BACKGROUND:Predicting postoperative body mass index (BMI) trajectories and long-term type 2 diabetes (T2D) remission after bariatric surgery remains challenging. Existing models often rely on baseline variables only and fail to incorporate dynamic postoperative changes. This study aimed to develop and validate a multicentre machine-learning framework that predicts individualized BMI trajectories and T2D remission using routinely available preoperative data and time-dependent weight evolution. METHODS:This multicentre retrospective cohort study included adult patients who underwent Roux-en-Y gastric bypass or sleeve gastrectomy across 11 European centres (2012-2023). Variables with > 30% missing data were excluded; remaining missing values were imputed iteratively. A two-stage approach was used: a regression model predicting postoperative BMI at 3-60 months using an autoregressive design; and a classification model predicting T2D remission using baseline features and predicted BMI trajectories. Internal performance was evaluated with ten-fold and leave-one-clinic-out cross-validation; external validation used an independent cohort from Linköping, Sweden. RESULTS:Of the 11 457 patients initially identified, 9652 patients with complete baseline and follow-up information were used for the analysis. The best BMI model (HistGradientBoosting) achieved a root mean square error (RMSE) of 1.11 kg/m2 (95% confidence interval 1.07 to 1.14) and a mean absolute error (MAE) of 0.62 kg/m2 across clinics; external testing showed an RMSE of 1.12 kg/m2 (95% confidence interval 1.11 to 1.12) and an MAE of 0.63 kg/m2. The T2D remission classifier (XGBoost) obtained a Macro F1 score of 0.88 (precision 0.87, recall 0.88), with an external F1 score of 0.89. Incorporating predicted BMI trajectories improved discrimination compared with baseline-only models (C-index 0.95 versus 0.93). CONCLUSION:A two-stage machine-learning framework has high predictive performance for postoperative BMI and T2D remission up to 5 years after bariatric surgery. Dynamic incorporation of predicted weight trajectories enhances metabolic risk prediction and supports individualized counselling and postoperative management.

There are numerous techniques for right-sided colonic resections with primary ileocolic anastomosis. This study investigated the impact of various access routes and different anastomotic techniques on short- and long-term outcomes. A systematic literature search was performed in CENTRAL (Cochrane Central Register of Controlled Trials), PubMed, and Web of Science (last search December 15, 2025). All randomized clinical trials (RCTs) investigating surgical techniques for right-sided colonic resections (i.e., ileocecal resection, right hemicolectomy) were reviewed. A meta-analysis (random-effects model) was conducted. Risk of bias (Cochrane 2.0) and certainty of evidence (GRADE) were assessed. Thirty-three RCTs with 3787 patients were included. Twelve RCTs (1552 patients) compared open with laparoscopic surgery. Open surgery may result in shorter operation time (MD − 38.75 min, 95

BACKGROUND:Laparoscopic appendectomy has become the standard treatment for acute appendicitis. However, surgical site infections still occur in up to 8% of patients. The aim of this review was to compare the short- and long-term outcomes of an intraumbilical incision with a periumbilical incision for umbilical port placement in laparoscopic appendectomy. METHODS:A systematic literature search for randomized clinical trials (RCTs) was performed in CENTRAL, PubMed, Embase, and Web of Science (last search 10 January 2025). Four outcome variables provided sufficient data to allow for a meta-analysis using the random-effects model. Risk of bias (Cochrane 2.0) and certainty of evidence (GRADE) were assessed. RESULTS:Six RCTs from Asia with 1576 patients were included. An intraumbilical incision may have little to no effect on operation time (MD -1.57 min, 95%-CI: -5.30 to 2.16, p = 0.41, I2 = 98%, and GRADE = very low) and length of hospital stay (MD 0.17 days, 95%-CI: -1.12 to 1.47, p = 0.79, I2 = 93%, and GRADE = very low). Moreover, the evidence suggests that an intraumbilical incision may result in little to no difference in internal organ injury (OR 0.69, 95%-CI: 0.33 to 1.43, p = 0.32, I2 = 0%, and GRADE = low) and umbilical surgical site infection (OR 0.76, 95%-CI: 0.40 to 1.44, p = 0.40, I2 = 22%, and GRADE = low). Five RCTs were assessed as having a high risk of bias, whereas one study raised some concerns. CONCLUSIONS:The evidence suggests that there is little to no difference in any of the clinical short-term outcomes between intraumbilical and periumbilical port placement in laparoscopic appendectomy. Surgeons should use their preferred approach. The body of evidence would benefit from a high-quality RCT in a western population and from data on long-term outcomes. TRIAL REGISTRATION:CRD42025628000 (PROSPERO).

