Comparative analysis of linear- and circular-stapled gastrojejunostomies in Roux-en-Y gastric bypass: a focus on postoperative morbidity using the comprehensive complication index.

PURPOSE: The linear-stapled (LSA) and the circular-stapled anastomosis (CSA) are the two most commonly performed techniques for the gastrojejunostomy (GJ) during laparoscopic Roux-en-Y gastric bypass (RYGB). This study compared the outcome after both techniques with special focus on postoperative morbidity using the comprehensive complication index (CCI). METHODS: Five hundred eighty-eight patients operated between 01/2010 and 12/2019 were included in the final analysis and divided in two cohorts according to the surgical technique of the GJ (LSA (n = 290) or CSA (n = 298)). Before 09/2016, the CSA was exclusively performed for the GJ, while after 09/2016, the LSA was solely used. RESULTS: The mean CCI for patients with Clavien-Dindo complication grade ≥ 2 within the first 90 days after RYGB was 31 ± 9.1 in the CSA and 25.7 ± 6.8 in the LSA group (p < 0.001), both values still below the previously published benchmark cutoff (≤ 33.73). The C-reactive Protein (CRP)-levels on postoperative days (POD) 1 and 3 as well as the use of opioids on POD 1 were significantly higher in the CSA- than in the LSA-group (all p < 0.001). There were significantly more internal herniations in the CSA group during the first 24 postoperative months (p < 0.001). CONCLUSION: Patients after RYGB with CSA were found to have higher CCI values during the first 90 PODs compared to patients in which the LSA was applied. To achieve optimal outcomes in terms of patient morbidity, the LSA seems to be the superior technique for GJ in RYGB.

Global Outcomes Benchmarks in Laparoscopic Liver Surgery for Segments 7 and 8: International Multicenter Analysis.

BACKGROUND: In recent years, there has been growing interest in laparoscopic liver resection (LLR) and the audit of the results of surgical procedures. The aim of this study was to define reference values for LLR in segments 7 and 8. METHODS: Data on LLR in segments 7 and 8 between January 2000 and December 2020 were collected from 19 expert centers. Reference cases were defined as no prior hepatectomy, ASA <3, body mass index <35 kg/m2, no chronic kidney disease, no cirrhosis and portal hypertension, no chronic obstructive pulmonary disease (FEV1<80%), and no cardiac disease. Reference values were obtained from the 75th percentile of the medians of all reference centers. RESULTS: Of 585 patients, 461 (78.8%) met the reference criteria. The overall complication rate was 27.5% (6% were Clavien-Dindo≥3a) with a mean CCI of 7.5 ± 16.5. At 90-day follow-up, the references values for overall complications were 31%, Clavien≥3a 7.4%, conversion 4.4%, hospital stay < 6 days, and readmission rate < 8.33%, respectively. Eastern centers patients categorized as low risk had a lower rate of overall complications (20.9% vs 31.2%, p=0.01) with similar Clavien-Dindo≥3a (5.5% and 4.8%, p=0.83) compared to Western centers, respectively. CONCLUSION: This study shows the need to establish standards for the postoperative outcomes in LLR based on the complexity of the resection and the location of the lesions.

Global benchmarks in primary robotic bariatric surgery redefine quality standards for Roux-en-Y gastric bypass and sleeve gastrectomy.

