Gastric Sleeve Surgery

On average, a person will lose 50-60 % of their excess body weight (the difference between their weight before the operation and their healthy weight) within a year with gastric sleeve surgery. However, the surgery won’t do all of the hard work for you. Although having gastric sleeve surgery should make sticking to your diet a little easier, you will still need to follow your diet plan very carefully.

Sleeve gastrectomy or gastric sleeve surgery is a type of weight-loss surgery where the size of your stomach is reduced by removing the lateral 2/3rds of the stomach (approx. 75-85%) with a stapling device, shaping the remaining stomach into a tube or ‘sleeve’ so that you can only eat small meals.

The gastric sleeve procedure takes one to two hours. The surgeon will usually be able to work laparoscopically, which means that you will only need small, keyhole incisions. You will need to have a general anaesthetic.

What are the alternatives?

Surgery should only be used for weight loss after you have tried losing weight by dieting and exercising. Your doctor might also recommend trying certain medicines before considering surgery. If you are sure about bariatric surgery, you have a few alternative procedures to consider. In addition to sleeve gastrectomy, it is possible to have a stomach band fitted or to undergo a gastric bypass operation.

How it Works?

Gastric sleeve surgery involves the removal of a large section of your stomach. Reducing the size of your stomach will restrict the amount you can eat. It will also reduce your appetite by decreasing the production of appetite stimulating hormones in your stomach.

The sleeve gastrectomy is usually performed as a laparoscopic procedure, through four or five keyhole incisions. The operation will take one to two hours and requires a general anaesthetic. A large part of your stomach will be removed. The remaining section will be shaped into a sleeve or tube about the size of a banana and sealed using staples. You will need to stay in hospital for two to three nights after the procedure and it will be two or three weeks before you are fully recovered.

Advantages of Gastric Sleeve Surgery

A sleeve gastrectomy can help you to lose weight by restricting the amount you can eat and reducing your appetite. Like a gastric bypass or band, gastric sleeve surgery restricts the amount of food that you can eat by reducing the size of your stomach so that you feel full faster. However, the removal of a large part of your stomach also reduces the amount of appetite stimulating hormones it is producing, which can help you to feel less hungry. Most people who follow the recommended diet will lose 50-60% of their excess weight after the gastric sleeve procedure.

Gastric sleeve surgery does not alter the route that food takes through your digestive system and the remaining part of the stomach retains its ability to start the digestive process, so you will still be able to digest and absorb food normally. Dumping syndrome is less common than with a gastric bypass, but there is still a chance that it could happen as the food will be passing through your small stomach sleeve faster than usual.

– During the laparoscopic sleeve gastrectomy the nerves of the stomach and pylorus are not altered, preserving the function of the stomach.

– The rest of the gastrointestinal tract anatomy is not altered, so the food ingested follows the normal course. This results in less chance of developing lack of vitamins and minerals and dumping syndrome.

– The procedure decreases significantly the hunger by removing the part of the stomach that produces the main stimulating hormones.

– Fewer clinic follow-ups than the laparoscopic stomach band, since there is no need for band size adjustments.

Benefits of Weight Loss - Gastric Sleeve Surgery


of Type II diabetics are cured


Average (mean) excess weight loss


of patients with hypertension reduce or stop medication


will have improvement in cholesterol levels


of patients with polycystic ovary syndrome have restored fertility


of patients with Liver Disease will have complete resolution


of patients who use a continuous positive airway pressure machine will be able to stop

Gastric Sleeve Surgery - Risks & Complications

What are the risks?

Gastric sleeve surgery is generally safe, but there are always risks when you are having an operation. You will need to discuss these risks with your doctor before deciding if the procedure is right for you.

Side Effects

Certain side effects can happen after gastric sleeve surgery. Side effects will usually only be temporary and they are generally mild. The most frequent effects are soreness or some slight swelling round the incisions. Some people experience discomfort after eating in the first days after the operation. This feeling should go away once you heal, as long as you don’t overeat.


More serious complications can also happen when you have gastric sleeve surgery. This is when problems occur during or after the operation. Such problems are much less common than the milder side effects. Most people will not experience any serious complications from this surgery.