STUDY AIM: To investigate the extent of persistent opioid use among patients undergoing intermediate-to-major elective surgery at a Swiss cantonal hospital and as a secondary aim to identify factors potentially predictive of persistent opioid use (6 to 12 weeks after surgery). METHODS: For this single-centre prospective cohort study, all consecutive patients undergoing elective primary hip arthroplasty, partial or complete prostatectomy, caesarean delivery, spinal surgery, intermediate-to-major visceral surgery or major hand surgery were screened for enrolment from June 2022 to May 2023. We collected basic demographic and medical data, perioperative opioid use (converted to morphine milligram equivalents), postoperative complications, and opioid prescriptions issued by the hospital or other healthcare providers. Telephone interviews about opioid use were conducted with patients 6 weeks after surgery. Only those patients who were still taking opioids at the 6-week interview were contacted 12 weeks after surgery. The primary endpoint was the rate of persistent opioid use 6 or 12 weeks after surgery, and the secondary endpoints were (a) the percentage of patients who received and reported filling prescriptions, and (b) the type and amount of opioids dispensed. With persistent opioid use as the dependent variable, bivariate (predictors: pain or preoperative morphine milligram equivalent) and multivariate logistic regression models were used to assess associations (predictors: age, sex, ASA [American Society of Anesthesiologists] score, preoperative pain). RESULTS: A total of 855 patients were included in the main analysis. Median age was 62 years (interquartile range [IQR] 45–73), 52% were male and postsurgical complications occurred in 51 patients (6%). Fifty-six patients (7%) were preoperative opioid users. At discharge, 40 patients (5%) received an opioid prescription. Of the 724 patients who completed the 6-week follow-up interview, 30 (4%) had filled an opioid prescription (17 hospital-issued, 9 from an external source and 4 from both). Of the 30 patients (4%) who took opioids, the median length of consumption was 7 days (IQR 3–18). Seventeen patients (2%, 9 preoperative users) were taking opioids after 6 weeks. Seven of these 724 patients (1%, 5 preoperative users) continued use at 12 weeks postoperatively. Bivariate logistic regression analyses showed preoperative pain levels (at rest and during movement) were associated with persistent opioid use (odds ratio [OR] 1.27, 95% confidence interval [CI]: 1.11–1.46, p = 0.001; OR 1.3, 95% CI: 1.12–1.5, p = 0.001, respectively), as were 6-week postoperative pain levels (OR 1.96, 95% CI: 1.61–2.39, p <0.0001; OR 1.82, 95% CI: 1.52–2.18, p <0.0001, respectively). The median preoperative morphine milligram equivalent of persistent opioid users was 60 (IQR 30–180) versus 22.5 (IQR 15–30) in non-persistent users (p = 0.0155). There was a slight positive association between higher preoperative morphine milligram equivalent dosage and persistent postoperative opioid use (OR 1.024, 95% CI: 1.003–1.0456, p = 0.023), with a 2.4% increase in the likelihood of prolonged use per morphine milligram equivalent unit. After controlling for potential confounding factors, multivariate logistic regression analyses indicated associations with higher ASA score (OR 11.8, 95% CI: 2.48–56.51, p = 0.002) and preoperative pain levels (OR 1.23, 95% CI: 1.05–1.43, p = 0.008). CONCLUSIONS: Only a small proportion (1%) of surgical patients continued opioid use 12 weeks after intermediate-to-major elective surgery, with an even much lower proportion (0.3%) having been opioid-naive before surgery. This low rate of prolonged opioid use may be due to the restrictive prescription policy of the centre and local healthcare providers.