BACKGROUND: Whether the benefits of the robotic platform in bariatric surgery translate into superior surgical outcomes remains unclear. The aim of this retrospective study was to establish the 'best possible' outcomes for robotic bariatric surgery and compare them with the established laparoscopic benchmarks. METHODS: Benchmark cut-offs were established for consecutive primary robotic bariatric surgery patients of 17 centres across four continents (13 expert centres and 4 learning phase centres) using the 75th percentile of the median outcome values until 90 days after surgery. The benchmark patients had no previous laparotomy, diabetes, sleep apnoea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, history of thromboembolic events, BMI greater than 50 kg/m2, or age greater than 65 years. RESULTS: A total of 9097 patients were included, who were mainly female (75.5%) and who had a mean(s.d.) age of 44.7(11.5) years and a mean(s.d.) baseline BMI of 44.6(7.7) kg/m2. In expert centres, 13.74% of the 3020 patients who underwent primary robotic Roux-en-Y gastric bypass and 5.9% of the 4078 patients who underwent primary robotic sleeve gastrectomy presented with greater than or equal to one complication within 90 postoperative days. No patient died and 1.1% of patients had adverse events related to the robotic platform. When compared with laparoscopic benchmarks, robotic Roux-en-Y gastric bypass had lower benchmark cut-offs for hospital stay, postoperative bleeding, and marginal ulceration, but the duration of the operation was 42 min longer. For most surgical outcomes, robotic sleeve gastrectomy outperformed laparoscopic sleeve gastrectomy with a comparable duration of the operation. In robotic learning phase centres, outcomes were within the established benchmarks only for low-risk robotic Roux-en-Y gastric bypass. CONCLUSION: The newly established benchmarks suggest that robotic bariatric surgery may enhance surgical safety compared with laparoscopic bariatric surgery; however, the duration of the operation for robotic Roux-en-Y gastric bypass is longer.

Assessing daily energy intake in adult women: validity of a food-recognition mobile application compared to doubly labelled water.

Accurate dietary assessment is crucial for nutrition and health research. Traditional methods, such as food records, food frequency questionnaires, and 24-hour dietary recalls (24HR), have limitations, such as the need for trained interviewers, time-consuming procedures, and inaccuracies in estimations. Novel technologies, such as image-based dietary assessment apps, have been developed to overcome these limitations. SNAQ is a novel image-based food-recognition app which, based on computer vision, assesses food type and volume, and provides nutritional information about dietary intake. This cross-sectional observational study aimed to investigate the validity of SNAQ as a dietary assessment tool for measuring energy and macronutrient intake in adult women with normal body weight (n = 30), compared to doubly labeled water (DLW), a reference method for total daily energy expenditure (TDEE). Energy intake was also estimated using a one-day 24HR for direct comparison. Bland-Altman plots, paired difference tests, and Pearson's correlation coefficient were used to assess agreement and relationships between the methods. SNAQ showed a slightly higher agreement (bias = -329.6 kcal/day) with DLW for total daily energy intake (TDEI) compared to 24HR (bias = -543.0 kcal/day). While both SNAQ and 24HR tended to underestimate TDEI, only 24HR significantly differed from DLW in this regard (p < 0.001). There was no significant relationship between estimated TDEI and TDEE using SNAQ (R2 = 27%, p = 0.50) or 24HR (R2 = 34%, p = 0.20) and there were no significant differences in energy and macronutrient intake estimates between SNAQ and 24HR (Δ = 213.4 kcal/day). In conclusion, these results indicate that SNAQ provides a closer representation of energy intake in adult women with normal body weight than 24HR when compared to DLW, but no relationship was found between the energy estimates of DLW and of the two dietary assessment tools. Further research is needed to determine the clinical relevance and support the implementation of SNAQ in research and clinical settings. Clinical trial registration: This study is registered on ClinicalTrials.gov with the unique identifier NCT04600596 (https://clinicaltrials.gov/ct2/show/NCT04600596).

Attitudes of primary care physicians toward bariatric surgery: a free word association networks analysis.

