A reduction of 15-20% of the stomach from its original size is accomplished with a sleeve gastrectomy - a technique of bariatric surgery. A large portion of the stomach is surgically removed at the greater curve. There is sufficient improvement in comorbidity and weight loss mechanisms due to gastric restriction. It is a 2-stage surgery and is a widely recommended stand-alone procedure. The operation restricts the amount of food intake due to the decrease in the appetite-prompting hormone ghrelin.
Laparoscopic adjustable gastric banding: A flexible, adjustable and inflatable band is placed around the proximal stomach. A gastric pouch of about 15 mL in volume is created along with a small stoma. Adjustability is with the help of a reservoir system attached to the band that adds or removes the saline from the inflatable band. The reservoir is accessible through a port that is attached to the band with a catheter. It takes approximately 2 years to experience about 60% loss of surplus weight.
Biliopancreatic diversion with duodenal switch: A tubular stomach is created and the duodenum is divided past the pyloric valve along with the ileum. The distal end is anastomosed to the proximal duodenum and a common channel is distally created with a Y-anastomosis. Protein absorption is minimised and fat malabsorption occurs resulting in weight loss.