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.

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.

Bariatric Surgery in Patients with a History of Nephrolithiasis: 24-h Urine Profiles and Radiographic Changes After Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy.

BACKGROUND: To evaluate the differences in 24-h urine profiles, radiographic imaging, and stone events post-Roux-en-Y gastric bypass versus sleeve gastrectomy in patients with a history of nephrolithiasis. METHODS: A retrospective review was conducted on 102 patients with a history of nephrolithiasis who then underwent bariatric surgery at our tertiary academic center. Computed tomography imaging and 24-h urine profile values were performed pre-operatively and at 1-year follow-up. RESULTS: A total of 60 patients underwent Roux-en-Y gastric bypass and 42 had sleeve gastrectomy. The Roux-en-Y gastric bypass group had significant increases in oxalate and decreases in citrate (p = 0.009 and 0.003, respectively), while the sleeve gastrectomy group had decreases in oxalate and stable citrate (p = 0.013 and 0.906, respectively). Roux-en-Y gastric bypass was the only significant predictor of post-operative hyperoxaluria (OR 7.1 [95% CI 2.3-21.3], p = 0.001). Radiographically, 38.3% of the Roux-en-Y gastric bypass group and 26.2% of the sleeve gastrectomy group had an increase in stone burden, and post-operative stone procedure rate was 10.0% and 7.1%, respectively. CONCLUSIONS: At 1-year post-bariatric surgery, patients who underwent Roux-en-Y gastric bypass had exacerbated lithogenic urinary profiles, while those in sleeve gastrectomy patients improved. Although not statistically significant, stone burden increase and stone procedure rate were higher post-Roux-en-Y gastric bypass and will likely worsen at a longer follow-up due to the group's lithogenic 24-h urine profiles. These findings support pre-bariatric counseling and urinary monitoring in patients with a history of kidney stones who undergo RYGB, with a multi-disciplinary approach between urologists and general surgeons.

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.

A Longitudinal Analysis of Wait Times for Bariatric Surgery in a Publicly Funded, Regionalized Bariatric Care System.

BACKGROUND: Bariatric surgery is proven to be the most effective strategy for management of obesity and its related comorbidities. However, in Canada, patients awaiting bariatric surgery can be subjected to prolonged wait times, thereby subjecting them to increased morbidity and mortality, as well as decreased psychosocial well-being. OBJECTIVE: To assess the factors associated with prolonged wait times for bariatric surgery within a publicly funded, provincial bariatric network. METHODS: This was a retrospective population-based study of all patients aged > 18 years who were referred for bariatric surgery from April 2009 to May 2015 using linked administrative databases to capture patient demographic data, socioeconomic variables, healthcare utilization, and institutional factors. The main outcome of interest was a wait time greater than 18 months. Multivariate logistic regression modeling was used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: A total of 18,854 patients underwent bariatric surgery from April 2009 to December 2016, of which 2407 patients experienced wait times of > 18 months. On average, yearly wait times have increased for patients receiving surgery with wait times of 10.98 months (SD 5.48) in 2010 and 13.09 (SD 6.69) in 2016 (p < 0.001). Increasing age (OR 1.12, 95% CI 1.05-1.19, p = 0.0004), BMI (OR 1.08, 95% CI 1.04-1.11, p < 0.001), and male gender (OR 1.47, 95% CI 1.28-1.70, p < 0.001) were significantly associated with increased bariatric surgery wait times. Additionally, smoking status (OR 1.46, 95% CI 1.09-1.97, p = 0.0118) and obesity-related comorbidities particularly diabetes (OR 1.29, 95% CI 1.14-1.44, p < 0.001) and heart failure (OR 1.72, 95% CI 1.43-2.07, p < 0.001) were correlated with prolonged wait times for surgery. Socioeconomic variables including disability (OR 1.64, 95% CI 1.38-1.92, p < 0.001) and immigration status (OR 1.35, 95% 1.11-1.64, p = 0.003) were correlated with increased odds of longer wait times, as were regions with regionalized assessment and treatment centres (RATC) when referenced against centers of excellence (COEs) in number of days added with 20.45 (95% CI 13.20-27.70, p < 0.001). CONCLUSION: Wait times for bariatric surgery in a publicly funded, regionalized bariatric program are influenced by certain patient characteristics, socioeconomic variables, and institutional factors. This warrants further intervention and study to help improve these inequities when encountering potentially vulnerable populations awaiting bariatric surgery.

