Gastric sleeve gastrectomy Singapore: What to know about it

Often, severely obese patients who do not successfully lose weight despite diet and lifestyle efforts opt to do bariatric surgery. 

Bariatric surgery refers to surgical procedures that remove or reduce the size of the stomach to treat obesity. Patients typically experience rapid weight loss after bariatric surgery. Gastric sleeve surgery or sleeve gastrectomy is a bariatric surgery option. 

What does it involve, how effective is it and are there any possible complications? This article will find out more.

What does gastric sleeve gastrectomy in Singapore involve?

Gastric sleeve gastrectomy is usually done as a minimally invasive procedure with a laparoscope. A laparoscope is a long, thin tube with a light, tiny camera and sometimes various instruments attached to it. It is inserted into your abdomen via several small incisions. 

During the surgery, the surgeon divides your stomach into two unequal parts — about 80 percent of the outer curved part of your stomach is cut away and removed. The remaining 20 percent are then sutured or stapled together, creating a banana-shaped stomach that’s about 20-25 percent of its original size. 

The entire procedure will take about an hour under general anaesthesia, which means you’ll be asleep during the surgery.

How does gastric sleeve gastrectomy work in Singapore?

Gastric sleeve gastrectomy helps in weight loss via two ways: 

  1. You eat less and feel full sooner as your stomach is significantly smaller. This means you consume fewer calories. 
  2. Ghrelin, a hormone in your stomach that’s associated with hunger, is removed so you won’t feel as hungry.

On average, patients lose about 60-70% of their excess weight over 6 months to a year. It is a gradual weight loss process that goes like this:

  • First 2 weeks: 5-10kg; most patients lose about 0.5kg or one pound a day
  • First 3 months: weight loss is about 35-45% 
  • First 6 months: weight loss is about 50-60% 
  • First year: weight loss is about 70% 

Most reach their lowest weight about 12-24 months after surgery. But all this weight loss will only be successful if you follow the diet and exercise plan recommended by your doctor, especially if you intend to keep the weight off long term. 

Additionally, patients with obesity-related diseases such as type 2 diabetes, high blood pressure and obstructive sleep apnea find that their conditions improve after gastric sleeve gastrectomy. This is all thanks to weight loss; keeping a healthy weight can improve your quality of life and enable you to perform daily activities with ease.

How is sleeve gastrectomy different from gastric bypass surgery?

In gastric bypass, the surgeon makes a small pouch out of your stomach and small intestine. This allows food to skip most of your stomach and head straight to the intestine, allowing the patient to eat less. 

Gastric sleeve gastrectomy is a good alternative for those who are too heavy for gastric bypass surgery; it is best for those with a BMI of at least 40. 

Other than that, gastric sleeve gastrectomy and gastric bypass surgery work through the same mechanism, which is for the patient to consume lesser calories to lose weight.

Who is suitable for agastric sleeve gastrectomy in Singapore?

Bariatric surgery including gastric sleeve gastrectomy should only be considered an option when the use of weight loss medication as well as attempts to change your diet and exercise habits do not work. 

Even so, you must meet certain criteria in order to be eligible for such a surgery. They are:

  • Extreme obesity with a BMI of 40 or higher 
  • Obesity with a BMI of 35 or higher with at least one obesity-related condition

Occasionally, gastric sleeve gastrectomy can be done even if you don’t meet the criteria for obesity but are still overweight, as long as you have a significant weight-related health condition.

Diet changes after the surgery

In order for the results of gastric sleeve gastrectomy to be successful, you have to adopt certain lifestyle changes. This includes eating a healthier diet and exercising regularly for the rest of your life. 

After the surgery, you’ll find that your appetite is smaller and you won’t feel as hungry anymore. This limits the number of calories you consume. Your doctor will also prescribe some multivitamins, supplements and a monthly B-12 shot to make up for nutritional deficiencies. 

Before and right after the surgery, your diet plan might look like this: 

  • Two weeks before surgery: No sugar, reduce carbohydrates, increase protein 
  • First week after surgery: Only clear liquids that are caffeine and carbonated free 
  • Next three weeks: Slowly add pureed food into your diet

Are there any risks?

While gastric sleeve gastrectomy is a relatively safe procedure, as with all major surgeries, it comes with its own risks and complications. 

They include:

  • Hemorrhage due to bleeding from the surgical wound 
  • Deep vein thrombosis due to blood clots forming in your vein 
  • Irregular heartbeat 
  • Pulmonary embolism 
  • Pneumonia 

Specific to the surgery, complications include:

Gastric leaks
Stomach fluids can leak out from the suture lines in your stomach

Vitamin deficiencies
There will be a section of your stomach removed that’s partly responsible for the absorption of vitamins. To avoid vitamin deficiencies, you must take supplements

This happens when part of your gastric sleeve closes, causing an obstruction in your stomach

Reshaping your stomach can result in heartburn, but this can be treated with medication

Large amount of excess skin
When you lose a significant amount of weight quickly, there’s bound to be excess skin. If it bothers you, the excess skin can be surgically removed, but you have to wait at least 18 months after the sleeve gastrectomy for your body to stabilise. 

Another thing to note also is that unlike other bariatric surgeries, sleeve gastrectomy is irreversible. Your stomach cannot go back to the way it was, so you should think carefully and consult with your doctor before deciding whether to go for the surgery.


  1. Brajcich, B. C., & Hungness, E. S. (2020). Sleeve Gastrectomy. JAMA, 324(9), 908–908.
  2. Eisenberg, D., Bellatorre, A., & Bellatorre, N. (2013). Sleeve Gastrectomy as a Stand-alone Bariatric Operation for Severe, Morbid, and Super Obesity. JSLS : Journal of the Society of Laparoendoscopic Surgeons, 17(1), 63.