Background Patients with initial body mass index > 50 kg/m(2) are vastly under-represented in randomized clinical trials demonstrating similar weight loss and diabetes remission rates after sleeve gastrectomy and Roux-en-Y gastric bypass. Methods Propensity score matching 1 : 1 was used to compare outcomes regarding weight loss and diabetes control after sleeve gastrectomy and Roux-en-Y gastric bypass in patients with body mass index > 50 kg/m(2) between 2012 and 2022 in a cohort from 13 centres in six European countries. The primary endpoint was percentage total bodyweight loss; secondary endpoints were diabetes remission rate and rate of persistent body mass index > 40 kg/m(2). Results In total, 3976 of 8160 patients were matched and included in the analysis (1988 in each group). Median age at baseline was 40.0 (range 16-76) years in the sleeve gastrectomy group and 39.5 (15-71) years in the Roux-en-Y gastric bypass group. Median body mass index at baseline was 56.2 (range 50.0-100.0) and 54.3 (50.0-83.9) kg/m(2), respectively (P < 0.001). The follow-up rate was 70.5% at 1 year and 24.4% at 5 years. Percentage total bodyweight loss at 1 and 5 years after sleeve gastrectomy was 30.2 (2.2-63.7) and 25.4 (-4.8 to 56.0)%, respectively, versus 31.2 (7.4-54.5) and 28.2 (-6.6 to 62.9)% in the Roux-en-Y gastric bypass group (P < 0.001 between groups in both time points). The prevalence of persistent body mass index > 40 kg/m(2) after 1 and 5 years was 42.7 and 57.6%, respectively, after sleeve gastrectomy versus 24.5 and 39.2% after Roux-en-Y gastric bypass (P < 0.001 between groups in both time points). A 5-year follow-up, the prevalence of a pathological haemoglobin A1c level (> 6.5%) was 12.9% after sleeve gastrectomy and 11.6% after Roux-en-Y gastric bypass (P = 0.323). Conclusion This study suggests that Roux-en-Y gastric bypass results in greater weight loss than sleeve gastrectomy in patients with body mass index > 50 kg/m(2), whereas improvements in diabetes appear comparable between procedures.

BACKGROUND:The use of abdominal drains in pancreatic surgery, both in partial pancreatoduodenectomy and left pancreatectomy, remains controversial. This study explored the value of routine abdominal drainage on postoperative outcomes. METHODS:A systematic literature search was performed in CENTRAL (Cochrane Central Register of Controlled Trials) and PubMed up to 1 May 2025. All randomized clinical trials (RCTs) investigating the use and management of routine prophylactic abdominal drainage in patients undergoing pancreatic resections were included. A random-effects model for Mantel-Haenszel and inverse-variance analysis was used. Risk of bias (Cochrane 2.0) and certainty of evidence GRADE (Grading of Recommendations, Assessment, Development and Evaluation) were assessed. RESULTS:Thirteen RCTs with 2796 patients were included. Ten RCTs on partial pancreatoduodenectomy with 1744 patients, and seven RCTs on left pancreatectomy with 1052 patients. Four interventions were studied: abdominal drainage versus no abdominal drainage, irrigation-suction versus passive-gravity drainage, closed-suction versus passive-gravity drainage, and early versus late drain removal. Stratification for partial pancreatoduodenectomy and left pancreatectomy was performed, resulting in eight different line-ups. Two line-ups provided sufficient data to allow meta-analysis. Early drainage removal in partial pancreatoduodenectomy, following the study inclusion criteria, was shown to be safe with the additional benefit of significantly reducing chyle leak (odds ratio 0.22, 95% confidence interval (c.i.) 0.08 to 0.59; P < 0.01). The omission of routine abdominal drainage in left pancreatectomy was found to be safe, resulting in fewer postoperative pancreatic fistulas (odds ratio 0.52, 95% c.i. 0.36 to 0.77; P < 0.01) and a shorter hospital stay (mean difference -0.48 days, 95% c.i. -0.61 to -0.35; P < 0.01). CONCLUSION:The present meta-analysis provides level 1a evidence in favour of a selective early drain removal policy in partial pancreatoduodenectomy and a no-drain policy in left pancreatectomy.

