Biliopancreatic limb length for one anastomosis gastric bypass: efficacy and safety

The therapeutic effect of minigastric (one-anastomosis gastric) bypass is based on the mechanism of hypoabsorption. The length of the small intestine segment disconnected from the absorption processes of food nutrients and trace elements directly determines the efficacy of the intervention and the risk of postoperative complications, but its optimal choice is still debatable. The literature review analyzes anatomical and functional changes in the gastrointestinal tract after one-anastomosis gastric bypass, discusses the pathogenesis and the relationship of postoperative nutritional deficiencies with the biliopancreatic limb length. It has been shown that the current trend of bariatric surgery is the rejection of the routine choice of a 200 cm biliopancreatic loop in favor of 150-175 cm, while information on the variability of the small intestine length in patients with morbid obesity (from 250 to 1300 cm) does not allow us to consider this approach absolutely safe and effective. The results of experimental and clinical studies on comparable results of achieving remission of comorbid pathology with different lengths of the biliopancreatic loop, regardless of the volume of total weight loss, are presented. The feasibility of individual determination of the biliopancreatic loop length taking into account the total size of the patient's small intestine has not yet been established, which is reflected in the results of national and international consensus conferences. It has been shown that factors correlating with the intestine length of an obese patient are height, male sex, circumferences of the neck, chest, abdomen. As the minimum length of the functionally active segment of the small intestine (common loop) for the one-anastomosis gastric bypass, both 300 cm and 400 cm are discussed, and even the second value does not exclude the development of postoperative nutritional complications. For preoperative personalized planning of the ideal volume of hypoabsorption in one-anastomosis gastric bypass, the search continues for markers correlating with the small intestine total length, as well as other pathogenetic factors of morbid obesity and its complications.