BACKGROUND: Primary care physicians (PCPs) hold major responsibility in referring patients with obesity eligible for bariatric surgery (BS). OBJECTIVE: The aim was to explore PCPs' mental representation of BS in order to identify barriers and catalysts of BS referral practices. SETTING: Switzerland. METHODS: A total of 3526 PCPs were invited to participate in an online survey. PCPs were asked to write the first 5 words that came to their mind about the term "bariatric surgery." Additionally, they had to pick 2 emotions that best described each provided association. Demographic data and obesity-related referral patterns were collected. Mental representation network was constructed based on co-occurrence of associations, using validated data-driven methodology. RESULTS: In all, 216 PCPs completed the study (response rate: 6.13%). Respondents were aged 55 ± 9.8 years, had an equal sex distribution, and practiced mainly in urban settings. Three mental representations of BS emerged: indication-focused (most frequent associations: "obesity," "diabetes"), treatment-focused ("gastric bypass," "weight loss"), and outcome-focused ("complications," "challenging follow-up"). The emotional label "interested" was used significantly more frequently in the treatment-focused group. Comparison of PCPs among mental modules showed that those with a treatment-focused mindset referred patients for BS most frequently and were significantly more willing to follow up with postbariatric patients (χ2 = 17.8, P = .022). CONCLUSIONS: PCPs think about BS along 3 mental representations, and the treatment-focused attitude was coupled with the highest willingness to refer eligible patients for BS. Confidence in performing postbariatric follow-up was identified as catalyst of BS referral. Access to optimal care for patients with obesity may be improved accordingly.

Young-IFSO Bariatric/Metabolic Surgery Training and Education Survey.

BACKGROUND: This international Young-IFSO survey aims to address variations, trends, and obstacles in bariatric/metabolic surgery (BMS) training globally, since expectations and resources differ among young surgeons. METHODS: The Young-IFSO scientific team designed an online confidential questionnaire with 50 questions analyzing the individual BMS training. The survey link was sent to all IFSO/ASMBS members and was shared in social media. All Young-IFSO members (age up to 45 years) were invited to participate between 16 December 2022 and 4 February 2023. RESULTS: A total of 240 respondents from 61 countries took the survey. Most respondents (70.24%) described their current position as a consultant surgeon with an average of 5.43 years' experience working in BMS, and 55% are working in a bariatric center of excellence. More than 50% of the respondents performed none or less than 10 BMS during residency. Preparation of the stomach and stapling during sleeve gastrectomy (SG) were the first steps performed, and SG was the first BMS completed as a first operating surgeon by most of the respondents (74%). In total, 201 (84.45%) surgeons reported to perform scientific work. Most respondents (90.13%) reported that surgical mentorship had improved their surgical skills. CONCLUSION: This international experts' survey underlines the lack of a standardized global surgical curriculum of BMS during residency. It shows that SG is the single most performed procedure by young surgeons. These data might underline the importance of advancing surgical education in BMS, and accredited fellowship programs should be offered globally to maintain and raise quality of BMS.

Novel Insights into the Physiology of Nutrient Sensing and Gut-Brain Communication in Surgical and Experimental Obesity Therapy.

Despite standardized surgical technique and peri-operative care, metabolic outcomes of bariatric surgery are not uniform. Adaptive changes in brain function may play a crucial role in achieving optimal postbariatric weight loss. This review follows the anatomic-physiologic structure of the postbariatric nutrient-gut-brain communication chain through its key stations and provides a concise summary of recent findings in bariatric physiology, with a special focus on the composition of the intestinal milieu, intestinal nutrient sensing, vagal nerve-mediated gastrointestinal satiation signals, circulating hormones and nutrients, as well as descending neural signals from the forebrain. The results of interventional studies using brain or vagal nerve stimulation to induce weight loss are also summarized. Ultimately, suggestions are made for future diagnostic and therapeutic research for the treatment of obesity.

The Effect of a Multifaceted Intervention Including Classroom Education and Bariatric Weight Suit Use on Medical Students' Attitudes toward Patients with Obesity.

