Defining Benchmarks in Bariatric Surgery

Study Overview
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Brief Summary
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Aim: To define benchmark outcomes in minimally-invasive primary bariatric surgery. Design: Multicenter retrospective cohort study. Assessed outcomes: Morbidity as defined by the Clavien-Dindo classification for surgical complications, the Comprehensive Complication Index® (CCI®) at discharge, at 3 months and at latest follow-up. Evolution of body mass index (BMI) will be also analyzed. Hospital eligibility: High volume centers (> 200 bariatric operations per year) from at least three continents, maintaining a prospective database, as well as having published previously critically on their outcome. Study population: Adult patients who underwent primary minimally invasive (laparoscopic / robotic) Roux-en-Y gastric bypass or sleeve gastrectomy from 1st of June 2012 to 31st of May 2017. Patient Exclusion criteria: detailed later. Data collection Deadline: 1st September 2017 - 30 April 2018

Detailed Description
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Background With the growing complexity and cost of modern surgical practice, quality assessment becomes mandatory. The notion of quality and quality assessment is widely recognized and used in the world of business and manufacturing. A possible tool of quality assessment is benchmarking. Benchmarking is a process of measuring performance by comparison to the outcomes achieved by the best service provider in a specific domain. Usually, a benchmark describes the ''best possible'' outcome of a benchmarking subject to whom comparison can be performed. In the surgical community, however, such benchmarks - best possible outcomes - for specific procedures, not just the pooled overall performance, are lacking. In 2016, a first landmark study defining benchmark outcomes for liver resection was published in Annals of Surgery by a group of international authors invited and guided by our department. More recently, further surgical outcomes (liver transplantation, minimally invasive esophagectomy) have been benchmarked and have been accepted for publication. Since laparoscopic bariatric surgery has become a standardized and widely performed procedure worldwide, quality assessment is of major importance. To identify the best possible outcomes (i.e. the benchmarks), data from high-volume centers (based on official IFSO criteria) in low risk patients will be analyzed. These benchmarks will serve as optimal outcomes for comparison with single center outcomes, high-risk patients and future developments. Aim The primary aim is to define benchmark outcomes based on assessment of post procedural complications according to the Clavien-Dindo classification for surgical complications and the comprehensive complication index CCI™ at discharge and at 90-days. The CCI® expresses morbidity on a continuous numeric scale from 0 (no complications) to 100 (death) by weighing all postoperative complications according to the Clavien-Dindo classification for their respective severity. Secondary outcome measure are patient survival and excess BMI loss (EBMIL). Data Security This multicenter international study is designed to harvest prospectively collected retrospective data via an encrypted (i.e. Secure Sockets Layer (SSL) protocol) online platform (https://bbenchmarks.org/) that meets Food and Drug Administration (FDA) standards and is accessible only by secured login membership. Confidential center specific data: Centers' outcomes will be individually analyzed in a first step to screen for center-specific differences. Benchmarks will be computed from each center's results in a second step. No center-specific data will be published. Instead, all complications or adverse outcomes will be anonymously reported, as fractions of the total study population. Each center, of course, will be free to publish their own data, as they wish. Further use of cohort data: Future studies based on the collected data may emerge from this multicenter study, such as comparing outcomes in patients with or without specific comorbidities with benchmark outcomes. For further data usage, additional ethics approval may be required.

Official Title
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Defining Benchmarks in Bariatric Surgery - A Global Analysis of Laparoscopic Roux-en-Y Gastric Bypass and Sleeve Gastrectomy

Conditions
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Benchmark, Bariatric Surgery, Roux-en-y Gastric Bypass, Sleeve Gastrectomy, Complications

Intervention / Treatment
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* Procedure: bariatric surgery (RYGB or SG)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients of 18-65 years Low risk profile (please read exclusion criteria), Maximum preoperative BMI of 50 kg/m2 Primary laparoscopic/robotic proximal Roux-en-Y gastric bypass or sleeve gastrectomy Documented follow-up of at least 90 days Exclusion Criteria: Open surgery Previous intra-abdominal surgery (including previous bariatric surgery) Pre-operative BMI over 50 kg/m2 Age over 65 years Cardiovascular disease (e.g. cardiac arrhythmia, stroke, coronary artery disease) (Hypertension is allowed) History of thromboembolic events and/or therapeutic anticoagulation Diabetes mellitus (Type I and Type II, as defined by the American Diabetes Association) Obstructive sleep apnea (recurrent episodes of upper airway collapse during sleep) Chronic obstructive pulmonary disease (FEV1/FVC<0.7) Chronic kidney disease (eGFR < 30ml/min/1.72 m2) Inflammatory bowel disease (ulcerative colitis, Crohn's) Immunosuppression therapy (e.g. steroids, calcineurin inhibitors, etc) Patients who underwent associated procedures (for example: cholecystectomy, hiatoplasty, liver biopsy) ASA score > 2

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| University Hospital Zurich<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| St Pierre University Hospital, Brussels, Belgium<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Sana Klinikum, Offenbach, Germany<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Complutense University of Madrid, Spain<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Musgrove Park Hospital, Taunton, UK<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| University of Gothenburg, Sweden<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| AZ Sint-Jan Hospital in Bruges, Belgium<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Bristol<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Cleveland Clinic, Weston, Florida, USA<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Oswaldo Cruz German Hospital, Sao Paolo, Brazil<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Clínica Las Condes, Santiago, Chile<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Brown University, Providence Rhode Island<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Fresno Bariatric, CA, USA<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Rijnstate Hospital, Arnhem, The Netherlands<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| CHU Nice, France<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Claraspital Basel, Switzerland<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Gastro-Obeso-Center Advanced Med Inst, Brazil<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Hospital Dipreca Santiago Región Metropolitana , Chile<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|
| Medical University Wien, Austria<br> | Procedure: bariatric surgery (RYGB or SG)<br>* laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy for severe obesity<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Benchmark outcomes (best achievable outcomes after bariatric surgery) | Comprehensive Complication Index (http://www.assessurgery.com/calculator_single/) | 30 days postoperatively | 
| Benchmark outcomes (best achievable outcomes after bariatric surgery) | Comprehensive Complication Index (http://www.assessurgery.com/calculator_single/) | 90 days postoperatively | 
| Benchmark outcomes (best achievable outcomes after bariatric surgery) | Comprehensive Complication Index (http://www.assessurgery.com/calculator_single/) | 180 days postoperatively | 
| Major complications after bariatric surgery | Clavien-Dindo grade > IIIa | 30 days postoperatively | 
| Major complications after bariatric surgery | Clavien-Dindo grade > IIIa | 90 days postoperatively | 
| Major complications after bariatric surgery | Clavien-Dindo grade > IIIa | 180 days postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Case-mix within centers | proportion of benchmark cases | 5 years | 
| Excess weight loss after bariatric surgery | Body-mass index (kg/m2) | 1-year postoperatively | 
| Excess weight loss after bariatric surgery | Body-mass index (kg/m2) | 3-years postoperatively | 
| Excess weight loss after bariatric surgery | Body-mass index (kg/m2) | 5-years postoperatively |