Gastric Sleeve Surgery

(Sleeve Gastrectomy)

gastric sleeve surgery

How Does Gastric Sleeve Surgery Work?

Gastric sleeve surgery (also known as sleeve gastrectomy) is currently the most popular weight-loss operation around the world. 75% of the stomach is permanently removed and seam-guarded, leaving a thin tube or sleeve. It works by reducing the amount of food you can eat.

The other part of the operation is removing the upper part of the stomach (the part that produces the hunger hormone, ghrelin). By removing this part of the stomach, your appetite will reduce and you will feel fuller sooner.

The sleeve also impacts the release of hormones that boost weight loss and, in some cases, helps improve obesity-related medical problems such as diabetes and high blood pressure. The procedure, which takes 45 to 60 minutes to complete, is undertaken laparoscopically (using small keyhole incisions) under a general anaesthetic. There is a small potential for conversion to open surgery (less than 0.1%).



*As with any surgical procedure, there are possible risks and complications, including bruising, pain & bleeding, infection, nausea & vomiting, oesophagitis (inflammation of the oesophagus) or gastritis (inflammation of the stomach), bowel rupture/leakage, scarring, stricture or narrowing of the sleeve so food can’t pass through, intolerance to certain foods, gastroesophageal reflux disease (GERD) with severe heartburn, dumping syndrome, internal injury to your organs during surgery and leaking from the staples, pulmonary embolism (clot to the lung), deep vein thrombosis and death. These are uncommon and we will do everything possible to prevent them from happening. One in ten patients may experience acid reflux symptoms and require PPI (anti-acid) tablets (though this would be expected to improve or resolve in most patients as the sleeve and eating habits mature over one to two years). The sleeve gastrectomy may also be associated with developing Barret’s oesophagus.

Patients may require plastic surgical procedures after weight loss has levelled off, to treat loose skin.

Patients may develop symptomatic gallstones after weight loss, which would require a laparoscopic cholecystectomy.

If you do not reach the expected weight loss after surgery, your surgeon can explain the alternative interventions or revisions available.

Please speak to your Tonic surgeon to discuss the risks in more detail and any concerns you may have.

Chanelle Hayes had a gastric sleeve with Tonic. Watch her inspiring story below.

Weight Loss Results

At twelve months, gastric sleeve patients can expect to lose approximately 70–75% of their excess weight (a term used to describe weight above a BMI of 25).

Typically, that’s 25–30% total body weight over a period of nine to twelve months.

Gastric sleeve surgery is considered a non-reversible procedure as we are removing a part of the stomach. This helps patients achieve long-term sustained weight loss.


To prepare for the sleeve gastrectomy, patients will have a consultation with their surgeon and will be assessed by the Tonic team, including the dietitian, psychotherapist and bariatric nurse specialists.

Patients will be asked to go on a liver-shrinking diet (800 calories a day), for around two weeks before surgery.

Recovery Time and Aftercare

The average post operative hospital stay from gastric sleeve surgery is one to two days, with an enhanced recovery programme.

Patients can expect to be up and walking within three hours of surgery, drinking the same day, and returning to work and normal activities within seven days.

After the operation, patients will be advised to go on a specialist diet to help with the healing process.

This involves a liquid diet for two weeks, a puréed diet for one to two weeks and eating soft, easy-to-chew foods for one to two weeks. The first follow-up appointment after the sleeve is usually six to eight weeks after the operation. In this session, the surgeon will advise on progress and ensure there are no immediate problems.

Patients will be eating smaller portion sizes and so they will need to take supplements to reduce the risk of vitamin and mineral deficiencies following surgery. Patients will require lifelong calcium (with vitamin D), iron and multivitamins, as well as three-monthly vitamin B12 injections. Blood tests are recommended every six to twelve months to ensure adequate supplementation. Alternatively, patients can take all-in-one supplements. (Tonic’s equivalent is VitMyLife.)

If you commit to the aftercare process, it will have a positive long-term impact on your weight loss journey and any weight-related medical problems you may have.

Read more about our premium five-year aftercare package at the bottom of this page.

Is Sleeve Gastrectomy Right for You?

If you have already tried adjusting your diet and exercise routine to lose weight and these measures have not been effective, you may qualify for a gastric sleeve. The sleeve gastrectomy is generally not advised for those with conditions such as acid reflux, Barrett’s oesophagus and oesophageal dysmotility.


Gastric Sleeve Surgery procedures are available in London, Derby, Manchester, Leeds, Luton, Birmingham, Nottingham and Leicester, with finance options available.