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.

Metabolic outcomes after bariatric surgery for Indigenous patients in Ontario.

BACKGROUND: In 2013, 18% of Canadian adults had obesity (body mass index [BMI] >30 kg/m2), compared with 25.7% of Canada's Indigenous population. Bariatric surgery is an effective treatment for obesity, but has not been studied in Canadian Indigenous populations. OBJECTIVES: To determine the effects of bariatric surgery in the Indigenous Ontario population. SETTING: Multicenter data from the publicly funded Ontario bariatric program and registry. METHODS: Prospectively collected data using all surgical patients between March 2010 and 2018 was included in initial analysis and included the following postoperative outcomes: diabetes, hypertension, and gastroesophageal reflux disease. Demographic characteristics, baseline characteristics, and univariate outcomes were assessed using Pearson Χ2 or t tests. Multivariable regression for BMI change was used with complete case analysis and multiple imputation. RESULTS: Of 16,629 individuals initially identified, 338 self-identified as Indigenous, 13,502 as Non-Indigenous, and 2789 omitted ethnicity and were excluded. Baseline demographic characteristics were not statistically different; rates of hypertension (P = .03) and diabetes (P < .001) were higher in the Indigenous population. Univariable analysis showed similar 1-year BMI change (Indigenous: 15.8 ± 6.0 kg/m2; Non-Indigenous: 16.1 ± 5.6 kg/m2, P = .362). After adjustment, BMI change was not different between groups at 6 months (effect size = .07, 95% confidence interval -.45 to .58, P = .803) and 1 year (effect size = -.24, 95% confidence interval -.93 to .45, P = .489). Rates of co-morbidities were similar at 1 year between the 2 populations, despite differences at baseline. Six-month and 1-year follow-up rates were higher in the Non-Indigenous population (P < .001, P = .005, respectively). CONCLUSIONS: Weight loss and resolution of obesity-related co-morbidities are similar in Indigenous and Non-Indigenous patients. Access to surgery, patient selection, and long-term results merit further investigation.

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.

Diagnostic Value of C-Reactive Protein Levels in Postoperative Infectious Complications After Bariatric Surgery: a Systematic Review and Meta-Analysis.

BACKGROUND: Bariatric surgery involves the risk of postoperative infectious complications, in particular, anastomotic leaks and intra-abdominal abscesses. C-reactive protein (CRP) is a nonspecific marker of inflammation which has gained attention as a test to predict postoperative infectious complications. This systematic review and meta-analysis evaluated the diagnostic value of CRP to detect postoperative infectious complications after bariatric surgery. METHODS: Search of MEDLINE, EMBASE, CENTRAL, and PubMed databases were performed. Articles measuring serum CRP postoperatively in patients with obesity undergoing bariatric surgery were included. Main outcomes included diagnostic value of postoperative serum CRP (area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV)). Diagnostic accuracy of included studies was assessed using QUADAS-2. RESULTS: Six studies including 2770 patients met the inclusion criteria. The derived CRP cutoff values were 71.4 mg/dL, 130.3 mg/dL, and 118.7 mg/dL on postoperative days (PODs) 1, 3, and 5, respectively. Pooled AUC was similar across PODs 1, 3, and 5 with AUC being highest on POD 5 (0.88 ± 0.07). PPV was between 19 and 21%, and NPV was between 98 and 99%. CRP levels were significantly higher (P < .0001) in postoperative infectious complication group versus the no complication group on PODs 3 and 5. CONCLUSIONS: High NPV and moderately high sensitivity on PODs 1, 3, and 5 may help predict patients who are at a low risk of infectious complication following bariatric surgery. High specificity on PODs 1 and 3 also indicates that it can be useful for early diagnosis of postoperative infectious complications.

Single- or double-anastomosis duodenal switch versus Roux-en-Y gastric bypass as a revisional procedure for sleeve gastrectomy: A systematic review and meta-analysis.

