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.

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.

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.

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.

Update on the Personal and Professional Well-Being of Surgical Residents in New England.

BACKGROUND: Surgical culture has shifted to recognize the importance of resident well-being. This is the first study to longitudinally track regional surgical resident well-being over 5 years. STUDY DESIGN: An anonymous cross-sectional, multi-institutional survey of New England general surgery residents using novel and published instruments to create three domains: health maintenance, burnout, and work environment. RESULTS: Overall, 75% (15 of 20) of programs participated. The response rate was 44% (250 of 570), and 53% (133 of 250) were women, 94% (234 of 250) were 25 to 34 years old, and 71% (178 of 250) were in a relationship. For health maintenance, 57% (143 of 250) reported having a primary care provider, 26% (64 of 250) had not seen a primary care provider in 2 years, and 59% (147 of 250) endorsed being up to date with age-appropriate health screening, but only 44% (109 of 250) were found to actually be up to date. Only 14% (35 of 250) reported exercising more than 150 minutes/week. The burnout rate was 19% (47 of 250), with 32% (81 of 250) and 25% (63 of 250) reporting high levels of emotional exhaustion and depersonalization, respectively. For program directors and attendings, 90% of residents reported that they cared about resident well-being. Eighty-seven percent of residents believed that it was acceptable to take time off during the workday for a personal appointment, but only 49% reported that they would personally take the time. CONCLUSIONS: The personal health maintenance of general surgery residents has changed little over the past five years, despite an overwhelming majority of residents reporting that attendings and program directors care about their well-being. Further study is needed to understand the barriers to improvement of resident wellbeing.

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.

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.

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.

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.

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.

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.