The LSG is created by vertically removing 80% of the lateral side of the stomach, leaving a long, tubular gastric pouch or sleeve behind. Several mechanisms are at work in this procedure. The new stomach pouch has a much lower volume than a traditional stomach pouch, which helps to significantly reduce food intake and calorie consumption. The resection of the greater gastric curvature has an additional effect on the levels of gastrointestinal hormones in the stomach, including a decrease in plasma levels of ghrelin, a hormone that is released mostly from the gastric fundus and is responsible for increasing appetite. Weight reduction and T2DM improvement or remission after LSG is slightly lower than with RYGB, according to studies. Furthermore, some evidence suggests that improvement in T2DM after LSG is independent of weight loss. LSG's complication rates and weight-loss outcomes are comparable to those of RYGB and LAGB
