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Go deeper in detail on the gastric sleeve

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About the procedure

How the sleeve works

Your eligibility for sleeve surgery

About the procedure

Before surgery

We will ask you to follow a pre-operative diet before your procedure. This will usually be for 1 week but could be longer depending on your BMI.

After booking your procedure you will be invited to the hospital for a nurse pre-assessment appointment and wat that appointment we’ll take pre-op bloods and screen you for MRSA. You will also receive a call from the Healthier Weight clinical team to make sure you are fully prepared for your surgery. During this period you will also be receiving written information from us. this is designed to help you prepare for life after your surgery and to encourage you to plan for the new diet and eating habits that will help you be successful. It is important you make time to read and understand these.

The day of surgery

On the day of your surgery you will be admitted to the hospital and shown to your private room. Admission is normally before 0900.

You will usually meet the anaesthetist and surgeon before being taken to theatre and you will need to sign a consent form that the surgeon will explain to you.

Your surgery itself will normally take about 1 hour, usually a little less, but sometimes a little more.

The procedure involves the surgeon making 5 incision in the abdomen. This is keyhole (laparoscopic) surgery. The incisions are horizontal and into these small tubes are placed. Into those tubes your surgeon will put the instruments needed to complete your procedure.

The incisions are of the following sizes;

  • 1 x 15mm
  • 1 x 12mm
  • 1 x 10mm
  • 2 x 5mm


The larger incision is for the camera and the others are used for clamps (to retract the liver) and for the handheld instruments the surgeon will use to disect the tissue around the stomach and to cut and staple the stomach.

The sleeve itself is done using a ‘gun’. The gun is used to cut and staple the stomach. On each ‘fire’ of the ‘gun’ the stomach is cut and two rows of staples either side of the incision are made. This ‘firing’ process is repeated between 5 and 7 times, depending on the length of the stomach, until the stomach has been cut along its full length and 80% of it can be removed.

You are left with a stomach that is about the size of a fountain pen. 

After surgery

After your surgery you will go back to your room and you will be observed by the ward team on a regular basis. You will not routinely need care in an HDU unit but your hospital will have that facility should it be needed.

You will be visited by your surgeon and he will decide upon your discharge time based on how well you are recovering.

Although many patients are well enough to go home the day after surgery we prefer to have patients stay for a second night after their surgery so we can observe them and be as confident as possible that there is not a bleed or a staple line leak. It’s better to identify and treat complications before you go home rather than re-admit you at a later date.

The two-night hospital stay is an important safety feature of the Healthier Weight package.

If you have more questions, please see our FAQs

How the sleeve works

Although we have been doing weight loss surgery for over 40 years there is a still a lot that we don’t know about how the procedures work. In the case of the sleeve we know that there are three features that work in combination but we don’t know exactly how much each individual part contributes.

At a high level we can say that the combination of restriction (a smaller stomach) and changes to the gut hormones are the cause.

When we look more closely, there are three effects that we know about in relation to the change in gut hormones. 

  1. Ghrelin – we know that when the sleeve is done the amount of ghrelin produced by the body reduces.
  2. Bile acid metabolism – we also know that there are changes in the way that body metabolises bile acid
  3. Gut micro biome – Probably the biggest factor, and the one we currently know least about, is a change in the gut micro biome – changes to the bacteria in the gut. 


The combination of these factors will both reduce and change the appetite of the majority of patients so that about 90% are successful with sleeve surgery. Patients will often say that their taste for food changed immediately.

As with all weight loss surgery though, the key to long-term success is to embed the right diet and eating habits in the years immediately after surgery in order that you can sustain those behaviours long term when we know the immediate benefits of the procedures will start to diminish. So, aftercare and support are just as important for sleeve patients as they are for those who have the other weight loss procedures.

Your eligibility for sleeve surgery

The eligibility criteria that apply in private healthcare are a little different than those that apply in the NHS.

The reason is that the NHS eligibility criteria that is set by NICE (the National Institute for health and Clinical Excellence) has to balance the public health benefit with what the state can afford. 

In the private sector we are not faced with the same price restraints as patients are paying for their own procedure. This means that we can take decisions based purely on the available scientific data. For that reason we will generally consider patients with lower BMI than would be the case for the NHS.

The NICE guidelines state that patients will be eligible for weight loss surgery if they have a BMI above 40 or above 35 with at last one major co-morbidity. In addition patients will ned to follow and ‘pass’ a 6 – 12 month weight loss programme before they will be considered eligible for surgery. There will then usually be a waiting list.

The reality is that very few NHS Trusts apply these criteria and you may have read in the press that Trusts are applying their own, much tighter, selection criteria. This is because they do not have the resources needed to apply the NICE guidelines.

Some Trusts are limiting surgery to patients with a BMI over 50, to diabetics and/or to patients who don’t smoke.

At Healthier Weight, we generally consider sleeve surgery for patients with a BMI of 35 and above. You will need to have tried and failed with diets as a way to manage your weight and your weight will need to be having a negative effect on your every day life.

If you are of Asian ethnicity and/or you are a Type 2 diabetic we would consider surgery at a lower BMI. We will explain the eligibility criteria in more detail at your face to face consultation.

The risks of sleeve surgery

Although we will take all reasonable steps to eradicate the risk of complication, no matter how good the clinical team complications will occur from time to time. All patients must be ready to accept this risk before proceeding. Follow the link to read about sleeve complications

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*Weight loss surgery results and benefits vary and are different for each individual. As such, Healthier Weight cannot guarantee specific weight loss goals.