Overview of bariatric surgery
Bariatric surgery (weight-loss surgery) is surgery on the stomach and, with some types, the small intestine to treat severe (morbid) obesity, and today it is usually done by keyhole surgery. In keyhole (laparoscopic) surgery, the surgeon looks inside the abdomen using a special instrument with a camera (a laparoscope), and the operation is done through small cuts in the abdominal wall.
Severe obesity is often linked with serious, sometimes life-threatening conditions such as high blood pressure, diabetes or coronary heart disease. Non-surgical treatments include a low-calorie diet, medicines, behavioural therapy and exercise programmes. However, people with severe obesity often regain the weight they have lost within a few years, which is why surgery may be considered when these treatments have not been enough.
What causes severe obesity?
The causes are not yet fully understood, and many factors probably play a part. In people with obesity, the body's "set point" for stored energy is very high. This may be due to a low resting metabolic rate, a high calorie intake, or both. There is also scientific evidence of an inherited element. Severe obesity can develop when genetic, psychological, environmental, social and cultural influences combine and disturb the control of appetite and energy use. Because of this, obesity is not simply a question of willpower, and its treatment often needs more than one approach.
Types of operation
Established operations include the gastric band, the Roux-en-Y gastric bypass and malabsorptive procedures (biliopancreatic diversion, duodenal switch). They work in different ways: some mainly reduce how much the stomach can hold, while others also reduce how much the bowel absorbs.
- Gastric bypass: the stomach is divided and a small stomach pouch is formed. This is joined to the small intestine in a Y shape. The length of bowel that is bypassed can vary.
- Malabsorptive procedures: the stomach is made smaller and a large part of the small intestine is bypassed. As a result, the bowel absorbs fewer calories.
- Gastric band: a band about 1 cm wide is placed around the very top of the stomach. This creates a small upper pouch with a narrow opening into the rest of the stomach. With an adjustable band, this opening can be made narrower.
Which operation is chosen depends on the surgeon's assessment and on the patient's eating habits. You can read about another option on the gastric sleeve page.
Benefits of the keyhole technique
Compared with open surgery, the keyhole technique usually means a shorter hospital stay, a quicker return to work and smaller scars. It has been reported that conditions such as sleep apnoea, diabetes, high blood pressure and high cholesterol can improve after bariatric surgery. Because the keyhole operation is the same as the open operation, the long-term results are also comparable. If type 2 diabetes is your main concern, see also the diabetes surgery page.
Who is it for?
Surgery is considered only after a careful assessment, and the decision is based on several criteria rather than on weight alone. The criteria for selection include the following:
- There is no known metabolic or hormonal disorder causing the obesity.
- There are measurable health problems that would improve with weight loss, such as high blood pressure, diabetes, heart disease, breathing problems, lung disease, sleep apnoea or joint problems (osteoarthritis).
- You understand what the operation involves, including its possible risks and complications.
- You are willing to have medical follow-up for many years.
- Earlier treatment to lose weight has not worked.
Your willingness to keep to new eating and activity habits after the operation is as important as the medical criteria, because the operation is only one step in a longer treatment.
Risks
As with any major operation, complications can occur with bariatric surgery. These include:
- wound infection, the wound opening up, or an abscess
- a leak where the bowel has been rejoined
- a hole in the bowel (perforation) or a blockage of the bowel
- an ulcer at the join (marginal ulcer)
- lung problems
- blood clots in the legs
Later on, problems may develop that need a further operation, such as stretching of the pouch, persistent vomiting or heartburn. Rarely, the operation has to be reversed because of a complication. The risk of complications is higher with a repeat operation than with the first one.
After a gastric bypass, you may become short of vitamin B12, folate and iron. This can usually be prevented by taking the necessary vitamin and nutrient supplements. Another possible effect is dumping syndrome: after very sugary food and drinks, you may have abdominal pain, cramps, sweating and diarrhoea. Avoiding very sugary foods can help prevent this. After malabsorptive operations, a lack of protein can also occur alongside these deficiencies, and diarrhoea is common, depending on how much fat you eat.
