Gastric sleeve surgery  is a type of obesity surgery in which a significant reduction in stomach capacity and a forced and physiological restriction on the amount of food consumed is performed. In this type of surgery, 80% of the elastic part of the stomach, including the part of the stomach that secretes the hormone Ghrelin, a hormone that plays an important role in creating appetite, or the hormone of hunger, is separated from the stomach and the rest of the stomach is punched. The remaining part  of these operations is repaired with titanium stiches and 80% of the gastric tissue is removed from the body.  
Patients after surgery due to significant shrinkage of the stomach and the removal of the hormone ghrelin physiologically, have very little inclination to eat and even if they do not, can not consume too much food. This restriction remains with subtle changes for the rest of your life, and surgery in the first year causes a significant weight loss and then keeps this weight loss the same.  
In this method, which is one of the restrictive methods, after entering the abdomen with laparoscopy, about 80% 
of the stomach volume is removed with a device that performs cutting and sewing at the same time and is removed from the abdomen. Therefore, by removing an area of the stomach that secretes the hunger hormone (Ghrelin), the patient's appetite is normalized and by eating a few tablespoons, fullness and satiety is achieved, and since the above-mentioned hormone acts against insulin, by removing And its sharp decline from a few days after surgery, diabetes begins to control. Among the advantages of this method is the easier surgical technique and shorter length of operation than combined operations. before, it was not possible to perform combined operations on Crohn’s or Ulcerative colitis patients , but now with this method its preferred and an efficient method.  
Sometimes in patients who have too much fat in the abdomen or the size of the liver is too large and heavy due to fat. When entering the abdomen, the surgeon is not able to perform combined operations due to the impossibility of changing the location of the intestine and insufficient vision. So it is done in two stages. In the first stage, the sleeve operation is performed, and after 8 months to a year and weight loss and improvement of intra-abdominal anatomy, the second stage of the 
operation and conversion of the sleeve into one of the combined operations is performed. However, in many cases, the patient responds adequately to the first stage (gastric sleeve) and there is no need to perform the second stage.  
Who will benefit from sleeve surgery? The choice of surgery technique is chosen by the medical team based on preoperative advice, examinations, and review of your preoperative lifestyle, but generally in people with severe and unavoidable binge eating, very high weights, and illness. They have a specific and long metabolism like diabetes, sleeve is not the first option of surgery.  
Disadvantages :  1.In snack-eaters and sweet eaters, it does not initially give the ideal answer. For example, if a person is 50 kg overweight and is more snack-eating or sweet-eating and undergoes sleeve surgery, they may end up with 20 to 25 kg overweight. Lose yourself (about 40 to 50%) and stop losing weight very soon. In these cases, combined operations are recommended. 
2.If not done in the right person, it is associated with a high rate of recurrence of obesity in the long run (after one to two years), which in some statistics is up to 50% is mentioned. Therefore, the surgeon must be very careful in choosing the method. 3.  This method is not recommended for people with gastroesophageal reflux disease (GERD) or heartburn because it makes it worse and may cause esophageal ulcers and other long-term problems. Therefore, in this method, maximum attention should be paid to endoscopy before the patient's operation, so that in case of moderate to severe endoscopic symptoms (esophagitis), other appropriate operations can be used to improve this complication. 4.Since in this method part of the stomach is removed from the body, the gastric sleeve is irreversible.  
5. Since nothing is done on the intestines in the gastric sleeve, and a number of hormones that are anti-insulin and are secreted from the early parts of the small intestine, it has no effect on the treatment of diabetes by combination surgery.