SAGES video acquisition framework-analysis of available OR recording technologies by the SAGES AI task force.

BACKGROUND: Surgical video recording provides the opportunity to acquire intraoperative data that can subsequently be used for a variety of quality improvement, research, and educational applications. Various recording devices are available for standard operating room camera systems. Some allow for collateral data acquisition including activities of the OR staff, kinematic measurements (motion of surgical instruments), and recording of the endoscopic video streams. Additional analysis through computer vision (CV), which allows software to understand and perform predictive tasks on images, can allow for automatic phase segmentation, instrument tracking, and derivative performance-geared metrics. With this survey, we summarize available surgical video acquisition technologies and associated performance analysis platforms. METHODS: In an effort promoted by the SAGES Artificial Intelligence Task Force, we surveyed the available video recording technology companies. Of thirteen companies approached, nine were interviewed, each over an hour-long video conference. A standard set of 17 questions was administered. Questions spanned from data acquisition capacity, quality, and synchronization of video with other data, availability of analytic tools, privacy, and access. RESULTS: Most platforms (89%) store video in full-HD (1080p) resolution at a frame rate of 30 fps. Most (67%) of available platforms store data in a Cloud-based databank as opposed to institutional hard drives. CV powered analysis is featured in some platforms: phase segmentation in 44% platforms, out of body blurring or tool tracking in 33%, and suture time in 11%. Kinematic data are provided by 22% and perfusion imaging in one device. CONCLUSION: Video acquisition platforms on the market allow for in depth performance analysis through manual and automated review. Most of these devices will be integrated in upcoming robotic surgical platforms. Platform analytic supplementation, including CV, may allow for more refined performance analysis to surgeons and trainees. Most current AI features are related to phase segmentation, instrument tracking, and video blurring.

SAGES consensus recommendations on surgical video data use, structure, and exploration (for research in artificial intelligence, clinical quality improvement, and surgical education).

BACKGROUND: Surgery generates a vast amount of data from each procedure. Particularly video data provides significant value for surgical research, clinical outcome assessment, quality control, and education. The data lifecycle is influenced by various factors, including data structure, acquisition, storage, and sharing; data use and exploration, and finally data governance, which encompasses all ethical and legal regulations associated with the data. There is a universal need among stakeholders in surgical data science to establish standardized frameworks that address all aspects of this lifecycle to ensure data quality and purpose. METHODS: Working groups were formed, among 48 representatives from academia and industry, including clinicians, computer scientists and industry representatives. These working groups focused on: Data Use, Data Structure, Data Exploration, and Data Governance. After working group and panel discussions, a modified Delphi process was conducted. RESULTS: The resulting Delphi consensus provides conceptualized and structured recommendations for each domain related to surgical video data. We identified the key stakeholders within the data lifecycle and formulated comprehensive, easily understandable, and widely applicable guidelines for data utilization. Standardization of data structure should encompass format and quality, data sources, documentation, metadata, and account for biases within the data. To foster scientific data exploration, datasets should reflect diversity and remain adaptable to future applications. Data governance must be transparent to all stakeholders, addressing legal and ethical considerations surrounding the data. CONCLUSION: This consensus presents essential recommendations around the generation of standardized and diverse surgical video databanks, accounting for multiple stakeholders involved in data generation and use throughout its lifecycle. Following the SAGES annotation framework, we lay the foundation for standardization of data use, structure, and exploration. A detailed exploration of requirements for adequate data governance will follow.

Bariatric Surgery and Cardiovascular Outcomes in Patients With Obesity and Cardiovascular Disease:: A Population-Based Retrospective Cohort Study.

