Background and Aims: Metabolic surgery is evolving and safer, but more effective alternatives are constantly sought for. The single-anastomosis gastric bypass was first described in 2001, and although controversial, this operation is gaining fast in popularity worldwide. This review is aiming at a critical evaluation of the procedure in the light of the literature.

Methods: The abstracts of 73 articles were reviewed, and after removal of case studies, duplicates, and irrelevant articles, 10 articles remained for closer review.

Results: Several thousand of this operation have been performed for more than 15 years. It is claimed to be an easier, safer, faster, and more effective metabolic operation compared to the standard Roux-en-Y gastric bypass. The proponents of this operation also claim that this operation is easier to revise and reverse, leaving more options compared to the situation after standard bypass in case of failure. However, there is much controversy surrounding this method, mainly concerning the possible harmful and in the long-term even carcinogenic effects of biliopancreaticoduodenal reflux in the gastric pouch.

Conclusion: The single-anastomosis gastric bypass may be an attractive alternative metabolic operation. However, further studies with robust, long-term follow-up are needed.