Sleeve gastrectomy

What is sleeve gastrectomy surgery?

A sleeve gastrectomy involves reducing the stomach size to about a quarter of its original size. It is divided vertically from the top to the bottom, leaving a banana shaped stomach, like a tube or sleeve.

The sleeve gastrectomy is usually performed laparoscopically (by keyhole surgery) and takes around 1 hour to perform. This typically involves making five small cuts on your tummy, to enable the camera and instruments necessary to perform the operation to be inserted. One of the cuts does need to be enlarged at the end of the operation to remove the part of the stomach that has been cut away. It is performed under general anaesthetic (you are asleep!) Your post-operative stay is usually 2 days, but you are allowed home when you are able to drink enough fluids, and your pain control is adequate to allow you to mobilise easily.

How does the sleeve gastrectomy work?

The sleeve gastrectomy works in a number of ways:

  • The smaller size of the residual stomach often restricts the amount or volume of food you can eat at one sitting.
  • The part of the stomach that is removed produces hormones that makes you feel hungry. One of these hormones is called ghrelin. If you don't have this hormone, you generally feel less hungry.
  • The rate of emptying from the stomach increases slightly and this also affects hormones produced in the small bowel that in turn influence the brain's control of eating.
  • Having said that, research has shown that how the body adapts to the presence of a sleeve gastrectomy is quite complicated. It is not simply a smaller stomach means you can eat less – indeed some people after a sleeve can eat quite a lot, especially if the food is liquid or soft in consistency.
  • If you take a lot of people who have had a sleeve gastrectomy, the average weight loss is around 60 % of their excess body weight at five years.  (Excess body weight is the difference between their actual weight and their ideal weight). Much of this weight will be lost in the first year, but this also varies between people.  Remember average is the half way point, half of people will lose more than 60 % of excess body weight, but that also means half will lose less than that.  All patients have their ‘target’ weight, but we gain most health improvements from the first stone of weight that we lose and least benefit, although still some benefit, from the last stone in weight that we lose. 

Figure 1 - Part of the stomach that is removed in a sleeve gastrectomy

Alternatives to sleeve gastrectomy

It would be best to avoid surgery altogether. Making major lifestyle changes to include dieting, healthy food choices and regular movement and exercise will be required after surgery anyway, and many people find that these things alone help them to lose weight without the need to undergo an operation. Others find that the addition of prescribed weight loss drugs provides all the help they need to get their weight down.

If these things don't help, or the effects don't last, it is reasonable to consider weight loss surgery, at which point the major consideration becomes which operation is best for you. Apart from the gastric sleeve, current surgical options include the gastric bypass, gastric band, and the gastric balloon.

Benefits of sleeve gastrectomy

Sleeve gastrectomy surgery is a relatively safe operation, and appears to have fewer risks and complications than gastric bypass surgery. On the other hand, when compared to the gastric band, the sleeve gastrectomy is a more invasive and riskier procedure but produces better weight loss results in most people.

For most patients who have sleeve gastrectomy surgery, the benefits in terms of losing weight are much greater than the risks. In particular, most patients with recently diagnosed diabetes mellitus (less than 5 years) can be cured of their diabetes with a sleeve gastrectomy. This may all happen within a few weeks of surgery, well before any significant weight loss has occurred. 

Risks of sleeve gastrectomy

Performing a sleeve gastrectomy involves an operation. There are thus the risks of the general anaesthetic, and there are the risks of the operation itself.

Modern anaesthetics are very safe, but being overweight does add a slight risk when having a general anaesthetic, and if for example you have other illnesses such as diabetes or heart disease then the anaesthetic risk is a little higher. At Weight Loss Surgery Scotland you will undergo a careful preoperative assessment where any potential risk factors are identified. Other specialists can be called in for opinions if required, and the consultant anaesthetists will meet you to discuss your anaesthetic beforehand. The hospital operating and anaesthetic facilities are state-of-the-art and all precautions are taken to reduce the risks.

A sleeve gastrectomy does involve removing part of your stomach so there will be a staple line where the stomach is cut. This staple line can leak. This is a serious complication and can require urgent, further surgery to correct. Damage to your stomach, intestines or liver is possible during the operation and bleeding or perforation of the stomach or bowels may be the result. Bleeding is not usually too much of a problem as long as it is recognised and fixed promptly. The need for a blood transfusion as a result of a sleeve gastrectomy is highly unlikely. Similarly, perforation of the stomach or bowels is not usually of major concern if the perforation is recognised and fixed.

The other main risk of surgery is blood clots. This can happen to anyone having any operation, not just a weight loss surgery operation. Every attempt is made by the Weight Loss Surgery Scotland team to minimise this risk around the time of your operation. We do this by using injections to thin the blood, as well as special stockings and calf pumps during the procedure. Getting you up out of bed and moving as quickly as possible after the operation is also important to keep the blood circulating in your legs.

Occasionally, the narrow sleeve gastrectomy can cause two problems.  In the first few weeks to months, sometimes the stomach does not empty well, and you find it hard to eat more normal, solid food.  This nearly always gets better by six months.  And some people can develop gastric reflux after surgery.  Again, this is usually mild in terms of severity of symptoms, and can be treated with tablets. 

Long term complications of the sleeve gastrectomy operation

Stomach dilation
If you regularly overeat into the small stomach remnant, it will stretch up and get bigger. This will mean you can eat bigger meals and thus lose less weight, or indeed put weight on. Sometimes, if picked up early, more careful eating behaviour can reverse this

Vitamin and other nutrient deficiencies
These are unusual as your intestines are still normal.  However, as you will be generally eating less, we recommend that you take a multivitamin supplement (including iron and calcium) every day anyway, to prevent any future problems.


Gallstones are common in the UK. Patients who lose weight are more likely to develop gallstones. In many patients, these gallstones cause no symptoms, and you are not aware you have them.  But sometimes they can cause inflammation in the gallbladder.  If this happens, you may require an operation to remove your gallbladder along with the stones at some point after your sleeve gastrectomy if they cause symptoms. 

Is my sleeve gastrectomy for life?

You should consider the sleeve gastrectomy as an operation for life.  Occasionally, your weight loss may not be sufficient by a sleeve gastrectomy alone, and further surgery, to incorporate a gastric bypass may be necessary.

How you and food interact remains a key part of you both losing weight and keeping your weight steady in the long term.  There is no bariatric surgery that allows you to eat what you want and lose weight. Establishing good eating patterns and making right food decisions is important for you to get the most from your surgery.  That is why follow up after your surgery is vital.  A one year follow up with our team is included with our inclusive care price.  You should make use of these appointments to help you get the best result from your gastric bypass. 

Will you keep me under review?

Yes, we will follow you closely over the post-operative period but once you have recovered from your surgery, an annual check up is often all that is necessary. This would include doing some blood tests to look for early signs of nutrient deficiencies. You will be able to eat most foods with time. Some foods will pass through the bowel very quickly, and trial and error will help you avoid these. However, we recommend that you do take multivitamin tablets (which often contain other important things like iron and calcium) to minimise the risk of deficiencies. Such follow up can often be arranged with your GP and does not require you to return to see your hospital specialist.

More detailed information here.