The sleeve gastrectomy is an operation in which we take the stomach (which is about the size of a football) and we remove about 85% of the stomach and take that out and discard it. What you're left with is a stomach that is in the shape of a tube which kind of looks like a banana. Because of that, patients are able to eat much less food and that in turn causes them to lose a significant amount of weight. This operation is permanent and is a lifelong change for the patient.