ribonucleic acid expression of inflammatory genes including CD68, leptin, matrix metalloproteinase-9, CD163, and CD8A were significantly greater and vascular endothelial growth factor was lower in the CLS+ group (p < 0.05). In contrast, obese subjects with noninflamed fat exhibited a mixed clinical phenotype with lower insulin resistance, reduced proatherogenic gene expression, and preserved vascular function as in lean subjects. In multiple linear regression adjusting for age and sex, CLS status (beta = -0.28, p = 0.008) and waist circumference (beta = -0.25, p = 0.03) were independent predictors of flow-mediated dilation.

CONCLUSIONS

These findings lend support to the novel concept that factors in addition to absolute weight burden, such as qualitative features of adipose tissue, might be important determinants of cardiovascular disease. Therapeutic modulation of the adipose phenotype might represent a target for treatment in obesity.

Preoperative weight gain might increase risk of gastric bypass surgery

BACKGROUND

Weight loss improves the cardiovascular and metabolic risk associated with obesity. However, insufficient data are available about the health effects of weight gain, separate from the obesity itself. We sought to determine whether the changes in body weight before open gastric bypass surgery (OGB) would have a significant effect on the immediate perioperative hospital course.

METHODS

A retrospective chart review of 100 consecutive patients was performed to examine the effects of co-morbidities and body weight changes in the immediate preoperative period on the hospital length of stay and the rate of admission to the surgical intensive care unit (SICU).

RESULTS

Of our class III obese patients undergoing OGB, 95% had ≥1 co-morbid condition and an overall SICU admission rate of 18%. Compared with the patients with no perioperative SICU admission, the patients admitted to the SICU had a greater degree of insulin resistance (homeostatic model analysis-insulin resistance 10.8 ± 1.3 versus 5.9 ± 0.5, P = .001), greater serum triglyceride levels (225 ± 47 versus 143 ± 8 mg/dL, P = .003), and had gained more weight preoperatively (.52 ± .13 versus .06 ± .06 lb/wk, P = .003). The multivariate analyses showed that preoperative weight gain was a risk factor for a longer length of stay and more SICU admissions lasting ≥3 days, as were a diagnosis of sleep apnea and an elevated serum triglyceride concentration.

CONCLUSION

The results of the present retrospective study suggest that weight gain increases the risk of perioperative SICU admission associated with OGB, independent of the body mass index. Sleep apnea and elevated serum triglyceride levels were also important determinants of perioperative morbidity. In view of the increasing epidemic of obesity and the popularity of bariatric surgical procedures, we propose that additional clinical and metabolic research focusing on the understanding of the complex relationship among obesity, positive energy balance, weight gain, and perioperative morbidity is needed.

Maladaptive enlargement of the brachial artery in severe obesity is reversed with weight loss

Maladaptive peripheral arterial remodeling, which leads to large arteries with low shear stress, may be associated with increased cardiovascular risk. We tested the hypothesis that arterial enlargement in severe obesity represents maladaptive remodeling and that weight reduction would reverse this process. We evaluated brachial arterial diameter and flow using ultrasound in 244 severely obese patients (age 44 +/- 11 years, 80% female, body mass index (BMI) 46 +/- 9 kg/m) at baseline and in a group of 67 subjects who experienced weight loss at 1 year. Higher BMI was associated with larger brachial artery diameter (p = 0.01) and lower shear stress (p = 0.008), indicating maladaptive remodeling. Significant (> or = 10%) weight reduction was associated with a decrease in resting arterial diameter (-0.19 +/- 0.47 mm, p = 0.02) along with a trend toward increased shear stress. Decreased systemic inflammation was associated with weight loss-induced reverse remodeling of the brachial artery. Our findings demonstrate the presence of maladaptive arterial remodeling in advanced obesity that was ameliorated by significant weight loss.

