A Sleeve Gastrectomy involves removing approximately two thirds of the stomach through keyhole surgery effectively turning the stomach, which is like a big bag normally into a tube.
The biggest advantage is that there is no foreign device to fail or cause obstruction and there is no major alteration in the gastro-intestinal tract. Patients will feel full with an entrée size portion, but also once they get beyond the normal post-operative recovery period can eat most foods, which is a major advantage over gastric banding.
The other major effect of the procedure is to remove the part of the stomach that secretes Ghrelin, a hormone that plays a major role in determining how hungry we get. When normal people go on a diet, as they lose weight the stomach starts to produce more and more Ghrelin, which acts on the brain to increase appetite. Often people who are dieting have the sensation that they are starving to death. Patients who have had a sleeve gastrectomy generally have a greatly reduced appetite, and as they lose weight they do not suffer the hunger pains experienced by dieters.