# The Banded One-Anastomosis Gastric Bypass Trial (RiMini Trial): Protocol of a Prospective Single-Center Randomized Controlled Trial

## TL;DR

This study will test if adding a silicone ring to a gastric bypass surgery improves long-term weight loss in patients.

## Contribution

The study introduces a randomized controlled trial to evaluate the long-term effectiveness of banded one-anastomosis gastric bypass.

## Key findings

- The trial will compare weight loss outcomes with and without a silicone ring over five years.
- It will assess obesity complications, quality of life, and adverse events related to the procedures.
- The study aims to provide evidence on whether the silicone ring reduces long-term weight regain.

## Abstract

Long-term recurrent weight gain remains a persistent challenge in metabolic bariatric surgery (MBS). One strategy for managing recurrent weight gain involves the placement of a non-adjustable silicone ring around the reduced stomach pouch. This technique may lead to more significant weight loss and a reduced risk of long-term recurrent weight gain. Although several studies have demonstrated the effectiveness of silicone rings in combination with Roux-en-Y gastric bypass (RYGB), randomized studies providing long-term data on the effectiveness of primary banded one-anastomosis gastric bypass (OAGB) are lacking.

A total of 210 patients will be included in this prospective, non-blinded, single-center randomized controlled trial. The primary endpoint is the difference in total weight loss percentage (%TWL) 5 years post-surgery. Secondary outcomes include excess weight loss percentage (%EWL), changes in obesity complications, quality of life, and adverse events related to the surgical procedures. The study population will consist of patients eligible for primary OAGB aged 18 years and older.

The RiMini trial aims to investigate whether there is a significant difference in long-term weight reduction expressed as %TWL in patients undergoing an OAGB with or without the addition of a silicone ring 5 years after surgery.

This study is registered at Clinicaltrials.gov (NCT05472922) on the 25th of July, 2022.