Long-term successful weight loss improves vascular endothelial function in severely obese individuals

Obesity is associated with increased cardiovascular risk. Although short-term weight loss improves vascular endothelial function, longer term outcomes have not been widely investigated. We examined brachial artery endothelium-dependent vasodilation and metabolic parameters in 29 severely obese subjects who lost > or =10% body weight (age 45 +/- 13 years; BMI 48 +/- 9 kg/m(2)) at baseline and after 12 months of dietary and/or surgical intervention. We compared these parameters to 14 obese individuals (age 49 +/- 11 years; BMI 39 +/- 7 kg/m(2)) who failed to lose weight. For the entire group, mean brachial artery flow-mediated dilation (FMD) was impaired at 6.7 +/- 4.1%. Following sustained weight loss, FMD increased significantly from 6.8 +/- 4.2 to 10.0 +/- 4.7%, but remained blunted in patients without weight decline from 6.5 +/- 4.0 to 5.7 +/- 4.1%, P = 0.013 by ANOVA. Endothelium-independent, nitroglycerin-mediated dilation (NMD) was unaltered. BMI fell by 13 +/- 7 kg/m(2) following successful weight intervention and was associated with reduced total and low-density lipoprotein cholesterol, glucose, hemoglobin A(1c), and high-sensitivity C-reactive protein (CRP). Vascular improvement correlated most strongly with glucose levels (r = -0.51, P = 0.002) and was independent of weight change. In this cohort of severely obese subjects, sustained weight loss at 1 year improved vascular function and metabolic parameters. The findings suggest that reversal of endothelial dysfunction and restoration of arterial homeostasis could potentially reduce cardiovascular risk. The results also demonstrate that metabolic changes in association with weight loss are stronger determinants of vascular phenotype than degree of weight reduction.

Weight loss surgery eligibility according to various BMI criteria among adolescents

A BMI cutoff point at the 99th percentile for age and gender or at 40 kg/m(2) has been suggested for more aggressive treatment of adolescent obesity. The main objective of this study was to determine the proportion of adolescents eligible for weight loss surgery (WLS) based on various BMI cutoff points. Data was extracted from the electronic medical record database of an urban pediatric ambulatory care center over 4 years. National data were used to calculate BMI percentiles (Centers for Disease Control and Prevention (CDC), 2000). Eligibility for WLS was based on a BMI percentile criterion (>or=99th percentile) or the adult WLS cutoff point (>or=40 kg/m(2)). The sample consisted of 3,220 adolescents aged 12-17.9 years, of which 53% were female, 55% were of black race, and 17% of Hispanic ethnicity. Overall, 88 (3%) adolescents had a BMI >or=40 kg/m(2) and 236 (7%) had a BMI >or=99th percentile (P < 0.001). All adolescents with BMI >or=40 kg/m(2) had a BMI >or=99th percentile. A total of 159/2,007 (8%) of 12-14.9-year olds had a BMI >or=99th percentile compared with 77/1,213 (6%) 15-17.9-year olds (P = 0.10), whereas 43/2,007 (2%) of 12-14.9-year olds had a BMI >or=40 kg/m(2) compared with 45/1,213 (4%) 15-17.9-year olds (P = 0.003). In summary, a relatively large proportion of adolescents from a diverse urban population would qualify for WLS based on the percentile criterion. Fewer adolescents would be eligible based on the adult WLS criterion, and younger adolescents would be less likely to be eligible for WLS than older adolescents.

Integrating simulation into a surgical residency program

OBJECTIVE

Surgical training programs nationwide are struggling with the integration of simulation training into their curriculum given the constraints of the 80-h work week. We examine the effectiveness of voluntary training in a simulation lab as part of the surgical curriculum.

METHODS

The ProMIS simulator was introduced into the general surgery residency at Boston University Medical Center. All categorical residents (28) and non-categorical residents (23) were offered a 2-h training session and curriculum review. After the introductory session, time spent in the lab was encouraged, but voluntary. Use of the simulator was tracked for all residents. Participation in the simulation curriculum was defined as three or more uses of the simulator. After 3 months, all residents completed a survey regarding the simulation lab and their simulator usage.

RESULTS

Twenty-six (93%) categorical residents and three (6%) non-categorical residents completed the introductory simulator training session. Over a 3 month period, use of the simulator at least once was 31% among all eligible residents; 80% of postgraduate year (PGY)1, 40% of PGY2, 60% of PGY3, and 0% of PGY4 and PGY5. Four residents (14%) participated in the simulation curriculum. Overall, 70% of simulator usage was during working hours, and 30% was completed post-call or when the resident was off duty. Most residents agreed that the simulator was easy to use and that its use improved their operative skills, but they did not think it was a good substitute for actual operative experience. Reported reasons for not using the simulator included off-site rotation (44%), no time (30%), and no interest (11%).

CONCLUSIONS

Voluntary use of a surgical simulation lab leads to minimal participation in a training curriculum. Participation should be mandatory if it is to be an effective part of a residency curriculum.