Need to know - obesity surgery
Upper GI surgeon Professor John Baxter answers GP Dr Linden Ruckert’s questions on the different types of surgery for obesity, which patients might be eligible and how to follow up.
Upper GI surgeon Professor John Baxter answers GP Dr Linden Ruckert's questions on the different types of surgery for obesity, which patients might be eligible and how to follow up.
1. Who is suitable for obesity surgery and what criteria or assessment will they have to fulfil to get funding on the NHS? Are there any age limits?
UK bariatric surgeons follow NICE guidance on which patients are eligible for surgery for weight reduction. In general, the BMI needs to be greater than 40kg/m2 but this can be lowered to 35kg/m2 if the patient has severe co-morbidities treatable by weight loss, such as difficult-to-control diabetes, or severe joint pain.
Most surgeons are reluctant to operate on patients under the age of 18, although there is a trend to reduce this threshold, as suggested in the latest review of NICE guidelines. Upper age limits are relative and depend on co-morbidities. Most surgeons would operate on a suitable patient even up to 65 years of age.
Unfortunately, most funders of bariatric surgery have ignored the NICE guidelines for obesity surgery and raised the threshold for obtaining funding. As a result, obtaining surgery on the NHS is currently a lottery and is very much a postcode exercise. The under-provision of this type of surgery is another unmet need of the NHS.
2. What are the main operations available in the UK?
All surgical procedures for weight loss are available in the UK, but some surgeons carry out only one or two types of surgery, while others offer more choices. It is still a matter of conjecture as to what is the best operation in any given circumstance, and the final decision is usually up to the individual surgeon and their patient.
About half of the operations performed in the UK are restrictive – usually gastric banding – and the other half are some form of gastric bypass. Further information about these procedures is easily obtained on the internet. The sites of the British Obesity Surgery Patients Association and Weight Loss Surgery Info are especially helpful . Gastric banding appeals to many patients as it is a relatively low-risk procedure but it does have a 10-20% long-term failure rate, especially in patients who are poorly selected.
Rationing of NHS bariatric surgery resources has forced many patients to go overseas where the prices are often cheaper than in the UK. Patients who go overseas for their surgery can obtain any operation, although the most prevalent procedure is gastric banding. Follow-up after surgery overseas can be problematic, although the NHS should take patients over if complications occur.
The more usual situation is being asked to provide ongoing care for patients who have been operated on overseas. The NHS is not bound to manage these patients as they have opted out of the NHS, so they must ensure that a package of postoperative care is available, which many overseas surgeons can arrange – although this is often limited and expensive.
Patients occasionally transfer their care privately to a UK bariatric surgeon, although many are reluctant to take these patients on.
3. Which operation is suitable for which patient?
There is a slowly emerging consensus, although not agreed by all, that restrictive surgery (gastric band or a sleeve gastrectomy) may be suitable for the patient who is not too large, eats a relatively healthy diet but simply eats too much (a volume eater). The choice between these two procedures depends on surgeon and patient preference.
Patients who are either very large, have diabetes or who eat large quantities of sweet foods may be better suited to a gastric bypass as a one-stage or two-stage procedure. Other procedures, such as biliopancreatic diversion – with or without a duodenal switch – are usually reserved for very large or older patients.
The patient must have a thorough understanding of the proposed surgery, and be given extensive counselling. Most operations are performed laparoscopically, although revisional operations and very large patients may require open surgery. This type of surgery should only be done in hospitals with good ITU facilities, which are sometimes needed by these patients.
4. What would you tell a patient before consenting them for surgery?
The patient needs to be informed about the potential complications of any surgery, such as bleeding, infection, deep vein thrombosis and pulmonary embolus.
Other complications depend on the type of surgery being performed. More complex procedures such as gastric bypass carry a higher morbidity and mortality than simpler procedures such as gastric banding.
Patients are warned that there is an overall perioperative mortality of around 1%, although this varies according to age, size and the number of co-morbidities. Bariatric surgery has remarkably low mortality given the difficult nature of the surgery and the co-morbidities that patients often have.
When a patient is referred to a bariatric service, they usually have to undergo a strict programme of education.
It is important that they are seen by a multidisciplinary team, which must include – at a minimum – a bariatric surgeon, a physician with an interest in obesity, a dietitian/specialist nurse and an anaesthetist with a special interest in anaesthesia for obese patients. In many cases, a psychologist and other specialists may also be consulted.
5. What are the main short-term problems with surgery?
The immediate perioperative complications and recovery from surgery are the immediate concerns for most patients. The most feared perioperative complications are pulmonary embolus and leaks from anastomoses. Some bariatric surgeons keep their patients on extended treatment with subcutaneous heparin for a few months to prevent a pulmonary embolus.
