Defining Global Benchmarks in Bariatric Surgery

A Retrospective Multicenter Analysis of Minimally Invasive Roux-en-Y Gastric Bypass and Sleeve Gastrectomy

Daniel Gero, MD; Dimitri A. Raptis, MD, MSc, PhD; Wouter Vleeschouwers, MD; Sophie L. van Veldhuisen, MD; Andres San Martin, MD; Yao Xiao, MD; Manoela Galvao, MD; Marcoandrea Giorgi, MD; Marine Benois, MD; Felipe Espinoza, MD; Marianne Hollyman, MD, PhD; Aaron Lloyd, MPH; Hanna Hosa, MD; Henner Schmidt, MD; José Luis Garcia-Galocha, MD; Simon van de Vrande, MD; Sonja Chiappetta, MD; Emanuele Lo Menzo, MD; Cristina Mamédio Aboud, RN, MSc; Sandra Gagliardo Lüthy; Philippa Orchard, MD; Steffi Rothe, MBA; Gerhard Prager, MD; Dimitri J. Pournaras, MD, PhD; Ricardo Cohen, MD; Raul Rosenthal, MD; Rudolf Weiner, MD; Jacques Himpens, MD, PhD; Antonio Torres, MD, PhD; Kelvin Higa, MD; Richard Welbourn, MD; Marcos Berry, MD; Camilo Boza, MD; Antonio Iannelli, MD; Sivamainthan Vithiananthan, MD; Almino Ramos, MD; Torsten Olbers, MD, PhD; Matias Sepúlveda, MD; Eric J. Hazebroek, MD, PhD; Bruno Dillemans, MD; Roxane D. Staiger, MD; Milo A. Puhan, MD, PhD; Ralph Peterli, MD; Marco Bueter, MD, PhD


Annals of Surgery. 2019;270(5):859-867. 

In This Article

Abstract and Introduction


Objective: To define "best possible" outcomes for bariatric surgery (BS)(Roux-en-Y gastric bypass [RYGB] and sleeve gastrectomy [SG]).

Background: Reference values for optimal surgical outcomes in well-defined low-risk bariatric patients have not been established so far. Consequently, outcome comparison across centers and over time is impeded by heterogeneity in case-mix.

Methods: Out of 39,424 elective BS performed in 19 high-volume academic centers from 3 continents between June 2012 and May 2017, we identified 4120 RYGB and 1457 SG low-risk cases defined by absence of previous abdominal surgery, concomitant procedures, diabetes mellitus, sleep apnea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, anticoagulation, BMI>50 kg/m2 and age>65 years. We chose clinically relevant endpoints covering the intra- and postoperative course. Complications were graded by severity using the comprehensive complication index. Benchmark values were defined as the 75th percentile of the participating centers' median values for respective quality indicators.

Results: Patients were mainly females (78%), aged 38±11 years, with a baseline BMI 40.8 ± 5.8 kg/m2. Over 90 days, 7.2% of RYGB and 6.2% of SG patients presented at least 1 complication and no patients died (mortality in nonbenchmark cases: 0.06%). The most frequent reasons for readmission after 90-days following both procedures were symptomatic cholelithiasis and abdominal pain of unknown origin. Benchmark values for both RYGB and SG at 90-days postoperatively were 5.5% Clavien-Dindo grade ≥IIIa complication rate, 5.5% readmission rate, and comprehensive complication index ≤33.73 in the subgroup of patients presenting at least 1 grade ≥II complication.

Conclusion: Benchmark cutoffs targeting perioperative outcomes in BS offer a new tool in surgical quality-metrics and may be implemented in quality-improvement cycle.


With growing complexity and cost of modern surgical practice, structured quality assessment became mandatory.[1,2] Benchmarking is among the most popular quality management tools in companies' process improvement cycles.[3]

Benchmarking is a market-based learning method by which a company seeks to identify best practices that produce superior results in other firms, and to enhance its own competitive advantage by adopting them.[4] In the surgical literature procedure-specific outcome benchmarks are largely lacking.[5]

Recent studies in the field of visceral surgery established benchmark cutoffs for best achievable patient-centered outcomes in well-defined low-risk patient cohorts, allowing comparison among centers and patient groups over time and between procedures.[2,6–9]

Bariatric surgery (BS) remains the most effective treatment for severe obesity and associated diseases.[10] The annual caseload of BS worldwide has doubled during the past decade, and approached 700,000 operations in 2016.[11] Together, the Roux-en-Y gastric bypass (RYGB) and the sleeve gastrectomy (SG) constitute more than 80% of bariatric procedures worldwide.[11] Although frequently performed, both procedures and follow-up care are not highly standardized,[12,13] posing a challenge in defining evidence-based cutoffs for quality indicators for the peri- and postoperative course.[14]

Our aim was to identify the highest achievable quality (ie, the global benchmarks) in BS, by assessing patient-centered outcome indicators in low-risk patients who underwent SG or RYGB in high-volume bariatric centers. The identified benchmarks are expected to improve surgical quality by providing "goals" in postoperative outcomes and may therefore assist patients and healthcare providers in medical decision-making.