Definition and Overview

Sleeve gastrectomy (gastric sleeve surgery) is an irreversible weight loss surgery that reduces the size of the stomach by up to 75 percent to drastically decrease food intake. With obesity becoming a global concern, this procedure, which is much less complicated compared to other types of bariatric surgery, has increased in popularity in recent years.

Who Should Undergo and Expected Results

Sleeve gastrectomy is recommended for individuals who:

  • Have a body mass index (BMI) of 40 and above, which is considered morbidly obese
  • Have a BMI of at least 30 with at least one obesity comorbidity such as sleep apnea, type 2 diabetes, and heart disease
  • Weigh 75 pounds more than their ideal body weight

It is also typically recommended for obese individuals who have not lost weight despite drastic lifestyle modifications, whose obesity is not related to other underlying conditions like thyroid problems, and who do not prefer lap band surgery, which involves using a band to reduce the size of the stomach. Lap bands often need to be adjusted regularly, which is not only inconvenient but also increases the risk of surgical complications.

Sleeve gastrectomy may also be recommended for children, provided they have undergone comprehensive surgical screening and counseling prior to the procedure and the benefits, such as the prevention of long-term obesity-related chronic conditions, far outweigh the risks.

Also, the procedure can be performed as the first stage of gastric bypass, which requires more hours of operation that can be risky for obese patients due to the amount of anesthesia needed. Gastric sleeve surgery may be carried out first to give the patient enough time to lose considerable weight before the bypass is performed. However, due to the potential weight loss associated with sleeve gastrectomy, which is at least 60 percent, a bypass is sometimes no longer necessary.

As one of the most popular bariatric procedures (accounts for more than 42 percent of all weight loss surgeries in 2013), sleeve gastrectomy promotes significant weight loss within the next two years following the operation and the reversal of obesity-related problems. It also has minimal complications due to quicker operation time, less amount of anesthesia needed, and minimal reorganization of the digestive tract. Finally, although restrictive, the procedure does not usually result in malabsorption and deficiency of nutrients.

How Does the Procedure Work?

Prior to the surgery, both the surgeon and the patient will meet to discuss:

  • The actual procedure including preparation, surgical time, and the team of doctors who will be involved in the surgery
  • Risks and complications of the surgery
  • Benefits of the surgery
  • Postoperative care
  • Long-term weight loss management
  • Other concerns the patient may raise
  • Psychological counseling

The patient also needs to undergo a series of tests including a thorough physical exam and blood test to ensure that he’s an appropriate candidate for the procedure. A consultation with an anesthesiologist is also recommended to determine how much anesthesia should be provided without increasing the risk of complications during the operation.

During the actual procedure, the patient is administered with general anesthesia and the rest of the body, except for the abdomen, is draped. The surgeon then proceeds by creating two to five small incisions in the abdominal area that provide the best access to the stomach.

A laparoscope, a long narrow tube equipped with a camera, is inserted into one of the incisions to provide a clear visual of the stomach and the nearby organs on a monitor.

Using small surgical instruments inserted through other incisions, the surgeon slowly removes a big portion of the stomach including the fundus, the upper part of the organ where the gases created during digestion and undigested food are stored, while keeping the pylorus, the lower part that promotes the emptying of stomach contents to the intestine, intact. The remaining part of the organ, which is still connected to the esophagus and the top of the small intestine, is then stapled, leaving the stomach looking like a banana.

Once the stomach size has been reduced, the instruments and the laparoscope are removed, and the incisions are stitched.

The entire procedure may take at least an hour and the patient may have to stay in the hospital for 2 to 3 days.

Before the patient is discharged from the hospital, the surgeon will check for any content leak and infection at the wound site. The doctor will also recommend a special liquid diet, which should be followed for a few weeks, to reduce stomach sensitivity.

Possible Risks and Complications

Laparoscopic surgeries have been associated with lower risks and complications because of small incisions and faster operation time. Nevertheless, sleeve gastrectomy may lead to:

  • Gallbladder issues
  • Reactions to anesthesia including breathing problems and allergies
  • Blood clots
  • Septicemia (sepsis)
  • Inflammation of the stomach lining (gastritis)
  • Ulceration of the stomach
  • Injury to the stomach and nearby organs
  • Bowel blockage due to stomach scarring

Sleeve gastrectomy is only an aid to weight loss, so for patients to continue losing weight or maintain a good one, they still have to adopt a healthy lifestyle. Otherwise, there’s still a good chance they will gain the weight they lost.


  • Brethauer SA, et al. (2009). Systematic review of sleeve gastrectomy as staging and primary bariatric procedure. Surgery for Obesity and Related Diseases, 5: 469-475.

  • Heber D, et al. (2010). Endocrine and nutritional management of the post-bariatric surgery patient: An Endocrine Society clinical practice guideline. Journal of Clinical Endocrinology and Metabolism, 95(11): 4823-4843. Available online:

Share This Information: