Bariatric surgery is effective on obesity, which can significantly improve the metabolic diseases of obesity patients, especially the type 2 diabetes. However, the surgical proce-dures of bariatric and metabolic surgery are still evolving and in progress. One anastomosis gastric bypass (OAGB) is the latest bariatric surgery recognized by the international bariatric and metabolic surgery community. The authors review the relevant literatures at home and abroad, and introduce the development history, surgical skills, clinical efficacy, status quo and adaptability of OAGB.

Bariatric surgery is the most effective treatment for patients with severe obesity, which can significantly improve the metabolic disorders, especially type 2 diabetes mellitus. Bariatric and metabolic surgery is the latest and fastest-growing branch of surgery, with the types of procedure and other novel treatment modalities are still evolving and in progress. The authors summarize the recent advancement related to novel bariatric and metabolic surgery in the treat-ment of morbid obesity and type 2 diabetes mellitus in recent years through literature search, which can be divided into the following three parts: (1) novel surgical procedures and new guideline of indication. Sleeve gastrectomy and Roux-en-Y gastric bypass are the most performed bariatric surgery. Duodenal switch or the variant of one anastomosis duodenal ileostomy are also accredited procedures but been less performed. One anastomosis gastric bypass is the most recently accredited bariatric surgical procedures with better safety profile and weight loss efficacy than most of the procedures. For other novel procedures, bipartition procedure may be the next accredited proce-dure. A new worldwide guideline is recently launched and the indication for bariatric surgery is lowered BMI 27.5 kg/m 2 for Asian. (2) The effect and mechanism of bariatric surgery. Bariatric surgery can significantly reduce the incidence of cardiovascular disease and mortality in obese patients. The main beneficiary group is patients with diabetes mellitus. Along with the recent basic research and the success of new gut hormone related drugs, the mechanism of bariatric surgery can be mostly attributed to gut hormonal effect, however, gastric volume still play an important role. (3) Novel obesity treatment modalities. Endoscopic obesity treatment has a major progress in the success of endoscopic gastroplasty by endoscopic suturing designs. More noteworthy is the development of new intestinal hormone drug therapy, which can achieve a weight loss of 14% in one year by injec-ting once a week glucagon-like peptide-1 preparation, and then combining two or three intestinal hormone drugs can achieve a weight loss of 24% in one year, which is close to the effectiveness of bariatric surgery. Pharmacologic treatment of obesity is very promising and expected. With the increasing severity of obesity and diabetes mellitus in the world, in addition to the explosive develo-pment of bariatric and metabolic surgery in recent years, many new surgical methods and new treatments, especially new and effective intestinal hormone related therapeutic drugs, have been developed. The success of bariatric and metabolic surgery depends on a multidisciplinary team with rich clinical experience: precise preoperative planning and comprehensive postoperative manage-ment, as well as patient understanding and cooperation, in order to achieve the best results.