Overview of diabetes surgery
Diabetes surgery, also called metabolic surgery, is a surgical treatment for type 2 diabetes that works through changes to the stomach and small intestine, and it has been part of the treatment recommendations since early 2016. To understand why surgery can play a part, it helps to look first at the disease itself. Diabetes is not simply high blood sugar. It is a metabolic disease and a serious health problem. Blood sugar that stays high over time can lead to many complications, from sight loss and amputations to heart attacks and kidney disease.
Type 1 and type 2 diabetes
There are two forms. Type 1 diabetes mainly affects younger people and has a genetic basis. Type 2 diabetes develops in adulthood and is linked with excess weight and lack of physical activity. Around 90% of people with diabetes have type 2 diabetes.
Type 2 diabetes is treated with various medicines. If these do not control blood sugar well enough, insulin injections are used. Surgical treatments, known as diabetes surgery or metabolic surgery, are a further option in the treatment recommendations, mainly for people whose blood sugar remains poorly controlled.
How does metabolic surgery work?
In people who had operations for obesity, it was seen that their diabetes often improved as well as their weight. One important factor is the reduction in body fat, which is one of the main causes of type 2 diabetes.
Later, attention turned to operations on the small intestine, which plays an important part in controlling insulin. Hormones such as GLP-1, made in the last section of the small intestine, and GIP, from the upper small intestine, increase the release and effect of insulin. They also slow the emptying of the stomach and so help you feel full. This is the principle behind operations that do not work through weight loss alone but are designed to increase the release of these gut hormones. They are called metabolic surgery.
Who is it for?
The surgical treatment included in the guidelines is mainly considered for people with type 2 diabetes. In particular, it is considered for people with type 2 diabetes whose blood sugar cannot be controlled well enough with medicines and insulin, and who need more and more insulin and medicines over time. It may also be considered if you have a BMI above 30 with type 2 diabetes or severe metabolic problems. It is not a treatment for type 1 diabetes, which has a different cause.
Choosing the operation
Options include the gastric sleeve (sleeve gastrectomy), the gastric bypass, the duodenal switch, SADI-S, the partition technique and ileal interposition. The operation is decided on together by the patient and the surgeon. The aim is to choose an effective operation that changes the body's natural functions as little as possible.
The degree of obesity is important here. Based on BMI (body mass index), there are three classes:
| Class | BMI |
|---|---|
| Class 1 obesity | 30 to 35 kg/m² |
| Class 2 obesity | 35 to 40 kg/m² |
| Class 3 obesity | 40 kg/m² and above |
If the diabetes is caused by excess weight alone, as is often the case in class 3 obesity, a gastric sleeve or a similar operation may be enough. In class 1 and class 2 obesity, operations such as the partition technique or SADI-S are more likely to be considered, because in these cases the effect on gut hormones matters more than weight loss alone.
Risks
Diabetes surgery is an operation on the abdomen, and it carries the general risks of any such operation: bleeding, infection of a wound or inside the abdomen, reactions to the anaesthetic, blood clots in the legs and a leak where the stomach or bowel has been joined or closed. The more specific risks depend on the type of operation chosen. For example, after operations that bypass part of the small intestine, such as the gastric bypass, you may become short of vitamins and minerals such as vitamin B12, iron and folate, so supplements are needed.
Because blood sugar can change after the operation, your diabetes medicines and insulin also need to be checked and adjusted. This is one reason why follow-up by a hormone specialist (endocrinologist) is part of the treatment. Your surgeon will explain the risks of the operation planned for you before you give your consent.
Preparation
Before the operation, you will have a thorough medical assessment, including a review of how your diabetes has been treated so far and how well your blood sugar is controlled. Depending on your health, you may also be seen by a hormone specialist (endocrinologist), a dietitian and other specialists, such as a heart or lung specialist.
All your medicines, including your diabetes medicines and insulin, are reviewed with you before the operation, and you will be told exactly which ones to take, change or stop, and when. Blood-thinning medicines may also need to be stopped for a while. You will be asked not to eat or drink for a set time before the operation. If you smoke or drink alcohol, you will be advised to stop. Finally, the possible risks and benefits are discussed with you and you give your written consent.
What happens
On the day
Operations to treat diabetes are done by keyhole (laparoscopic) surgery, under general anaesthesia. The surgeon works through small cuts in the abdomen, using special instruments and a camera that shows an enlarged image on a screen. Open surgery is used only when necessary. Keyhole surgery means less pain after the operation, a quicker return to work and smaller scars.
After the procedure
You may need to stay in hospital for 3 to 4 days. During this time your blood sugar is monitored closely, you are encouraged to get up and walk, and your diet is started with fluids and built up step by step, as your team advises.
Aftercare
It is important that diabetes surgery is carried out in an experienced centre that has an obesity centre and can provide follow-up by a hormone specialist (endocrinologist). After the operation, your blood sugar and your need for medicines are checked, your treatment is adjusted as things change, and a routine blood test check is done at 6 months. You will also receive advice on eating and, depending on the operation, on the vitamin and mineral supplements you need.
When should you contact your doctor?
Contact your doctor or the hospital straight away if, after you go home, you have:
- a high temperature or shivering (chills)
- increasing pain or swelling in the abdomen
- nausea or vomiting that does not stop
- blood sugar readings that are much higher or lower than you have been told to expect
- redness, swelling or fluid leaking from any of the cuts
- shortness of breath or swelling of the calf