BACKGROUND: Bariatric surgery has been shown to significantly reduce cardiovascular risk factors. However, whether surgery can reduce major adverse cardiovascular events (MACE), especially in patients with established cardiovascular disease, remains poorly understood. The present study aims to determine the association between bariatric surgery and MACE among patients with cardiovascular disease and severe obesity. METHODS: This was a propensity score-matched cohort study using province-wide multiple-linked administrative databases in Ontario, Canada. Patients with previous ischemic heart disease or heart failure who received bariatric surgery were matched on age, sex, heart failure history, and a propensity score to similar controls from a primary care medical record database in a 1:1 ratio. The primary outcome was the incidence of extended MACE (first occurrence of all-cause mortality, myocardial infarction, coronary revascularization, cerebrovascular events, and heart failure hospitalization). Secondary outcome included 3-component MACE (myocardial infarction, ischemic stroke, and all-cause mortality). Outcomes were evaluated through a combination of matching via propensity score and subsequent multivariable adjustment. RESULTS: A total of 2638 patients (n=1319 in each group) were included, with a median follow-up time of 4.6 years. The primary outcome occurred in 11.5% (151/1319) of the surgery group and 19.6% (259/1319) of the controls (adjusted hazard ratio [HR], 0.58 [95% CI, 0.48-0.71]; P<0.001). The association was notable for those with heart failure (HR, 0.44 [95% CI, 0.31-0.62]; P<0.001; absolute risk difference, 19.3% [95% CI, 12.0%-26.7%]) and in those with ischemic heart disease (HR, 0.60 [95% CI, 0.48-0.74]; P<0.001; absolute risk difference, 7.5% [95% CI, 4.7%-10.5%]). Surgery was also associated with a lower incidence of the secondary outcome (HR, 0.66 [95% CI, 0.52-0.84]; P=0.001) and cardiovascular mortality (HR, 0.35 [95% CI, 0.15-0.80]; P=0.001). CONCLUSIONS: Bariatric surgery was associated with a lower incidence of MACE in patients with cardiovascular disease and obesity. These findings require confirmation by a large-scale randomized trial.

Outcomes of bariatric surgery in elderly patients: a registry-based cohort study with 3-year follow-up.

BACKGROUND: Elderly patients undergo bariatric surgery less frequently than younger patients. Short- and medium-term outcomes after bariatric surgery in the elderly population remain largely unknown. The objective of the present retrospective, registry-based cohort study was to compare short- and medium-term outcomes between patients <65 and ≥65 years undergoing bariatric surgery, hypothesizing similar outcomes between groups. METHODS: In this retrospective, registry-based cohort study, the Ontario Bariatric Registry was used to compare data of patients <65 and ≥65 years who underwent Roux-en-Y gastric bypass and sleeve gastrectomy between January 2010 and August 2019 in all accredited bariatric centers of excellence in Ontario, Canada. Primary outcomes were overall postoperative complications. Secondary outcomes included early (<30 days) complications, readmissions, reoperations, mortality, weight loss and comorbidities improvement at 1 and 3 year after surgery. RESULTS: Data of 22,981 patients <65 and 532 patients ≥65 years were analyzed. Overall postoperative complications were similar between patients <65 and ≥65 years (3388/22,981 [14.7%] vs. 73/532 [13.7%], p = 0.537). Early (<30 days) postoperative complications, readmissions, reoperations, and mortality rates were also similar between groups. Both groups had significant weight loss and comorbidities improvement at 1- and 3-year follow-up. Patients <65 years had superior weight loss (+3.5%, 95% CI: 1.6-5.4, p < 0.001) and higher rates of remission for diabetes mellitus (63.8% vs. 39.3%, p < 0.001), hypertension (37.9% vs. 14.5%, p < 0.001), dyslipidemia (28.2% vs. 9.5%, p < 0.001) and gastroesophageal reflux (65.1% vs. 24.0 %, p < 0.001) compared to patients ≥65 years at 3 year. CONCLUSIONS: Patients <65 and ≥65 years had similar perioperative morbidity and mortality after bariatric surgery. Even though patients <65 years had overall better medium-term outcomes, bariatric surgery is safe and yields significant weight loss and comorbidities improvement in patients ≥65 years.

Bariatric Center Designation and Outcomes Following Repeat Abdominal Surgery in Bariatric Patients.

INTRODUCTION: Repeat abdominal surgery in the bariatric surgery patient population may be challenging for non-bariatric-accredited institutions. The impact of regionalized bariatric care on clinical outcomes for bariatric surgery patients requiring repeat abdominal surgery is currently unknown. This study aims to investigate the association between bariatric center designation and clinical outcomes following hepatobiliary, hernia, and upper and lower gastrointestinal operations among patients with prior bariatric surgery. METHODS: This is a cohort study of a large sample of Ontario residents who underwent primary bariatric surgery between 2010 and 2017. A comprehensive list of eligible abdominal operations was captured using administrative data. The primary outcome was 30-d complications. Secondary outcomes included 30-d mortality, readmission, and length of stay. RESULTS: Among the 3301 study patients, 1305 (40%) received their first abdominal reoperation following bariatric surgery at a designated bariatric center. Nonbariatric center designation was not associated with significantly higher rates of 30-d complications (5.73% versus 5.72%), mortality (0.80% versus 0.77%), readmissions (1.11% versus 1.85%), or median postoperative length of stay (4 versus 4 d). After grouping the category of reoperations, upper gastrointestinal (odds ratio [OR] 0.66, confidence interval [CI] 0.39-1.11) and abdominal wall hernia surgery (OR 0.52, CI 0.27-0.99) showed a lower adjusted OR for complications among bariatric centers. CONCLUSIONS: Our study demonstrates that after adjustment for case-mix and patient characteristics, bariatric surgery patients undergoing repeat abdominal surgery at nonbariatric centers is not associated with higher proportion of complications or mortality. Complex hernia surgery may be considered the most appropriate for referral.