One potential risk of having the procedure is that you will need to be put under a general anaesthetic. Some people can have a bad reaction to the anaesthetic. Other potential complications associated with surgery include heavy bleeding and blood clots. The chance of surgical complications is low, but they are increased by conditions such as high blood pressure.

Some of the complications you may get after sleeve gastrectomy operation are listed here:
Although antibiotics can help prevent post-surgical infections, there is still a chance that you will develop one and require further treatment
Damage to your organs
Although the risk is low with an experienced surgeon, it is possible other organs in your abdomen could be damaged. Another procedure could be required to set it right.
Staple line leak
During a sleeve gastrectomy, your stomach will be sealed with surgical staples. If these start to leak while you are recovering from surgery, you may need another operation to seal your stomach.
Sleeve stricture
Sometimes the sleeve-shaped stomach can get narrower after surgery or an ulcer may form in it. More surgery or a procedure called an endoscopy might be necessary to fix the problem.
Some people get gallstones when they lose a lot of weight quickly.
Failure to achieve weight loss
A sleeve gastrectomy will help you to lose weight, but it doesn’t guarantee you’ll reach your goal. Some people don’t manage to get rid of their excess weight even after surgery.

There is a chance your surgeon may need to convert your keyhole procedure to open surgery. This means making a bigger cut on your abdomen. This is only done if it’s impossible to complete the operation safely using the keyhole technique.

The chance of complications during or after the procedure will vary between individuals. Your surgeon will be able to provide personalised advice on the risks of weight loss surgery. In general, about 5% of people will experience some complications when having a sleeve gastrectomy. The chance of experiencing fatal complications during surgery is 0.2%.

Gastric Sleeve Surgery - Pre/Post Surgery Information

Gastric sleeve surgery requires a long term approach for successful weight loss. Your journey towards your target weight will begin before the operation, as you prepare for sleeve gastrectomy.

Preparing for Gastric Sleeve Surgery

A healthy diet and lifestyle will be essential for weight loss after surgery. Starting to make these changes before the operation can make recovery easier. Eating a calorie controlled diet is especially important in the last few weeks as it can reduce the size of your liver and lower the risk of surgical complications. If you smoke, you should try to give up before the procedure as it could affect your healing.

As it gets closer to the day of your operation, you should:

  • Stock up on healthy foods and freeze some liquid meals for your return home.
  • Arrange at least 2-3 weeks off work and ask for help around the home. You may need assistance with childcare, housework and other everyday tasks.
  • Get your hospital bag ready, with plenty of comfortable clothing, a dressing gown and slippers, your essential toiletries, and some books, magazines or other entertainment to keep you occupied.
  • Make sure you have a comfortable place to rest when you get back. Lots of cushions, plenty of entertainment, and a fan or heater will help.

On the night before surgery, you will need to stop eating and drinking to prevent complications during the procedure.

Recovering from Gastric Sleeve Surgery

You will need plenty of rest when you get home, but you should gradually be able to return to your normal routine over the next 2-3 weeks. However, you should avoid any heavy lifting or very strenuous activities for a couple of months.

The surgical wounds should heal in about a week. The dressings can then come off. You should look out for any signs of complications, such as swelling, pus or inflammation. About 5% of patients will experience some kind of problem after gastric sleeve surgery, but serious complications are rare.

You will have follow up appointments to check on your recovery, but you should contact your doctor if you notice anything unusual or you are experiencing severe discomfort.


When you wake up in the recovery room after gastric sleeve surgery, you will probably feel a bit sore and drowsy. Your memory may be a hazy for a while. You will have dressings over the surgical wounds in your abdomen and there may be tubes draining away excess fluid. You might also have a catheter.

The nurses will offer you something to drink and monitor your condition as you recover. You should soon be able to get out of bed and move around a little. You will usually need to spend 2-3 days in hospital for gastric sleeve surgery. You should arrange for someone to pick you up from the hospital as you won’t be able to drive until your surgical wounds have healed.