INTRODUCTION: Weight bias refers to negative attitudes toward individuals because of their weight. Evidence-based strategies to successfully reduce weight bias in medical students are lacking. The purpose of this study was to investigate the impact of a multifaceted intervention on medical students' attitudes toward patients with obesity. METHODS: Third and fourth year medical students (n = 79), who enrolled in an 8-week graduate course focusing on the various epidemiologic, physiological, and clinical aspects of obesity, including a gamification task with bariatric weight suits (BWSs), were asked to complete the Nutrition, Exercise and Weight Management (NEW) Attitudes Scale questionnaire pre- and post-course. The inclusion period was between September 2018 and June 2021 and covered 4 consecutive groups of students. RESULTS: The overall NEW Attitudes Scale scores did not change significantly pre- versus post-intervention (pre-course: 19.59, post-course: 24.21, p value = 0.24). However, the subgroup of 4th year medical students showed a significant improvement in their attitudes (pre-course: 16.4, post-course: 26.16, p value = 0.02). The Thurstone rating of 9 out of 31 individual survey items changed significantly from pre- to post-course with a moderate strength (Cramer's V >0.2), including 5 items showing weight bias reduction. The disagreement with the statement "overweight/obese individuals lack willpower" increased from 37 to 68%. CONCLUSION: These findings suggest that in medical students with a low level of weight bias at baseline, a semester course on obesity combined with BWS use affects only a limited number of items of the NEW Attitudes Scale questionnaire. The sensitization of medical students to weight stigma has the potential to improve quality of healthcare for patients with obesity.

Post-bariatric changes in ingestive behavior: Shift in macronutrient preferences in rats and dynamic adaptation of the within-meal microstructure in humans.

This invited review is based on a presentation given at the Annual Meeting of the Society for the Study of Ingestive Behavior in July 2022 and provides the summary of two recent studies on changes in ingestive behavior following bariatric surgery (BS). First, long-term changes in daily absolute and relative macronutrient intake are reported in a rodent model of Roux-en-Y gastric bypass (RYGB). Rats undergoing RYGB progressively decreased their daily calorie- and daily fat intake compared to their preoperative baseline and to the intake of sham operated animals. Second, postbariatric changes in the within-meal ingestive microstructure are portrayed, based on longitudinal data collected in RYGB patients using a drinkometer. The post-RYGB meal size showed a dynamic adjustment process, with the highest decrease in the early postoperative phase, followed by a steady convalescence up to 1-year, at which point the meal size of RYGB patients became comparable to the normal weight adults'. Results are contextualized and contrasted to recent reports on the effect of BS on taste and food choices and consumption. The showcased evidence supports the role of ingestive adaptation and learning in the achievement of reduced calorie intake after RYGB, both in humans and in rodents. The reorganized upper-gastrointestinal anatomy supposedly leads to increased postingestive caloric sensibility, which might be an important behavioral mediator of decreased postbariatric meal size and consequent weight loss.

Classification of Adverse Events in Adult Surgery.

Successful surgery combines quality (achievement of a positive outcome) with safety (avoidance of a negative outcome). Outcome assessment serves the purpose of quality improvement in health care by establishing performance indicators and allowing the identification of performance gaps. Novel surgical quality metric tools (benchmark cutoffs and textbook outcomes) provide procedure-specific ideal surgical outcomes in a subgroup of well-defined low-risk patients, with the aim of setting realistic and best achievable goals for surgeons and centers, as well as supporting unbiased comparison of surgical quality between centers and periods of time. Validated classification systems have been deployed to grade adverse events during the surgical journey: (1) the ClassIntra classification for the intraoperative period; (2) the Clavien-Dindo classification for the gravity of single adverse events; and the (3) Comprehensive Complication Index (CCI) for the sum of adverse events over a defined postoperative period. The failure to rescue rate refers to the death of a patient following one or more potentially treatable postoperative adverse event(s) and is a reliable proxy of the institutional safety culture and infrastructure. Complication assessment is undergoing digital transformation to decrease resource-intensity and provide surgeons with real-time pre- or intraoperative decision support. Standardized reporting of complications informs patients on their chances to realize favorable postoperative outcomes and assists surgical centers in the prioritization of quality improvement initiatives, multidisciplinary teamwork, surgical education, and ultimately, in the enhancement of clinical standards.

[Healthcare cost reimbursement without application-Experiences of a German bariatric service]. / Kostenübernahme bariatrischer Operationen ohne Antragstellung ­ Erfahrungen in einem deutschen Adipositaszentrum.