What patient factors influence bariatric surgery outcomes? A multiple regression analysis of Ontario Bariatric Registry data.

BACKGROUND: As bariatric surgery evolves and gains popularity, statistical analysis of its outcomes could improve the process of decision-making and risk assessment. This study aimed to evaluate the influence of age and other factors on bariatric surgery outcomes in order to improve patient selection and outcomes. METHODS: We analyzed data from the Ontario Bariatric Registry to evaluate the influence of age and 10 other factors on early (< 90 d) and 1-year surgical outcomes among patients aged 18 years or older who underwent laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) between January 2010 and May 2013. Early outcomes included composite adverse events and readmission. The 1-year outcomes included percent excess body weight loss (%EBWL), and remission of diabetes mellitus and hypertension. We performed multiple regression analysis to identify independent variables that influenced these outcomes. RESULTS: We identified 3166 patients (2655 women [83.9%] and 511 men [16.1%], mean age 44.8 yr, mean body mass index [BMI] 48.4) who underwent LRYGB (2839 [89.7%]) or LSG (327 [10.3%]) over the study period and completed their 1-year follow-up. Preoperative American Society of Anesthesiologists (ASA) score and history of angina were independent variables that influenced the composite adverse event outcome. Obstructive sleep apnea was the only factor that influenced early readmission. The independent factors that influenced %EBWL were age, type of surgery, BMI and baseline glycosylated hemoglobin (HbA1c) level: age was found to influence hypertension remission, and HbA1c level and obstructive sleep apnea were found to influence diabetes remission. CONCLUSION: Complications after bariatric surgery can be predicted by preoperative ASA score and history of angina; patient age was not related to an increase in postoperative complications. These factors could help both surgeon and patient make appropriate surgical decisions.

Laparoscopic Sleeve Gastrectomy Versus Laparoscopic Roux-en-Y Gastric Bypass: A Systematic Review and Meta-analysis of Weight Loss, Comorbidities, and Biochemical Outcomes From Randomized Controlled Trials.

OBJECTIVE: The aim of this study was to compare weight loss, obesity-related comorbidities, and biochemical outcomes of LSG versus LRYGB through a meta-analysis of randomized controlled trials (RCTs). SUMMARY OF BACKGROUND DATA: LSG and LRYGB are the 2 most commonly performed bariatric surgeries for the treatment of obesity. The comparative outcomes of the 2 surgeries is a topic of ongoing debate and medium-term outcomes remain uncertain. METHODS: A search for RCTs comparing LRYGB versus LSG was conducted. Pooled outcomes between 2 procedures were compared using pairwise random-effects meta-analysis at 1, 3, and 5-year follow-up time points. Grading of recommendations, assessment, development, and evaluation was used to assess certainty of evidence. RESULTS: Thirty-three studies involving 2475 patients were included. LRYGB resulted in greater loss of body mass index compared to LSG at 1 year [mean difference -1.25 kg/m2, 95% confidence interval (CI) -2.01 to -0.49, P = 0.001; moderate certainty of evidence] which persisted at 3 years, but there was insufficient evidence at 5 years. Resolution of dyslipidemia was higher for LRYGB than LSG at 1 year (risk ratio 0.58, 95% CI 0.46-0.73, P < 0.001; moderate certainty of evidence) and 5 years (risk ratio 0.68, 95%CI 0.46-0.99, P = 0.04; low certainty of evidence). There was no difference between LRYGB and LSG for remission of type 2 diabetes, hypertension, and hemoglobin A1c, fasting insulin, homeostatic model assessment of insulin resistance, high-density lipoprotein, and the rate of 30-day major and minor complications. CONCLUSIONS: There are insufficient data from RCTs to draw any conclusions regarding the long-term comparative effectiveness beyond 3 years between LRYGB and LSG.