BACKGROUND: Laparoscopic sleeve gastrectomy (SG) is one of the most commonly performed bariatric procedure worldwide. There is currently no consensus on which revisional procedure is best after an initial SG. OBJECTIVES: To compare the efficacy and safety between single-anastomosis duodeno-ileal bypass (SADI) or biliopancreatic diversion with duodenal switch (BPD-DS) versus Roux-en-Y gastric bypass (RYGB) as a revisional procedure for SG. SETTING: University Hospital, Canada. METHODS: MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and PubMed were searched up to August 2018. Studies were eligible for inclusion if they compared SADI or BPD-DS with RYGB as a revisional bariatric procedure for SG. Primary outcome was absolute percentage of total weight loss. Secondary outcomes were length of stay, adverse events, and improvement or resolution of co-morbidities (diabetes, hypertension, or hypercholesterolemia). Pooled mean differences were calculated using random effects meta-analysis. RESULTS: Six retrospective cohort studies involving 377 patients met the inclusion criteria. The SADI/BPD-DS group achieved a significantly higher percentage of total weight loss compared with RYGB by 10.22% (95% confidence interval, -17.46 to -2.97; P = .006). However, there was significant baseline equivalence bias with 4 studies reporting higher initial body mass index (BMI) in the SADI/BPD-DS group. There were no significant differences in length of stay, adverse events, or improvement of co-morbidities between the 2 groups. CONCLUSION: SADI, BPD-DS, and RYGB are safe and efficacious revisional surgeries for SG. Both SADI and RYGB are efficacious in lowering initial BMI but there is more evidence for excellent weight loss outcomes with the conversion to BPD-DS when the starting BMI is high. Further randomized trials are required for definitive conclusions.

Intravenous Acetaminophen Versus Placebo in Post-bariatric Surgery Multimodal Pain Management: a Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Pain management after bariatric surgery is challenging. Recent trials have been exploring the role of intravenous (IV) acetaminophen in multimodal analgesic therapy. This systematic review and meta-analysis assessed the effect of IV acetaminophen compared to placebo for pain management after bariatric surgery. METHODS: A comprehensive search of MEDLINE, Embase, CENTRAL, and PubMed databases were performed. Randomized controlled trials (RCTs) comparing IV acetaminophen to placebo as part of multimodal pain management after bariatric surgery in patients with obesity were included. Key outcomes were analyzed using random-effects meta-analysis, and the certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). RESULTS: Four RCTs including 349 patients met the inclusion criteria, of whom 175 were provided IV acetaminophen and 174 were provided placebo. Patients given IV acetaminophen demonstrated a lower postoperative pain score (mean difference (MD) - 0.66, 95% CI - 1.03 to - 0.28, P < 0.001) 24 h after surgery and lower postoperative opioid use (MD - 6.44, 95% CI - 9.26 to - 3.61, P < 0.001; I2 = 0%) in morphine equivalent doses (MED) within 24 h compared with the placebo group. There was no significant difference in length of stay between groups (MD - 0.26, 95% CI - 0.55 to 0.03, P = 0.08). CONCLUSIONS: The use of IV acetaminophen after bariatric surgery is effective in reducing pain score after 24 h and postoperative opioid doses, but not length of stay. Provided the benefits of IV acetaminophen, its addition to postoperative care and enhanced recovery programs may be warranted.

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 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.

Bariatric Surgery in the Elderly Is Associated with Similar Surgical Risks and Significant Long-Term Health Benefits.

PURPOSE: Older age (> 60) has been considered a relative contraindication for bariatric surgery due to increased complication risk. This study examined the risks and benefits of bariatric surgery for patients older than 60 years in Canadian population. METHODS: This was a retrospective cohort study of the Ontario Bariatric Registry: a database recording peri-operative and post-operative outcomes of publicly funded bariatric surgeries across the province. Patients who completed 1 year follow-up, who underwent laparoscopic gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) between January 2010 and May 2013, were divided into older (> 60) and younger (> 60) cohorts, and outcomes were compared. RESULTS: Between January 2010 and May 2013, 3166 registry patients underwent LRYGB or LSG and completed 1-year follow-up. Of these, 204 (6.5%) were older than 60 years, with 175 (85.8%) undergoing LRYGB and 29 (14.2%) LSG. Demographics were similar, except for a higher number of males in the older group (59 (28.9%) versus 452 (15.3%) (p < 0.001)). No significant difference in complication rate was noted (15% for younger cohort versus 13.8% (p = 0.889)). The average percentage of excess weight loss was significantly higher in the younger population (60.72% versus 56.25% (p < 0.05)) overall, however not significantly in the LSG group. Reduction in medication use post-surgery for management of co-morbidities was significantly higher in the older patients (- 0.91 versus - 2.03 (p < 0.001)). CONCLUSION: The older cohort who underwent LRYGB or LSG was at no greater risk for intra-operative and post-operative complications and showed greater reduction in medication use post-surgery when compared to the younger cohort.

