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Updated: Nov 5, 2025

One-anastomosis Gastric Bypass OAGB in Rats
Published on: November 10, 2018
Natural orifice transluminal endoscopic one-anastomosis gastric bypass: a feasibility study using porcine model
Chin Hong Lim1, Zhen Jin Lee2, Baldwin Yeung3
1Department of Upper Gastrointestinal & Bariatric Surgery, Division of Surgery, Singapore General Hospital, Academia, 20 College Road, Singapore, 169856, Singapore. lim.chin.hong@singhealth.com.sg.
Introduction:
Endoscopic bariatric therapies (EBT) are emerging as effective therapies in the management of overweight patient with or without metabolic syndrome. Unfortunately most procedures only restrict the gastric volume without altering the underlying metabolism which is seen in surgical patients. The aim of this study was to investigate the feasibility and limitations of a natural orifice trans-luminal endoscopic surgery (NOTES) one anastomosis gastric bypass (OAGB).
Methods:
NOTES OAGB was performed in three porcine models. The steps of the procedure can be divide as follows: (1) Endoscopic sleeve gastroplasty. (2) Trans-gastric access to peritoneal cavity. (3) Identification of a loop of jejunum. (4) Introduction of the jejunal loop into the stomach. (5) Creation of the gastro-jejunostomy with lumen-apposing metal stent (LAMS). (6) Closure of gastric pylorus with overstitch system.
Results:
All the animals underwent successful NOTES of OAGB. The mean weight for the animals was 34.3 kg (32-37 kg). The mean procedure time was 250 min (300 min for first animal and 180 min for third animal). The average bypassed bilio-pancreatic limb was 98 cm (range 65-130 cm).
Conclusions:
This study has provided proof-of-principle in a preclinical model that a NOTES approach can be used to perform OAGB and, therefore, merits additional evaluation and consideration.