Comparison of single- versus double-anastomosis duodenal switch: a single-center experience with 2-year follow-up.

BACKGROUND: Single-anastomosis duodenal switch (SADS) has emerged in recent years as an alternative to the standard double-anastomosis duodenal switch (DADS). The objective of this study was to compare short- and medium-term outcomes between SADS and DADS. METHODS: Data collected in the Ontario Bariatric Registry between 2010 and 2019 were used for this retrospective study to determine outcomes of patients undergoing primary laparoscopic SADS versus DADS at a Canadian tertiary hospital and bariatric center of excellence. The primary outcome was weight loss at 1 and 2 years after surgery. Short-term secondary outcomes included operative times, intra- and early postoperative complications, hospital length of stay (LOS), and 30-day readmissions. Medium-term secondary outcomes included late postoperative complications as well as nutritional deficiencies and persistent diarrhea at 1 and 2 years after surgery. Subgroup analyses were performed to compare patients undergoing one- and two-stage procedures. RESULTS: Data of 107 patients who underwent SADS (n = 25) or DADS (n = 82) were included in the study. Follow-up data were available for 59/107 (55.1%) patients at 1 year and 47/107 (43.9%) at 2 years after surgery. Patients in the SADS and DADS groups had similar %TBWL at 1 year (23.6 versus 26.2, P = 0.617) and 2 years (24.8 versus 30.2, P = 0.116) after surgery. Short- and medium-term outcomes were similar between groups. There was no difference between patients undergoing one- versus two-stage procedures. CONCLUSION: This study showed that patients undergoing SADS and DADS had similar weight loss at 1 and 2 years. Early and late postoperative morbidity, operative times, early readmissions, and LOS were also similar between groups. Further studies with longer follow-up are required to confirm these results.

From telementorship to automation.

The effective integration of robotic technology and surgical tools has played a vital role in advancing surgical care by enabling telepresence in surgery to provide mentorship and surgical care across long distances in the absence of surgeons. This article describes our experiences with advancing surgical education and innovation through telementoring community surgeons, establishing the world's first telerobotic surgical service, and the integration of Artificial Intelligence and robotics to provide remote surgical care and training.

Marginal ulceration following Roux-en-Y gastric bypass: risk factors for ulcer development, recurrence and need for revisional surgery.

BACKGROUND: Marginal ulcer formation is a known complication following RYGB. While most respond to medical therapy, many patients have recurrent or chronic MU. Although non-steroidal anti-inflammatory drug (NSAID) use, smoking and Helicobacter pylori infection are known risk factors of MU, little is known about what increases the likelihood of developing recalcitrant ulcers. The objective of this study is to identify risk factors for marginal ulcer (MU) formation, including recalcitrant ulcers requiring surgical revision, and to define the incidence and outcomes of revisional surgery. METHODS: All patients who underwent RYGB between 2011 and 2017 at a high-volume academic center were included. Patients with a postoperative diagnosis of MU were identified from the institution's bariatric database. Patient characteristics, operative data and surgical outcomes were analyzed using data collected in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program and the Ontario Bariatric Registry. RESULTS: A total of 2830 RYGB were performed during the study period. The incidence of MU was 6.9% with 1% of patients requiring revisional surgery for a recalcitrant ulcer. Patients with a history of smoking (HR 5.03), immunosuppression (HR 4.60) and preoperative NSAID use (HR 3.11) were significantly more likely to develop a MU requiring surgical revision. Patients undergoing revision reported resolution of their symptoms in only 36% of cases with 57% developing a recurrent ulcer. CONCLUSION: Patients with a history of smoking and use of immunosuppressive medication were at significantly higher risk of developing MU that failed medical therapy. Additional evidence is needed to inform perioperative management of bariatric patients.

Access to bariatric surgery among older patients in a publicly funded regionalized care system.

