Comparison of Mini Gastric Bypass and Roux-en-Y Gastric Bypass (RYSA)

Comparison of Two Operative Techniques - Mini Gastric Bypass and Roux-en-Y Gastric Bypass in the Treatment of Severe Obesity

This study compares Roux-en-Y gastric bypass with single anastomosis gastric bypass in a randomized prospective setting. This study also adresses the issue of bile reflux after MGB.

Roux-en-Y gastric bypass (RYGB) and single anastomosis gastric bypass (SAGB or mini gastric bypass, MGB) have both shown excellent weight-loss and effect on comorbidities such as type 2 diabetes. In this study eligible patients are randomized for either of the operations. Effects on glucose homeostasis as well as weight-loss and the effect on comorbidities are recorded during the follow-up. Before the surgery and at 6 and 12 months, all participants will undergo body composition measurements (bioimpedance, MRI and DEXA), mixed meal tests and oral glucose tolerance tests, calorimetry and biopsies of skin, subcutaneous fat and muscle will be obtained and samples of urine, feces and saliva are collected. At these timepoints, all patients will fill out questionnaires regarding psychocological, social and physical health and wellbeing. Interim analysies will be done for the first 60 patients (30 per group) after 3 months, in which safety issues and trial setup is reviewed. If there are no problems with safety and setup, the trial can be carried out according to initial plan. At 12 months, all outcomes for all patients will be analyzed. Main outcome is weight-loss one year after the surgery. Follow-up continues at 24months, 5 years and 10 years after the surgery and follow-up data will be analyzed accordingly. Also, MGB has been feared to cause bile reflux. The first 30 MGB patients will undergo a gastroscopy and a hepatobiliary scintigraphy for bile reflux detection at 6 months.

Main outcome is weight-loss at 1 yewar after the operationoperation. Weight-loss is calculated as excess weight-loss compared to the preoperative weight 2 months before the operation.

2 months before the operation glucose homeostasis status is studied (oral glucose tolerance test). Oral glucose tolerance tests will be repeated at 6months and 12 months. Continuos glucose monitoring will be done before the operation at operation and 6 months after the operation

All patients undergo a gastroscopy prior to inclusion. Patients with Barrets esophagus or LA B-C esophagitis are excluded. The first 30 patients, who are randomized to Mini Gastric Bypass will undergo a gastroscopy and a hepatobiliary scintigraphy 6 months after the operation. At hepatobiliary scintigraphy the amount of bile reflux is calculated as the amount of tracer found in the gastric pouch or esophagus in relation to total amount of tracer in the liver.

Inclusion Criteria: BMI>35 Exclusion Criteria: Pregnancy Previous bariatric surgery Anemia esophagitis (LA B-D) esophageal intestinal metaplasia

Saarinen T, Merilainen S, Koivukangas V, Pietilainen KH, Juuti A. Prospective randomized controlled trial comparing the efficacy and safety of Roux-en-Y gastric bypass and one-anastomosis gastric bypass (the RYSA trial): trial protocol and interim analysis. Trials. 2019 Dec 30;20(1):803. doi: 10.1186/s13063-019-3898-y.

Saarinen T, Pietilainen KH, Loimaala A, Ihalainen T, Sammalkorpi H, Penttila A, Juuti A. Bile Reflux is a Common Finding in the Gastric Pouch After One Anastomosis Gastric Bypass. Obes Surg. 2020 Mar;30(3):875-881. doi: 10.1007/s11695-019-04353-x.