[Clinical significance and research status of small intestinal limb length in Roux-en-Y gastric bypass]

Roux-en-Y gastric bypass (RYGB) is an important bariatric and metabolic surgical procedure, and the design of intestinal limb lengths is a key factor affecting weight loss outcomes, metabolic improvements, and postoperative nutritional status. Currently, there are no established international standards for the optimal lengths of the biliopancreatic limb, alimentary limb, and common channel. This article reviews the evolutionary history of RYGB and its common classification, with a focus on analyzing the impact of the lengths of the alimentary limb, biliopancreatic limb, common channel, and total alimentary limb on postoperative weight loss outcomes and complications. The length of the alimentary limb can be designed based on the patient's BMI stratification: for patients with BMI ≥ 50 kg/m², 130-150 cm is recommended; for those with BMI <50 kg/m², ≤ 100 cm is recommended. The length of the biliopancreatic limb ranges from 50-150 cm, and the sum of the lengths of the biliopancreatic limb and alimentary limb should be controlled at approximately 200 cm, as excessive length may increase the risk of adverse events. A common channel length exceeding 400 cm can reduce the risk of complications. The total length of the alimentary limb should be greater than 400 cm to balance weight loss and nutritional safety. However, the optimization of intestinal limb lengths still needs to consider the patient's baseline characteristics and the type of surgical procedure. This article aims to provide guidance for clinical decision-making regarding intestinal limb lengths in RYGB based on guidelines, emphasizing the importance of formulating individualized plans in conjunction with patient characteristics, with particular attention to ethnic-specific factors relevant to the Chinese population to optimize surgical outcomes.