BACKGROUND: Only a small proportion of patients with morbid obesity in Germany have access to the currently most effective treatment, bariatric surgery. A major reason for this is the restrictive attitude of health insurance companies regarding the reimbursement of costs. OBJECTIVE: To record the postoperative rate of cost coverage by health insurance companies without the currently common preoperative application for morbidly obese patients who received a guideline-indicated bariatric surgery. METHODS: The process of postoperative reimbursement was evaluated through a prospective database over a 2-year period. Cases of primary reimbursement were correlated with respect to age, BMI, comorbidities and membership of a specific health insurance company. Rejected coverage cases were followed up for further advocacy and social court process. RESULTS: A total of 188 patients underwent bariatric surgery as indicated in the guidelines without prior application. Primary cost coverage was achieved in 76.6% (n = 144). There was no correlation with BMI, comorbidities or health insurance affiliation. Patients over 40 years of age were significantly more likely to be covered for costs. For patients without postoperative cost coverage, an out of court settlement was reached in 7 cases, 8 cases were heard by the social courts and 29 cases were still being processed by lawyers. CONCLUSION: Despite the relatively high rate of primary cost coverage, this analysis also shows the restrictive attitude of the health insurance companies regarding bariatric surgery with corresponding economic pressure on the service providers. The consistent implementation of application-free surgery seems necessary to increase the political pressure on health insurers and social courts.

Novel Benchmark Values for Redo Liver Transplantation: Does the Outcome Justify the Effort?

OBJECTIVE: To define benchmark cutoffs for redo liver transplantation (redo-LT). BACKGROUND: In the era of organ shortage, redo-LT is frequently discussed in terms of expected poor outcome and wasteful resources. However, there is a lack of benchmark data to reliably evaluate outcomes after redo-LT. METHODS: We collected data on redo-LT between January 2010 and December 2018 from 22 high-volume transplant centers. Benchmark cases were defined as recipients with model of end stage liver disease (MELD) score ≤25, absence of portal vein thrombosis, no mechanical ventilation at the time of surgery, receiving a graft from a donor after brain death. Also, high-urgent priority and early redo-LT including those for primary nonfunction (PNF) or hepatic artery thrombosis were excluded. Benchmark cutoffs were derived from the 75th percentile of the medians of all benchmark centers. RESULTS: Of 1110 redo-LT, 373 (34%) cases qualified as benchmark cases. Among these cases, the rate of postoperative complications until discharge was 76%, and increased up to 87% at 1-year, respectively. One-year overall survival rate was excellent with 90%. Benchmark cutoffs included Comprehensive Complication Index CCI ® at 1-year of ≤72, and in-hospital and 1-year mortality rates of ≤13% and ≤15%, respectively. In contrast, patients who received a redo-LT for PNF showed worse outcomes with some values dramatically outside the redo-LT benchmarks. CONCLUSION: This study shows that redo-LT achieves good outcome when looking at benchmark scenarios. However, this figure changes in high-risk redo-LT, as for example in PNF. This analysis objectifies for the first-time results and efforts for redo-LT and can serve as a basis for discussion about the use of scarce resources.

Early Postoperative Exposure to High-Fat Diet Does Not Increase Long-Term Weight Loss or Fat Avoidance After Roux-en-Y Gastric Bypass in Rats.