BACKGROUND: Bariatric surgery in older patients is safe and effective. Current guidelines do not endorse age limits for surgery; however, older patients may encounter difficulties with access given perceived risks. This study compares the adjusted probability of failing to receive bariatric surgery between older (≥ 60 years) and younger (< 60 years) patients referred to a publicly funded program. STUDY DESIGN: This is a retrospective cohort study of adult patients referred to a bariatric surgery program in Ontario from 2010-2016. Ontario health administrative databases and the Ontario Bariatric Registry were used for the analysis. The primary outcome was receipt of bariatric surgery within 3 years of referral. A multivariable logistic regression analysis was performed to determine the adjusted effect of older age (≥ 60 years) on the probability of not receiving surgery. Sensitivity analysis was performed using only healthy patients. RESULTS: Among 19,510 patients referred to the program, 1,795 patients (9.2%) were ≥ 60 years old, of which 60% received bariatric surgery within 3 years compared to 90% in younger patients. The odds older patients do not receive surgery after adjustment were significantly higher compared to younger patients (OR 1.69 [1.52-1.88], P < .001). This effect persists even among a subgroup of older patients with a Charlson Comorbidity Index = 0 (OR 1.78 [1.56-2.04], P < .001). CONCLUSIONS: Age alone, rather than comorbidities had a more significant effect on the access to bariatric surgery in older patients. Given the demonstrated benefits of bariatric surgery in older populations, ensuring equity in access to bariatric surgery should be encouraged. Future research is required to explore the underlying reasons why older patients who could benefit from bariatric surgery may not have the opportunity.

Association Between Bariatric Surgery and All-Cause Mortality: A Population-Based Matched Cohort Study in a Universal Health Care System.

BACKGROUND: Mortality after bariatric surgery has been previously studied, but cohort selection bias, completeness of follow-up, and collection of confounders have limited the inference of results. OBJECTIVE: To determine the association between bariatric surgery and all-cause mortality. DESIGN: Population-based matched cohort study. SETTING: Ontario, Canada. PARTICIPANTS: 13 679 patients who underwent bariatric surgery from January 2010 to December 2016 and 13 679 matched nonsurgical patients. INTERVENTION: Bariatric surgery. MEASUREMENTS: The primary outcome was all-cause mortality, with cause-specific mortality as the secondary outcome. Patients were matched according to age, sex, body mass index, and diabetes duration. RESULTS: 13 679 patients who underwent bariatric surgery were matched to 13 679 nonsurgical patients. After a median follow-up of 4.9 years, the overall mortality rate was 1.4% (n = 197) in the surgery group and 2.5% (n = 340) in the nonsurgery group, with a lower adjusted hazard ratio (HR) of overall all-cause mortality (HR, 0.68 [95% CI, 0.57 to 0.81]). Patients aged 55 years or older had an absolute risk reduction of 3.3% (CI, 2.3% to 4.3%), with a lower HR of mortality in the surgery group (HR, 0.53 [CI, 0.41 to 0.69]). Observed relative effects were similar across sex; however, the observed association in absolute terms was greater in men. Surgery also was associated with lower cardiovascular mortality (HR, 0.53 [CI, 0.34 to 0.84]) and lower cancer mortality (HR, 0.54 [CI, 0.36 to 0.80]). LIMITATION: The observational design limits causal inference. CONCLUSION: Bariatric surgery was associated with substantially lower all-cause, cardiovascular, and cancer mortality. The lowered observed mortality of surgery was significant across most subgroups. The largest absolute effects were for men and patients aged 55 years or older. PRIMARY FUNDING SOURCE: Ontario Bariatric Network.

Patients eligible and referred for bariatric surgery in southeastern Ontario: Retrospective cohort study.

OBJECTIVE: To evaluate the proportion of eligible individuals, within one health region in Ontario, who were referred for publicly funded medical and surgical weight-loss interventions (MSWLI). DESIGN: A retrospective cohort study that used primary care data from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) and referral data from the Ontario Bariatric Network (OBN). SETTING: Primary care practices within southeastern Ontario that contribute data to CPCSSN. PARTICIPANTS: Patients with class II (body mass index [BMI] 35.0 to 39.9 kg/m2) or III (BMI ≥ 40 kg/m2) obesity who were eligible for referral to the OBN for MSWLI. MAIN OUTCOME MEASURES: Primary care data about patients within the CPCSSN database were linked to referral records within the OBN database using 3 indirect identifiers to determine the proportion of patients with class II and III obesity who were referred to the OBN for MSWLI. An adjusted multivariate logistic regression model was used to determine the most significant predictors of referral. RESULTS: Of the 87 276 patients within one health region in Ontario, 15 526 (17.8%) patients had class II or III obesity and were eligible for referral for MSWLI. Only 966 out of those 15 526 (6.2%) patients were actually referred for MSWLI. In the multivariate regression analysis, BMI had the strongest association with referral in terms of adjusted odds ratio (AOR), varying from 2.50 (95% CI 2.04 to 3.06) for a BMI of 40.0 to 44.9 kg/m2, to 5.15 (95% CI 4.21 to 6.30) for a BMI of 50.0 kg/m2 or greater. Referral was more likely for female than male patients (AOR = 2.18; 95% CI 1.86 to 2.57), those living rurally than for urban dwellers (AOR = 1.39; 95% CI 1.20 to 1.60), and those aged 30 to 39 (AOR = 1.61; 95% CI 1.24 to 2.09) and 40 to 49 (AOR = 1.53; 95% CI 1.18 to 1.98) compared with other age groups. CONCLUSION: Within one health region in Ontario, the referral rate of patients with class II and III obesity for MSWLI was low. Our findings highlight the need for further research to understand and address the barriers to referral of patients with class II and III obesity for MSWLI.

