Gastric Sleeve Surgery

Gastric Sleeve Surgery, also known as Vertical Sleeve Gastrectomy (VSG) or Gastric Sleeve Resection, is a restrictive form of bariatric surgery that helps with weight loss by limiting food intake and controlling hunger sensations. The procedure calls for removing a large portion of the stomach, while keeping both ends of the stomach intact. It does not involve cutting or rerouting the small intestine and it does not require an implanted weight loss device.

  • The gastric sleeve may be performed either as a standalone bariatric procedure, or as the first step of the duodenal switch weight loss surgery.

Some individuals are either extremely obese or have health problems which disqualifies them from having gastric bypass surgery or gastric banding. In these cases, the gastric sleeve may be recommended, either as an alternative method or as the first step in a two step bariatric process. As a two step process, the gastric sleeve is usually followed up with intestinal rerouting to complete the duodenal switch procedure after sufficient weight loss has occurred.

If you are considering bariatric surgery, but either have concerns about gastric bypass and gastric banding or do not qualify for one of those procedures, you may want to ask your bariatric surgeon about gastric sleeve surgery and find out if this option is an appropriate choice for you.


Gastric Sleeve Diagram

Gastric sleeve surgery reduces the size of the stomach to help a person eat less and lose weight. To accomplish this, the surgeon removes about 75% of the stomach along the greater outside curvature. The new stomach is reconstructed to the shape of a thin tube, rather than a rounded pouch. The lesser inside curvature of the stomach is kept intact, extending from the normal stomach entrance (esophagus) to the normal stomach outlet (pyloric valve).

The effects of gastric sleeve surgery are:

  • restricts food intake
  • controls hunger

Following gastric sleeve surgery, food continues to move through the digestive system naturally, from the time it enters the stomach to the time it is released into the small intestine through the pyloric valve. The difference is that after surgery the amount of food that can be eaten at any one time is greatly reduced.

The surgery also helps to control hunger, because the upper portion of the stomach that produces the hunger stimulating hormone Ghrelin is removed during surgery.


  • Intestines not cut, rerouted, or bypassed, so does not cause malabsorption or nutritional deficiencies
  • Keeps pyloric valve intact, thus reducing ulcer risk and avoiding dumping syndrome
  • Food does not get stuck on way into stomach, as is possible with gastric banding
  • Can usually be performed laparoscopically, even on very obese patients
  • Safer and less complex than a combined restrictive/malabsorptive procedure, especially for patients with health problems
  • Option for patients with health concerns or medical issues, such as anemia, Crohn’s disease, anti-inflammatory drug use, or prior surgery, that prevents them from other bariatric procedures
  • Does not require a medical implant (gastric band) or adjustments
  • Average weight loss of 30% to 50% excess weight in first eighteen months
  • May be converted to duodenal switch for additional weight loss
  • Revision option for gastric band patients


  • Restrictive measures are less likely than malabsorptive procedures to cause significant weight loss, but even gastric bypass patients can have weight regain
  • Requires patient control to choose healthy, low-calorie, low-fat foods
  • Surgery is not reversible as a portion of the stomach is permanently removed
  • The new smaller stomach pouch may stretch over time
  • All surgery contains risk, including bleeding, blood clots, adverse reaction to anesthesia, infection, pneumonia, or complications
  • Procedure may not be covered by health insurance
  • Lack of published data for long-term weight loss results

Conversion to Duodenal Switch

The duodenal switch procedure involves both a gastric sleeve resection to restrict eating and intestinal rerouting to affect malabsorption. For some patients, both stages of the surgery are performed at one time. For other patients, including those with a BMI of 60 or greater, it may be necessary to perform the surgery as two separate operations due to health and safety concerns.

Because some patients do not qualify for a combined restrictive and malabsorptive operation, the gastric sleeve can help a patient start losing weight before further surgery is performed. After a few years of weight loss, a patient has usually lost enough excess weight to make it possible to continue with the intestinal changes to complete the duodenal switch procedure, if further weight loss is desired.

Gastric Sleeve Diet

The gastric sleeve procedure will restrict the amount of food that can be eaten at any one time, but it does not restrict any certain foods from the diet as the digestive system still functions normally. It is up to the patient to adopt the healthy diet and active lifestyle that will promote weight loss. Although your bariatric surgeon will give you specific diet guidelines, generally patients are advised to eat five small, healthy meals each day, with no snacking between meals. Certain foods must be removed from the diet for weight loss to occur, especially high-calorie and high-fat foods and beverages.

Weight Loss Results

The average amount of weight loss is typically 30% to 50% of excess weight in the first eighteen months after surgery. Some patients may reach their weight loss goals with the gastric sleeve, while others may want to proceed with the intestinal rerouting of the duodenal switch procedure. For patients who are planning to undergo the second stage of the duodenal switch, the timing of the second procedure will depend on rate of weight loss following gastric sleeve surgery.