Eating After Gastric Sleeve Surgery

Your doctor will ensure that you have a personalised diet after gastric sleeve surgery. You will be on a liquid-only diet for the first few weeks. You can then begin to introduce some soft, moist foods that will be easy to digest. It will be about 4-6 weeks before you can start eating solids. Certain foods, such as white bread, rice, high fibre vegetables and chewy meat may need to be reintroduced more slowly as they are more difficult to digest.

The sleeve gastrectomy should help you to stick to your diet by restricting the amount you can eat and reducing your appetite. However, you may experience some acid reflux, nausea or vomiting as your body adjusts to the sleeve gastrectomy. You should soon begin to lose weight and notice an improvement in your health, as long as you follow your diet.


Gastric sleeve surgery could be a good option if you have tried and failed to lose weight through diet and exercise. You could be a suitable candidate if you have a BMI over 40 or a BMI of at least 35 and an obesity-linked condition such as type 2 diabetes. You will also need to be physically fit for surgery and committed to making long term changes to your lifestyle.

Gastric sleeve surgery reduces the size of your stomach by up to 85%. The remaining part of your stomach will be stapled into a small tube or sleeve, about the size of a banana. You won’t be able to eat as much after the procedure and you should feel less hungry as you will be producing less of the hormones that stimulate your appetite.

The amount of weight you lose will depend on how well you stick to your diet after surgery. The average patient will lose 50-60% of their excess weight within two years, but you could lose more in the long term.

If you have a condition that is linked to your weight, you may see an improvement after surgery as you begin to lose weight. Gastric sleeve surgery is particularly effective for type 2 diabetics, which can sometimes disappear completely after the procedure. Your doctors will monitor your condition and make changes to your treatment if necessary.

Common side effects after a sleeve gastrectomy include soreness and slight swelling around the surgical wounds. You may experience some nausea or discomfort after eating at first. You could also have dumping syndrome if you eat too much sugar. If you suffer from acid reflux, it could get worse after gastric sleeve surgery because your stomach will be smaller.

All medical procedures come with a small risk of complications. Approximately 5% of people who have gastric sleeve surgery will have complications of some kind. Although these are usually relatively mild and easy to treat, they can sometimes be more serious. The complications are fatal in 0.2% of people.

Potential risks of sleeve gastrectomy include:

  • Post-operative infections
  • Leaks where your stomach has been stapled together
  • Narrowing or stricture of the stomach sleeve after surgery
  • Damage to your organs during the operation
  • A bad reaction to the anaesthetic
  • Heavy bleeding or blood clots
  • Gallstones

Gastric sleeve surgery is not reversible because part of your stomach will be removed. However, it is possible for the remaining part of your stomach to stretch in time, if you overeat. You will need to follow your diet in order to prevent this from happening.

You should be able to eat a normal range of foods within a few months of your sleeve gastrectomy. However, you should avoid foods that are high in fat and sugar as these will prevent you from losing weight. It is best to choose meals that include textured, filling foods that will satisfy your stomach. Liquids and soft foods will pass through your stomach too quickly, so you won’t feel full even when you’ve had enough.

You should be able to get all the nutrition you need from your food after a sleeve gastrectomy. Your doctor can provide advice on eating well after surgery and may recommend a supplement if you are finding it difficult to get enough of certain vitamins.

Clinic Locations

Harley Street, London

Harley Street,

The London Independent Hospital

Stepney Green,
E1 4NL

Spire London East Hospital


The Holly Hospital

Buckhurst Hill,

Rivers Hospital

CM21 0HH

Nuffield Health

CM15 8EH

Before/After Stories

“Since having the operation I can now go into any shop and buy the clothes I love, rather than the clothes that just fit my size. I could never have imagined buying a size 10 before. The operation has not effected my social life in any way.”
“My experience of Mr. Agrawal was very positive, he was very positive about doing the surgery, he was very relaxed and I was very confident in him. I would definitely recommend Mr. Agrawal.”
“Mr. Agrawal, that’s a lot of fun, absolute brilliant guy.”
“I was a bit scared going to see him, I’d brought my husband with me, in case I forgot what he said. Having someone beside me was very useful. He explained the procedures and types of procedure, and which one I could go for. He was very down to earth and straight forward, I found it very pleasant”


As seen on TV