The hidden cost of an extensive preoperative work-up: predictors of attrition after referral for bariatric surgery in a universal healthcare system.

BACKGROUND: Bariatric surgery is in high demand and patients generally undergo an extensive work-up process to maximize the success of surgery, especially in universal healthcare systems. Although valuable, this work-up process can lead to attrition before surgery. Therefore, we aim to assess patient and health system factors associated with attrition after bariatric surgery referral in a universal healthcare system. METHODS: This was a population-based study of all patients aged ≥ 18 referred for bariatric surgery in Ontario, Canada from 2009 to 2015. Primary outcome was patients who dropped out of bariatric surgery after referral. Predictors of attrition after referral included patient demographics, clinical, institutional, and socioeconomic variables. Odds ratios and 95% CIs were estimated by multilevel logistic regression models. RESULTS: From 17,703 patients that were referred for bariatric surgery, 4122 patients dropped after the initial referral. Male patients, increasing age, and longer wait times for surgery were significantly (P < 0.0001) associated with higher odds of attrition. Additionally, smoker status, immigration status, unemployment, and disability were significant factors (P < 0.0001) predicting attrition. Patients who lived in lowest income quintile neighborhoods, when compared to those from the richest neighborhoods, had significantly higher odds of attrition (P = 0.02). Sleep apnea was associated with lower odds of attrition while diabetes and heart failure both with higher odds of attrition. CONCLUSION: Even in a universal healthcare system, there are various factors that could lead to increased odds of attrition before bariatric surgery. Clear disparities exist for certain marginalized populations. Further studies are warranted to ensure equitable utilization of bariatric surgery for all patients.

The effect of surrogate procedure volume on bariatric surgery outcomes: do common laparoscopic general surgery procedures matter?

BACKGROUND: A growing body of evidence shows that experience and acquired skills from surrogate surgical procedures may be transferrable to a specific index operation. It is unclear whether this applies to bariatric surgery. This study aims to determine whether there is a surrogate volume effect of common laparoscopic general surgery procedures on all-cause bariatric surgical morbidity. METHODS: This was a population-based study of all patients aged ≥ 18 who received a bariatric procedure in Ontario from 2008 to 2015. The main outcome of interest was all-cause morbidity during the index admission. All-cause morbidity included any documented complication which extended length of stay by 24 h or required reoperation. Bariatric cases included laparoscopic Roux-en-Y gastric bypass, sleeve gastrectomy, and biliopancreatic diversion with duodenal switch. Non-bariatric cases included three common laparoscopic general surgery procedures. RESULTS: 13,836 bariatric procedures were performed by 29 surgeons at nine centers of excellence. A reduction in all-cause morbidity was seen when bariatric surgeons exceeded 75 cases annually (OR 0.82, 95% CI 0.69-0.98, P = 0.023), with further reduction in increasing bariatric volume. However, the volume of non-bariatric surgeries did not significantly affect bariatric all-cause morbidity rates amongst bariatric surgeons, even when exceeding 100 cases (OR 0.84, 95% CI 0.61-1.12, P = 0.222). CONCLUSIONS: The present study suggests that experience and skills acquired in performing non-bariatric laparoscopic general surgery does not appear to affect all-cause morbidity in bariatric surgery. Therefore, only a surgeon's bariatric procedure volume should considered be a quality marker for outcomes after bariatric surgery.