INTRODUCTION:Switzerland's aging population and evolving healthcare demands are expected to increase the need for specialized surgeons. Meanwhile, ongoing discussions about reduced work hours for residents and a growing trend toward minimally invasive and outpatient procedures may influence training opportunities and inpatient procedural volumes. The aim of this study was to evaluate workforce, training, and procedural volumes in surgery to determine the future demand for visceral surgeons in Switzerland. METHODS:This study analysed national datasets from 2009 to 2023 to assess trends in medical school enrolments, recognised medical diplomas, residency positions, and the availability of general and visceral surgeons. Additionally, surgical procedure volumes were evaluated with a particular focus on pancreatic surgery as a proxy for complex cases and appendectomies for simple procedures. Linear regression models projected developments up to 2040, incorporating Swiss population growth forecasts. RESULTS:The number of medical diplomas - both Swiss-issued and foreign-recognized - showed an increase from 2,725 in 2011 to 4,647 in 2023. Projections indicate a further rise, reaching over 6,000 by 2040. Although total surgical residency positions declined slightly, spots dedicated to general surgery candidates grew by 8.7%. The overall pool of general surgeons increased from 1'127 in 2009 to 1'557 in 2023, with the proportion of women rising from 10.6 to 24.9% within the same interval. From 2013 to 2023, annual appendectomies increased from 11,529 to 12,412 (7.7% growth), and forecasts project a further rise of approximately 14% by 2040, although the procedures per surgeon are expected to decrease due to ongoing workforce expansion. Visceral surgeons numbered 303 by 2023 (11% female), and forecasts suggest a 50% increase to approximately 462 by 2040. Pancreatic surgery cases grew by 14.5% between 2016 and 2023 and are projected to increase by an additional 25% by 2040. However, the number of complex surgeries per visceral surgeon is projected to decline steadily over the next years. CONCLUSIONS:The expansion of the surgical workforce is projected to overcompensate for the growth of Switzerland's population. In combination with a shift towards outpatient care and reduced working hours, procedural exposure could become critical in general and visceral surgery. Ensuring that training pathways and practice models adapt to these evolving demands will be vital to maintaining high standards of surgical care.

BACKGROUND & AIMS:Immunonutrition is recommended in major abdominal surgery. Evidence is sparse on its effect in minimally invasive procedures. This study aimed to assess its effect on postoperative outcomes in minimally invasive major abdominal surgery. METHODS:CENTRAL, PubMed, EMBASE, and Web of Science were systematically searched (last update: May 28, 2025). All randomized clinical trials (RCTs) investigating immunonutrition versus standard nutrition in patients undergoing minimally invasive major abdominal surgery were included. Mortality, overall and infectious complications, and length of hospital stay (LOS) were analyzed using odds ratios (OR) or mean differences (MD) in a random-effects model. Risk of bias (Cochrane 2.0) and certainty of evidence (GRADE) were assessed. RESULTS:Eleven RCTs comprising 890 patients were included. The overall risk of bias was high in eight RCTs, with some concerns in two and low in one. Immunonutrition may not reduce mortality (OR 1.01, 95 %-CI: 0.2 to 5.08, p = 0.99, I2 = 0 %, GRADE: low). It may have little to no effect on overall (OR 1.25, 95 %-CI: 0.65 to 2.4, p = 0.5, I2 = 60 %, GRADE: very low) or infectious complications (OR 0.75, 95 %-CI: 0.44 to 1.28, p = 0.3, I2 = 32 %, GRADE: very low), and LOS (MD +0.03 days, 95 %-CI: -0.65 to +0.71, p = 0.93, I2 = 47 %, GRADE: very low) but the evidence is very uncertain. These findings persisted after excluding high-risk-of-bias studies (8/11). There was not enough data to analyze higher risk subgroups such as malnourished patients. CONCLUSION:The effects of immunonutrition observed in open surgery are not present in minimally invasive major abdominal surgery, making its routine use in this setting unjustified. High-quality RCTs in nutritionally at-risk patients are warranted.