Women who become pregnant after one of these operations need particularly close medical care. The risk of complications with the keyhole technique is no higher than with open surgery. After the operation, it also takes time to get used to the change in your body image.
Preparation
Preparation is a step-by-step process, and each step helps to make sure that the operation is suitable and as safe as possible for you. It usually includes:
- a thorough medical assessment to find out whether the operation is suitable for you
- further tests if needed, including advice from a dietitian
- if needed, a psychiatric or psychological assessment to judge how well you are likely to adjust to the changes after the operation
- depending on your health, an appointment with a heart (cardiology), lung (respiratory) or hormone (endocrinology) specialist
- your written consent, after the possible risks and benefits have been discussed with you
What happens
Before the procedure
In the last days before the operation, a few practical steps help to prepare your body:
- You start a liquid diet the day before the operation.
- You may be asked to empty your bowel completely before the operation.
- Shower the evening before or the morning of the operation.
- Do not eat or drink anything after midnight before the operation. The exception is medicines that your doctor has told you to take in the morning with a sip of water.
- Aspirin, blood-thinning and anti-inflammatory medicines (for example for arthritis) and vitamin E must be stopped for a while, from a few days to a week before the operation.
- Stop smoking and drinking alcohol, and arrange help for when you are back at home.
On the day
You are admitted to hospital the day before the operation, when a check-up is carried out. A drip (a thin tube in a vein) is put in so that you can be given medicines, and you will often be given medicines before the operation. You talk to the anaesthetist about the anaesthetic. The operation is done under general anaesthesia and takes a few hours.
In keyhole surgery, narrow tubes (trocars) are passed into the abdomen through small cuts. The laparoscope, connected to a small video camera, is passed through one of them, and the stomach and other organs are shown enlarged on a screen. Five to six cuts are needed for the special instruments. The abdomen is filled with carbon dioxide gas (CO₂), and the whole operation then takes place inside the abdomen. At the end, the gas is let out.
If keyhole surgery is not possible: in a very small number of patients, the keyhole method cannot be used. Reasons for open surgery, or for switching to open surgery, include heavy scar tissue from earlier abdominal operations, a poor view of the organs or bleeding during the operation. The surgeon makes this decision before or during the operation. Such a switch is not a complication: it is a decision made for your safety.
After the operation, you are looked after in the recovery room until you are fully awake, and then taken to your room.
After the procedure
- After keyhole surgery, you usually stay in hospital for 1 to 3 days.
- A tube may be passed through your nose; until it is removed, you may not be allowed to eat or drink.
- On the evening of the operation, you should sit in a chair rather than only lying in bed, and the next day you should get up and walk.
- Breathing exercises are part of your treatment. You will be given pain relief if you need it.
- On the first or second day after the operation, an X-ray of the stomach may be taken to check the stitches. If there is no leak or narrowing, you can drink fluids every hour, and the amount is increased step by step. Some surgeons also allow puréed food.
- After you leave hospital, you stay on liquid or puréed food for as long as your doctor advises.
Aftercare
At home, keep moving, go for walks and do light tasks, and carry on with your breathing exercises too. Pain after keyhole surgery is usually mild, although some patients still need pain relief.
Follow your doctor's instructions closely. Many people feel well after only a few days, but the body needs time to heal. You should be able to return to most usual activities, such as showering, driving, climbing stairs, working and light physical activity, after one to two weeks.
Any changes to your diet are discussed with you. A routine blood test is done 6 months after surgery.
When should you contact your doctor?
Contact your doctor straight away if you notice any of the following:
- a persistent temperature above 39 °C
- bleeding
- increasing swelling or pain in the abdomen
- persistent nausea or vomiting
- shivering (chills)
- a persistent cough or shortness of breath
- difficulty swallowing that does not settle within a few weeks
- fluid leaking from any of the cuts
- swelling of the calf or tenderness in the leg
If the result falls short
Some weight regain is common about two to five years after the operation. This is one reason why the new eating and activity habits need to be kept up in the long term. If weight loss does not happen, a further operation may be needed. The risk of complications is higher with such repeat operations than with the first operation, so the decision is made with the same care as the first time.