Complete Resolution of Nonalcoholic Fatty Liver Disease After Bariatric Surgery: A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Bariatric surgery has been reported to lead to complete resolution of nonalcoholic fatty liver disease (NAFLD) following the sustained weight loss induced in obese patients. We performed a systematic review and meta-analysis to evaluate the effects of bariatric surgery on NAFLD in obese patients. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and Web of Science databases through May 2018 for studies that compared liver biopsy results before and after bariatric surgery in obese patients. Primary outcomes were biopsy-confirmed resolution of NAFLD and NAFLD activity score. Secondary outcomes were worsening of NAFLD after surgery and liver volume. The Grading of Recommendations, Assessment, Development, and Evidence approach was conducted to assess overall quality of evidence. RESULTS: We analyzed data from 32 cohort studies comprising 3093 biopsy specimens. Bariatric surgery resulted in a biopsy-confirmed resolution of steatosis in 66% of patients (95% CI, 56%-75%), inflammation in 50% (95% CI, 35%-64%), ballooning degeneration in 76% (95% CI, 64%-86%), and fibrosis in 40% (95% CI, 29%-51%). Patients' mean NAFLD activity score was reduced significantly after bariatric surgery (mean difference, 2.39; 95% CI, 1.58-3.20; P < .001). However, bariatric surgery resulted in new or worsening features of NAFLD, such as fibrosis, in 12% of patients (95% CI, 5%-20%). The overall Grading of Recommendations, Assessment, Development, and Evidence quality of evidence was very low. CONCLUSIONS: Through this systematic review and meta-analysis, we found that bariatric surgery leads to complete resolution of NAFLD in obese patients. However, some patients develop new or worsened features of NAFLD. Randomized controlled trials are needed to further examine the therapeutic benefits of bariatric surgery for patients with NAFLD.

The impact of bariatric surgery on urinary incontinence: a systematic review and meta-analysis.

OBJECTIVES: To systematically review and meta-analyse the impact of bariatric surgery on obese patients with urinary incontinence (UI). METHODS: A search of the Medical Literature Analysis and Retrieval System Online (MEDLINE), the Excerpta Medica dataBASE (EMBASE), Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), and PubMed to June 2018 was performed using methods pre-published on the International Prospective Register of Systematic Reviews (PROSPERO). Reporting followed the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Studies comparing UI status in obese patients before and after bariatric surgery were included. Primary outcomes were the improvement or complete resolution of any UI, stress UI (SUI), and urgency UI (UUI). Secondary outcomes were validated UI questionnaire scores. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach assessed overall quality of evidence. RESULTS: In all, 33 cohort studies (2910 patients) were included (median follow-up 12 months). Bariatric surgery resulted in improvement or resolution of any UI in 56% (95% confidence interval [CI] 48-63%), SUI in 47% (95% CI 34-60%), and UUI in 53% (95% CI 32-73%) of patients. Moreover, bariatric surgery significantly decreased (P < 0.001) questionnaire scores such as: the Urogenital Distress Inventory by 13.4 points (95% CI 7.2-19.6), International Consultation on Incontinence Questionnaire by 4.0 points (95% CI 2.3-5.7), and Incontinence Impact Questionnaire by 5.3 points (95% CI 3.9-6.6). However, worsening or new onset of UI was present in 3% of patients. The quality of evidence was very low for all outcomes. CONCLUSION: Half of obese patients report improvement or resolution of UI after bariatric surgery, but overall the quality of evidence is very low. Comparative studies examining the benefits of bariatric surgery in obese patients with UI are warranted.

The value of surgical experience: excess costs associated with the Roux-en-Y gastric bypass learning curve.

BACKGROUND: Gastric bypass has a steep learning curve that is associated with increased adverse outcomes and these adverse outcomes are associated with increases in cost. This study sought to quantify the effect of cumulative procedure volume on inpatient cost and characterize the excess cost associated with a surgeon's learning curve. METHODS: This was a retrospective study of 29 high-volume surgeons during the first 6 years of performing gastric bypass in a regionalized center of excellence system. Cumulative volume was determined using the procedure date and analyzed in blocks of 25 cases. The main outcomes of interest were inpatient cost for the initial hospital stay in 2014 Canadian dollars as well as prolonged length of stay (≥ 3 days). RESULTS: Overall, 11,684 cases were identified from April 2009 to March 2015. After a surgeon's 50th case, the adjusted inpatient cost decreased by $2775 (95% CI $- 4352 to $- 1204 p = 0.001) compared to the first 25 cases. Cost savings were maintained through a surgeon's 400th case. The average cost savings after the 50th case was $2082 (95% CI $- 3194 to $- 962 p < 0.001) and the excess cost attributable to the first 50 cases was $104,077 (95% CI 48,104 to 159,682) per surgeon. Surgeon experience was also associated with a decrease odds of prolonged length of stay. CONCLUSIONS: This study demonstrated the influence of surgeon experience on improved cost efficiencies. We also characterized that the average excess cost per surgeon of implementing gastric bypass was approximately $104,000. This is relevant to future health system planning as well as providing an economic incentive for impactful training interventions.