Background: Postoperative pancreatic fistulas remain a driver of major complications after partial pancreatectomy. It is unclear whether coverage of the anastomosis or pancreatic remnant can reduce the incidence of postoperative pancreatic fistulas. The aim of this study was to evaluate the effect of autologous or artificial coverage of the pancreatic remnant or anastomosis on outcomes after partial pancreatectomy. Methods: A systematic literature search was performed using MEDLINE and the Cochrane Central Register of Controlled Trials (CENTRAL) up to March 2024. All RCTs analysing a coverage method in patients undergoing partial pancreatoduodenectomy or distal pancreatectomy were included. The primary outcome was postoperative pancreatic fistula development. Subgroup analyses for pancreatoduodenectomy or distal pancreatectomy and artificial or autologous coverage were conducted. Results: A total of 18 RCTs with 2326 patients were included. In the overall analysis, coverage decreased the incidence of postoperative pancreatic fistulas by 29% (OR 0.71, 95% c.i. 0.54 to 0.93, P < 0.01). This decrease was also seen in the 12 RCTs covering the remnant after distal pancreatectomy (OR 0.69, 95% c.i. 0.51 to 0.94, P < 0.02) and the 4 RCTs applying autologous coverage after pancreatoduodenectomy and distal pancreatectomy (OR 0.53, 95% c.i. 0.29 to 0.96, P < 0.04). Other subgroup analyses (artificial coverage or pancreatoduodenectomy) showed no statistically significant differences. The secondary endpoints of mortality, reoperations, and re-interventions were each affected positively by the use of coverage techniques. The certainty of evidence was very low to moderate. Conclusion: The implementation of coverage, whether artificial or autologous, is beneficial after partial pancreatectomy, especially in patients undergoing distal pancreatectomy with autologous coverage.

Background The Swiss national union of residents and attendings (VSAO) has voiced its desire for a transition to a 42 + 4h work week, in which 42h be focued on patient care with the remaining 4h be dedicated solely to training purposes. This could potentially result in a decrease of 20% in surgical education time. The current study seeks to address the issues involved in its implementation as well as possible compensatory mechanisms. Methods This mixed methods study seeks to clearly underline the challenges associated with the implementation of a 42 + 4h work week. First, the major stakeholders were identified and analysed via umbrella review. Thereafter, a classic stakeholder analysis was performed. Via morphological matrix, possible models for the implementation of a 42 + 4h work week were developed and evaluated. Finally, representatives from the identified stakeholder groups were interviewed and given the opportunity to provide feedback. Results A total of 26 articles were identified by the literature search and were used to identify the major stakeholders and issues involved in the implementation of the desired work hour regulation. Overall, these showed conflicting results with regard to the effect decreased working hours would have on surgical training and patient outcomes. In the end, the morphological matrix produced three feasible and desirable models for the implementation of a 42 + 4h work week. Each included compensatory mechanisms like auxiliary staff, reduction in administrative tasks, and a switch to EPAs. In their interviews, the stakeholders generally supported these solutions. Conclusion Given the increasing emphasis on the importance of a positive work-life balance, it seems inevitable that the next few years will see the introduction of a 42 + 4h work week in Switzerland. However, it is imperative that every effort be made to preserve the quality of training and patient care for the next generations. This will require the cooperation of all stakeholders in order to find workable solutions.