After recovering from the operation, problems that may occur in the first year relate to the type of surgery performed. Gastric banding requires considerable adjustment to eating smaller portions, which some patients find difficult, and weight loss may be less than expected.
The ‘soft calorie' syndrome, in which patients cheat by consuming semi-liquid food that passes through the band more easily, is a not uncommon cause of weight regain after gastric banding.
After gastric bypass surgery, some patients have difficulty consuming the high-protein diet required to prevent long-term malnutrition. But operations generally work very well in the short term and patients are usually very happy because they are losing significant weight for the first time.
6. What are the long-term problems which need to be assessed in follow-up?
The main problem with long-term follow-up is the need to have a local bariatric team who can keep the patient on track. Patients who have had restrictive surgery need to have band adjustments at frequent intervals until the right amount of constriction is achieved. There also needs to be close dietetic follow-up to keep the patient eating healthily.
It is even more important to maintain close co-operation with the bariatric team after bypass surgery, to avoid long-term nutritional problems arising from vitamin and micronutrient deficiencies. Bariatric teams have clear protocols for follow-up after various surgical procedures.
If complications develop, it is preferable that the patient sees their original surgeon and team in order to put things right. One of the problems with overseas surgeons is the cost of follow-up and dealing with any complications that may develop.
7. What is the long-term weight loss after surgery?
First of all, some definitions: excess weight (EW) is the weight before surgery minus the ideal body weight (IBW). Typically, for a BMI of 50kg/m2 where the patient is exactly twice their IBW, the patient may have about 10 stones EW. Losing five stones would represent a 50% excess weight loss (EWL).
In general terms, bariatric surgery is considered successful if there is a greater than 50% EWL.
The results of surgery depend on the patient's starting weight, type of operation and length of follow-up. In broad terms, restrictive surgery – gastric banding and sleeve gastrectomy – results in 50-55% EWL after five years, while gastric bypass usually results in 60-65% EWL.
Biliopancreatic diversion results in 75-80% EWL.
Although weight loss is the primary objective of bariatric procedures, it could also be argued that resolution of comorbidities and improved quality of life might be equally important.
8. What are the other parameters, such as reversal of diabetes, which can improve with surgery?
Obesity surgery has been shown to reduce mortality in two recent studies. It has also shown spectacular results in reducing type 2 diabetes – especially after bypass surgery, where cure rates can be greater than 90%.
Nearly all other comorbidities, including high blood pressure, obstructive sleep apnoea, high lipid levels and chronic joint pain, are improved by successful weight loss following surgery.
Body image and self-esteem also improve and the patient is more likely to be employed.
Importantly, it has also been shown that patients who have obesity surgery cost the health service less over time because of the reduction in comorbidities.
9. Are there any unexpected risks that patients should be counselled about?
There should be very few unexpected risks as the consenting surgeon should have explained all the known risks for the type of operation planned for the patient. But unexpected and rare complications can sometimes occur and it is difficult to know where to draw the line when counselling patients.
In general terms, most of the procedures are straightforward and have good results, providing the patient fulfils their part of the contract. Attention to detail in the follow-up period is the key to a successful outcome.
10 (online only). Is surgery the main way forward in severe morbid obesity – or has the media just hijacked the issue and given undue emphasis to this treatment option?
Bariatric surgery is the only sustainable proven treatment for morbidly obese patients. Several studies comparing medical with surgical treatment have overwhelmingly favoured surgery.
Even though surgery takes a ‘target organ' approach and does little to change the underlying pathophysiology, there is increasing research favouring its use, particularly procedures that can be safely performed in high-volume units with minimal morbidity and mortality.
The problem is, as always, in a socialised healthcare system, getting enough resources to be able to deliver this treatment to patients who want it. Bariatric surgery rates are appallingly low in the UK because of ignorance and prejudice from both the medical profession and the public.
It is a national disgrace that the rates of surgery are not higher, particularly when surgery has been proven to save lives, improve quality of life and save the health service money.
Professor John Baxter is a consultant upper gastrointestinal surgeon and clinical director of surgery at Swansea NHS Trust – he is also president of the British Obesity Surgery Society
Competing interests: none declared
What I Will Do Now What I Will Do Now
Dr Ruckert considers the responses to her questions
• I will check exactly our local funding arrangements for obesity surgery. I am also not sure which operations are done by which surgeon in various central London hospitals, and I should find out. It is a pity that the potential costs of long-term medication for comorbidities are not offset against the cost of surgery.
• I will consider referring patients to the multidisciplinary team at an earlier age and lower
BMI for assessment if other measures have failed.
• If I know that patients are considering operations abroad, I will advise them of the need for, and potential problems in accessing, follow-up in the UK.