Mastery in Bariatric Surgery: The Long-term Surgeon Learning Curve of Roux-en-Y Gastric Bypass.

OBJECTIVE: To determine the effect of cumulative volume on all-cause morbidity and operative time. BACKGROUND: Gastric bypass is an important public health procedure, but it is difficult to master with little data about how surgeon cumulative volume affects outcomes longitudinally. METHODS: This was a longitudinal study of 29 surgeons during the first 6 years of performing bariatric surgery in a high-volume, regionalized center of excellence system. Cumulative volume was determined using date and time of the procedure. Cumulative volume was analyzed in blocks of 75 cases. The main outcome of interest was all-cause morbidity during the index admission and the secondary outcome was operative time. RESULTS: Overall, 11,684 gastric bypasses were performed by 29 surgeons at 9 centers of excellence. The overall morbidity rate was 10.1% and short-term outcomes were related significantly to cumulative volume. Perioperative risk plateaued after approximately 500 cases and was lowest for surgeons who had completed more than 600 cases (odds ratio 0.53 95% confidence interval 0.26-0.96 P = 0.04) compared to the first 75 cases. Operative time also stabilized after approximately 500 cases, with an operative time 44.7 minutes faster than surgeons in their first 75 cases (95% confidence interval 37.0-52.4 min P < 0.001). CONCLUSIONS: The present study demonstrated the clear, substantial influence of surgeon cumulative volume on improved perioperative outcomes and operative time. This finding emphasizes role of the individual surgeon in perioperative outcomes and that the true learning curve needed to master a complex surgical procedure such as gastric bypass is longer than previously thought, in this case requiring approximately 500 cases to plateau.

The impact of bariatric surgery on insulin-treated type 2 diabetes patients.

INTRODUCTION: Bariatric surgery has been shown to lead to significant improvement in glucose homeostasis, resulting in greater rates of type 2 diabetes mellitus (T2DM) remission. While there is substantial evidence of the benefits of bariatric/metabolic surgery in obese diabetic patients on oral therapy (O-T2D), more evidence is necessary in the case of insulin-treated type 2 diabetes (I-T2D) patients and the selection of surgical procedure. METHODS: Analysis of the Ontario Bariatric Registry data was performed, comparing outcomes of Roux-en-Y-gastric bypass (RYGB) and sleeve gastrectomy (SG) on insulin-treated versus non-insulin-treated T2DM patients. We compared weight loss, medication use and remission rates during a 3-year follow up. RESULTS: A total of 3668 diabetic Bariatric Registry patients underwent surgery from Jan 2010 to Feb 2017, across 7 Bariatric Centers of Excellence in Ontario. Of these 2872 were O-T2D and 1187 were I-T2D. Weight loss was similar between the two groups at 3 years; with mean %WL of 30.1% for the insulin group vs. 28.3% non-insulin (p = 0.0673). At 3 years, 11.3% of the non-insulin and 59.6% of the insulin-dependent group were using anti-diabetic medication (p < 0.0001). Among insulin-dependent patients, RYGB showed greater reduction in insulin use with 26.5 and 40% compared to SG at 3 years. O-T2D patients experienced more complete diabetes remission, with 66.5 vs. 18.5% (p < 0.0001) at 3 years. Complete remission for I-T2D patients was higher in the RYGB group than SG (p < 0.0001) at years 1 and 2 (8.5 vs. 5.4% and 24.4 vs. 21.1%). The same trend was found regardless of insulin use; complete remission higher for RYGB at 1 and 2 years [50.7 vs. 39.8% (p < 0.0001), and 54.6 vs. 49.1% (p < 0.0001)]. CONCLUSION: While both RYGB and SG procedures provide effective treatment for I-T2D patients in terms of weight loss and diabetes, incidence of complete remission for insulin-dependent patients is higher with RYGB in earlier years.