BackgroundThe pilot study addresses the challenge of predicting postoperative outcomes, particularly body mass index (BMI) trajectories, following bariatric surgery. The complexity of this task makes preoperative personalized obesity treatment challenging.ObjectivesTo develop and validate sophisticated machine learning (ML) algorithms capable of accurately forecasting BMI reductions up to 5 years following bariatric surgery aiming to enhance planning and postoperative care. The secondary goal involves the creation of an accessible web-based calculator for healthcare professionals. This is the first article that compares these methods in BMI prediction.SettingThe study was carried out from January 2012 to December 2021 at GZOAdipositas Surgery Center, Switzerland. Preoperatively, data for 1004 patients were available. Six months postoperatively, data for 1098 patients were available. For the time points 12 months, 18 months, 2 years, 3 years, 4 years, and 5 years the following number of follow-ups were available: 971, 898, 829, 693, 589, and 453.MethodsWe conducted a comprehensive retrospective review of adult patients who underwent bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy), focusing on individuals with preoperative and postoperative data. Patients with certain preoperative conditions and those lacking complete data sets were excluded. Additional exclusion criteria were patients with incomplete data or follow-up, pregnancy during the follow-up period, or preoperative BMI ≤30 kg/m2.ResultsThis study analyzed 1104 patients, with 883 used for model training and 221 for final evaluation, the study achieved reliable predictive capabilities, as measured by root mean square error (RMSE). The RMSE values for three tasks were 2.17 (predicting next BMI value), 1.71 (predicting BMI at any future time point), and 3.49 (predicting the 5-year postoperative BMI curve). These results were showcased through a web application, enhancing clinical accessibility and decision-making.ConclusionThis study highlights the potential of ML to significantly improve bariatric surgical outcomes and overall healthcare efficiency through precise BMI predictions and personalized intervention strategies.

Background: The effects of bariatric metabolic surgery (BMS) on health and comorbidities are wellknown. Socioeconomic factors have been increasingly in focus in recent investigations. Objective: The aim of this study was to analyze the effects of BMS on predictive variables for unemployment. Setting: This study as performed in one reference center for BMS. Patients were treated between 2011 and 2017.Methods: The study design was a retrospective cohort study. Inclusion criteria were Roux-en-Y gastric bypass surgery, follow-up of 60 months, and complete data on employment rate. Exclusion criteria were secondary BMS, secondary referral, loss of follow-up, or patients aged 60 years and above. Patients were stratified as employed independent of part-time work and as unemployed if the patient had no current employment at the time of the visit. Follow-up visits were performed after 6, 12, 24, 48, and 60 months.Results: This study included 623 patients; prior to BMS, 239 (38.36%) patients were employed and 384 (61.64%) unemployed. Risk factors for baseline unemployment included increased body mass index (BMI) (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01 to 1.05; P = .010) and increased American Society of Anesthesiology (ASA) score (OR, 3.55; 95% CI, 2.56 to 4.90; P < .001). Unemployment rate dropped to 32.4% after 24 months (P <.001) and increased to 62.8% after 60 months. The BMI continuously decreased. Following BMS, the unemployment rate was no longer associated with BMI (24 months: OR, 0.97; 95% CI, 0.95 to 1.01; P =.220; 60 months: 1.04; 95% CI, 0.97 to 1.11; P = .269). The initial ASA status remained associated with unemployment (OR, 2.20; 95% CI, 1.60 to 3.01; P <.001). Conclusion: BMI showed some association with the unemployment rate prior to BMI. The unemployment rate significantly decreased 24 months after BMS but increased to baseline values after 60 months. Following BMS, BMI was no longer associated with unemployment. (Surg Obes Relat Dis 2023;19:356-363.)(c) 2023 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.