Background: Bariatric surgery alters food preferences in rats and reportedly decreases desire to consume high-fat high-sugar food in humans. The aim of this study was to investigate whether early post-operative exposure to high-fat food could increase body weight loss after Roux-en-Y gastric bypass (RYGB) by triggering fat avoidance. Methods: Male Wistar rats underwent either RYGB (n = 15) or sham-operations (n = 16). Preoperatively a standardized 4-choice cafeteria diet [dietary options: low-fat/low-sugar (LFLS), low-fat/high-sugar (LFHS), high-fat/low-sugar (HFLS), high-fat/high-sugar (HFHS)] was offered. First, each option was available for 4 days, thereafter rats were offered the 4 options simultaneously for 3 days preoperatively. Post-surgery, 8 rats in the RYGB- and 8 in the sham-group were exposed to a high-fat content diet (Oatmeal + 30% lard, OM+L) for 10 days, while 7 RYGB rats and 8 sham-rats received OM alone. From the 11th postoperative day, the 4-choice cafeteria diet was reintroduced for 55-days. The intake of all available food items, macronutrients and body weight changes were monitored over 8 weeks. Main outcomes were long-term body-weight and daily change in relative caloric intake during the postoperative cafeteria period compared to the preoperative cafeteria. Results: During the first 12 days of postoperative cafeteria access, RYGB-rats exposed to OM+L had a higher mean caloric intake per day than RYGB rats exposed to OM alone (Δ10 kCal, P adj = 0.004), but this difference between the RYGB groups disappeared thereafter. Consequently, in the last 33 days of the postoperative cafeteria diet, the mean body weight of the RYGB+OM+L group was higher compared to RYGB+OM (Δ51 g, P adj < 0.001). RYGB rats, independently from the nutritional intervention, presented a progressive decrease in daily consumption of calories from fat and increased their daily energy intake mainly from non-sugar carbohydrates. No such differences were detected in sham-operated controls exposed to low- or high fat postoperative interventions. Conclusion: A progressive decrease in daily fat intake over time was observed after RYGB, independently from the nutritional intervention. This finding confirms that macronutrient preferences undergo progressive changes over time after RYGB and supports the role of ingestive adaptation and learning. Early postoperative exposure to high-fat food failed to accentuate fat avoidance and did not lead to superior weight loss in the long-term.

Burst-pause criterion derivation for drinkometer measurements of ingestive behavior.

The drinkometer is a promising device for the study of ingestive behavior of liquid meals in humans. It can be used to investigate behavior in different target populations. However, ingestive behavior has a great variability across study participants. Therefore, a new analytical approach is required for the extraction and analysis of drinkometer-derived data that could account for this variability. We developed an optimized protocol to predict an optimal burst-pause criterion (PC) for the extraction of PC-dependent microstructural parameters of ingestive behavior. These describe the microstructure of bursts, while PC-independent parameters describe the microstructure of sucks. Therefore, a PC is required to analyze separately two physiologically different parts of behavior. To accomplish this burst-pause criterion derivation (BPCD), a Gaussian Mixture Model (GMM) was built for estimation of two probability density functions (PDFs). These model the distribution of inter-suck intervals (ISIs) and inter-burst intervals (IBIs), respectively. The PC is defined at the intersection point of the two density functions. A Kaplan-Meier (KM) survival analysis was performed for post-hoc verification of the fit of the predicted optimal PC to the ISI distribution. In this protocol paper, we present a walkthrough of the data analysis of drinkometer-derived data for the measurement of microstructure of ingestive behavior based on previous results published by our group [1].•Standardization of the burst-pause criterion derivation for drinkometer measurements of ingestive behavior.•All codes are publicly available in a repository.•The method can be easily adapted to studies with larger sample size or more than one study stimulus.

Association between microstructure of ingestive behavior and body weight loss in patients one year after Roux-en-Y gastric bypass.

