Laparoscopic Roux-en-Y gastric bypass versus laparoscopic mini gastric bypass in the treatment of obesity: study protocol for a randomized controlled trial

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is considered the gold standard in bariatric surgery, achieving durable long-term weight loss with improvement of obesity-related comorbidities. Lately, the laparoscopic mini gastric bypass (LMGB) has gained worldwide popularity with similar results to LRYGB in terms of weight loss and comorbidity resolution. However, there is a lack of randomized controlled trials (RCT) comparing LMGB and LRYGB. This article describes the design and protocol of a randomized controlled trial comparing the outcomes of these two bariatric procedures.

The trial is designed as a single center, randomized, patient and observer blinded trial. The relevant ethics committee has approved the trial protocol. To demonstrate that LMGB is not inferior to LRYGB in terms of excess weight loss (EWL) the study is conducted as a non-inferiority trial with the sample-size calculations performed accordingly. EWL 12 months after surgery is the primary endpoint, whereas 3-year EWL, morbidity, mortality, remission of obesity related comorbidities, quality of life (QOL) and hormonal and lipid profile changes are secondary endpoints. Eighty patients, 18 years or older and with a body mass index (BMI) between 35 and 50 kg/m² who meet the Swiss guidelines for the surgical treatment of morbid obesity will be randomized. The endpoints and baseline measurements will be assessed pre-surgery, peri-surgery and post-surgery (fixed follow up measurements are at discharge and at the time points 6 weeks and 12 and 36 months postoperatively).

With its 3-year follow up time, this RCT will provide important data on the impact of LMGB and LRYGB on EWL, remission of comorbidities, QOL and hormonal and lipid profile changes.

ClinicalTrials.gov, NCT02601092. Registered on 28 September 2015.