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.

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.

A Longitudinal Analysis of Short-Term Costs and Outcomes in a Regionalized Center of Excellence Bariatric Care System.

BACKGROUND: Evaluating how morbidity and costs evolve for new bariatric centers is vital to understanding the expected length of time required to reach optimal outcomes and cost efficiencies. Accordingly, the objective of this study was to evaluate how morbidity and costs changed longitudinally during the first 5 years of a regionalized center of excellence system. METHODS: This was a longitudinal analysis of the first 5 years of a bariatric center of excellence system. The main outcomes of interest were all-cause morbidity and cost for the index admission. Predictors of interest included patient demographics, comorbidities, annual hospital and surgeon volume, fellowship teaching center status, and year of procedure. Hierarchical regression models were used to determine predictors of morbidity and costs. RESULTS: Procedures done in 2012 (OR 0.65, 95%CI 0.52-0.79; p < 0.001), 2013 (OR 0.63, 95%CI 0.51-0.78; p < 0.001), and 2014 (OR 0.53, 95%CI 0.43-0.65; p < 0.001) all conferred a significantly lower odds of morbidity when compared to the initial 2009/2010 years. Surgeon volume was associated with a decreased odds of morbidity as for each increase in 25 bariatric cases per year the odds of all-cause morbidity was 0.94 lower (95%CI 0.88-1.00; p = 0.04). There was no significant variation at the hospital or surgeon level in perioperative outcomes. CONCLUSION: This study determined that volume was important even for high resource, fellowship-trained surgeons. It also found a decrease in morbidity over time for new centers. Lastly, there was little variation in outcomes across hospitals and surgeons suggesting that strict accreditation standards can help to ensure high quality across hospital sites.

The effect of health system factors on outcomes and costs after bariatric surgery in a universal healthcare system: a national cohort study of bariatric surgery in Canada.

INTRODUCTION: Previous data demonstrate that patients who receive bariatric surgery at a Center of Excellence are different than those who receive care at non-accredited centers. Canada provides a unique opportunity to naturally exclude confounders such as insurance status, hospital ownership, and lack of access on comparisons between hospitals and surgeons in bariatric surgery outcomes. The objective of this study was to determine the effect of hospital accreditation and other health system factors on all-cause morbidity after bariatric surgery in Canada. METHODS: This was a population-based study of all patients aged ≥18 who received a bariatric procedure in Canada (excluding Quebec) from April 2008 until March 2015. The main outcomes for this study were all-cause morbidity and costs during the index admission. All-cause morbidity included any documented complication which extended length of stay by 24 h or required reoperation. Risk-adjusted hierarchical regression models were used to determine predictors of morbidity and cost. RESULTS: Overall, 18,398 patients were identified and the all-cause morbidity rate was 10.1%. Surgeon volume and teaching hospitals were both found to significantly decrease the odds of all-cause morbidity. Specifically, for each increase in 25 bariatric cases per year, the odds of all-cause morbidity was 0.94 times lower (95% CI 0.87-1.00, p = 0.03). Teaching hospitals conferred a 0.75 lower odds of all-cause morbidity (95% CI 0.58-0.95, p < 0.001). Importantly, formal accreditation was not associated with a decrease in all-cause morbidity within a universal healthcare system. No health system factors were associated with significant cost differences. CONCLUSION: This national cohort study found that surgeon volume and teaching hospitals predicted lower all-cause morbidity after surgery while hospital accreditation was not a significant factor.