Roux-en-Y gastric bypass (RYGB) is one of the most effective procedures in the treatment of obesity. However, the predictive value of the microstructure of ingestion has not been widely investigated in this context. Here, we applied a recently developed drinkometer device to analyze the microstructure of ingestive behavior during a liquid meal in women and investigate whether it correlated with measures of weight loss after RYGB. Macro- and microstructural parameters of ingestive behavior of female patients (n = 24) one year after RYGB were measured in two different test sessions within a period of two weeks using the drinkometer. A Pearson correlation analysis was performed to compare the macro- and microstructural parameters of ingestive behavior with the percentage of total weight loss (%TWL), percentage excess BMI loss (%EBMIL), and body mass index (BMI) one year after RYGB, as well as age. A Bonferroni adjusted p < 0.003 was considered significant for the correlation analysis. For all other statistical tests, a p < 0.05 was considered significant. One year after surgery, a significant body weight loss was achieved in our study population (111.2 ± 15.6 kg vs 73.4 ± 11.7 kg; ***p < 0.001), with a mean%TWL of 33.8% (range: 20.4-48.6%). At the first test session,%TWL correlated with suck duration (r = 0.41, 0.05 > p > 0.003);%EBMIL correlated with both suck duration (r = 0.64, *p < 0.003) and inter-suck intervals (ISIs, r = -0.47, *p < 0.003), and, finally, BMI correlated with suck duration (r = 0.62, *p < 0.003) and ISIs (r = 0.48, *p < 0.003). However, at the second test session, no correlation was found between the body weight loss and the recorded ingestive parameters. Furthermore, no statistically significant difference was found in microstructural parameters of ingestive behavior between the two test sessions even though meal size decreased by 20% on the second visit (342.6.6 ± 167 kcal vs. 271.8 ± 142.8 kcal). A greater body weight loss of patients one year after surgery seems to be associated with longer suck duration and shorter ISIs, but only when the stimulus is tested for the first time by the study participants. This study contributes to the current knowledge about the ingestive behavior of bariatric patients one year after RYGB in terms of its association with the achieved weight loss. The use of the drinkometer device for the measurement of microstructure of ingestive behavior should be further expanded to different research questions and patient subgroups other than good responders. Its possible applications in clinical and behavioral research need to be included in the agenda of bariatric research.

How to Establish Benchmarks for Surgical Outcomes?: A Checklist Based on an International Expert Delphi Consensus.

OBJECTIVE: To define a standardized methodology for establishing benchmarks for relevant outcomes in surgery. SUMMARY BACKGROUND DATA: Benchmarking is an established tool to improve quality in industry and economics, and is emerging in assessing outcome values in surgery. Despite a recent 10-step approach to identify such benchmark values, a standardized and more widely agreed-on approach is still lacking. METHODS: A multinational web-based Delphi survey with a focus on methodological requirements for establishing benchmarks for surgical outcomes was performed. Participants were selected among internationally renowned specialists in abdominal, vascular, and thoracic surgery. Consensus was defined as ≥70% agreement and results were used to develop a checklist to establish benchmarks in surgery. RESULTS: Forty-one surgical opinion leaders from 19 countries and 5 continents were involved. Experts' response rates were 98% and 80% in rounds 1 and 2, respectively. Upon completion of the final Delphi round, consensus was successfully achieved for 26 of 36 items covering the following areas: center eligibility, validation of databases, patient cohort selection, procedure selection, duration of follow-up, statistical analysis, and publication requirements regarding center-specific outcomes. CONCLUSIONS: This multinational Delphi survey represents the first expert-led process for developing a standardized approach for establishing benchmarks for relevant outcome measures in surgery. The provided consensual checklist customizes the methodology of outcome reporting in surgery and thus improves reproducibility and comparability of data and should ultimately serve to improve quality of care.

Online survey on factors influencing patients' motivation to undergo bariatric surgery.

Given the worldwide increasing prevalence of severe obesity and considering the amount of scientific evidence demonstrating the beneficial effects of bariatric surgery (BS), it is surprising that only a fraction of patients with obesity undergo BS. We therefore conducted an anonymized online survey among individuals with a history of BS to understand factors influencing the deciding process leading to BS. Respondents were recruited on a voluntary basis from obesity-related social media groups between April and June 2020. The self-designed, non-validated questionnaire consisted of 20 questions and was open to any participants with a history of BS. Of 851 participants who started the survey, 665 completed the questionnaire (completion rate of 78.1%). Five years after BS, still 70% of the survey-participants were very satisfied or satisfied with the surgical result. However, the majority (73.3%) would have undergone BS earlier. The main motivation to choose BS was related to health status or quality of life. Important characteristics for a bariatric surgeon to obtain patients' trust are "taking time and listen" (74.7%), empathy (64%) and sympathy (56%). Post-operative satisfaction with the surgical outcome was high and long-lasting in this large cohort of BS patients. However, most participants would retrospectively have undergone BS earlier. The main reason to choose BS as treatment for their obesity were impaired physical health or reduced quality of life. Nearby location to patients' residence and availability of surgeons with empathy were decisive motives for bariatric centre selection.