Related Experiment Video
Updated: Aug 28, 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 Human Cadavers
Chin Hong Lim1, Zhen Jin Lee2, Tiffany Lye2
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.
Background:
Endoscopic bariatric therapies (EBT) has emerged as an effective treatment in the management of the patient with obesity. Unfortunately, most procedures involve only the restriction of gastric volume without altering the underlying metabolism. The objective of this study was to investigate the practicability and limitations of the metabolic altering procedures: "One anastomosis gastric bypass (OAGB)" with "natural orifice transluminal endoscopic surgery (NOTES)" on human cadavers.
Methods:
We performed OAGB with NOTES approach in 3 human cadavers. The steps of the procedure can be divided as follows: step 1, endoscopic sleeve gastroplasty (ESG); step 2, trans-gastric access to peritoneal cavity; step 3, identification of suitable loop of jejunum; step 4, introduction of the jejunal loop into the stomach; step 5, creation of the gastro-jejunostomy with lumen-apposing metal stent (LAMS); step 6, gastric pylorus occlusion with overstitch.
Results:
We performed OAGB with NOTES in 3 human cadavers with bypassed bilio-pancreatic limb of 55, 75, and 105 cm from the pylorus. The average weight for the cadavers was 64.9 kg (61.2-71.7 kg). The mean procedure time was 157 min. The optimal bypassed length for the procedure was 105 cm.
Conclusions:
This study has provided proof-of-principle in a pre-clinical cadaveric model that NOTES approach can be used to perform OAGB and, therefore, merits additional evaluation and consideration in surviving porcine model.

