Bariatric Surgery (Obesity Surgery)

Essentials

• Bariatric surgery may be considered for a severely overweight patient to support lifestyle changes and to improve the permanence of the results of weight reduction. Criteria include:
  • Body Mass Index (BMI) exceeding 40 kg/m²
  • BMI exceeding 35 kg/m² plus a related disease or a risk factor for such a disease
  • BMI 30-35 kg/m² in a person with type 2 diabetes, if conservative treatment of obesity and diabetes has not produced adequate results
• The patient must have undergone about 6 months of conservative treatment leading to lifestyle changes and to a weight loss of about 5%. Such treatment should primarily be provided in primary health care before referring the patient to specialized care.
• The long-term results of bariatric surgery are usually significantly better than those achieved with conventional management.
• The greatest benefits offered by bariatric surgery include a reduction in obesity-related diseases and easier management of such diseases, as well as perceived improvement in the quality of life.
• The most common methods are gastric bypass and sleeve gastrectomy.
• After bariatric surgery, all patients need permanent vitamin and trace element replacement.

Criteria for surgery

• The patient's age is between 18 and 65 years. In exceptional cases, surgery may be considered in patients of 13-17 years.
• Prior to surgery, the patient has participated successfully (weight loss about 5%) in a weight management programme offered by a health care unit (group, individual or internet-based 6-month treatment) but the result has not been sufficient in relation to the weight loss target or has not been maintained after treatment.
• It is essential that the patient has been shown to be able to make lifestyle changes and that the results were not achieved with a very low calorie (VLCD) diet, alone.
• BMI (calculator Bmi)
  • exceeding 40 kg/m²
  • exceeding 35 kg/m² in a patient with a related disease or a risk factor for such a disease, such as
    • type 2 diabetes or its preliminary stage
    • sleep apnoea requiring CPAP therapy
    • hypertension requiring medication
    • osteoarthritis of weight-bearing joints (or other severe disease of the musculoskeletal system)
    • dyslipidaemia
    • asthma
    • polycystic ovary syndrome (PCOS)
    • infertility
  • 30-35 kg/m² in a person with type 2 diabetes, if conservative treatment of obesity and diabetes has not produced adequate results.
• The patient must be able to change his/her eating habits as required by the surgery (small portions evenly spaced and slow eating), to commit to permanent vitamin and trace element replacement and to adapt mentally to the new, altered self-image. The patient must have a realistic understanding of the impacts of the procedure.
• General suitability for surgery

Contraindications

• Severe eating disorder requiring treatment, in which case the patient should be referred for psychiatric consultation
• Excessive use of alcohol (see Recognition of Alcohol and Drug Abuse Brief Interventions for Risky Use of Alcohol, AUDIT test Audit)
• Severe mental health problem requiring treatment, in which case the patient should be referred for psychiatric consultation
• Severe systemic diseases (e.g. liver cirrhosis or serious heart disease)
• Disease affecting the upper digestive tract and requiring follow-up by endoscopies
• Need for continuous use of non-steroidal anti-inflammatory drugs
• The patient has been unable to lose any weight, even temporarily, with conservative treatment.

Surgical options

• Bariatric surgery is performed by laparoscopy. Most patients can be discharged 1-2 days after surgery.
• The most common surgical methods are gastric bypass and sleeve gastrectomy.

Preparation for surgery

• The suitability of an individual patient for a weight-loss procedure is usually assessed by an endocrinologist, internist or multi-specialist team familiar with the treatment of obesity.
• As needed, a psychiatric consultation may be carried out, e.g. if the patient has a psychiatric disorder and the patient's ability to commit to the post-operative changes in eating and to the follow-up is uncertain.
• Gastroscopy, ultrasound examination of the liver and assessment of sleep apnoea should be performed as considered necessary.
• Helicobacter pylori testing should be performed during the gastroscopy or using a stool sample.
  • If Helicobacter pylori infection is detected, eradication therapy should be performed. The success of the therapy should be checked.
• Smoking should be stopped no later than 1 month before surgery because it will slow down the healing of GI sutures and increase surgical risks.
• 2-6 weeks of a VLCD may be needed before surgery to decrease the size of the liver, as considered necessary by the surgeon.
• The decision as regards the most suitable surgery option is often made between the surgeon and the patient.

Effects of bariatric surgery Surgery for Morbid Obesity

• Bariatric surgery is usually significantly more effective than conventional management as regards long-term weight loss.
• Surgery will not prevent the patient from regaining weight. Therefore, permanent changes to dietary habits are needed to achieve permanent weight loss.
• Weight loss will usually continue for 1-2 years after surgery, whereafter weight gain tends to occur. This is associated with increased energy intake and reduced physical activity.
• The weight loss achieved with surgery reduces mortality to some extent.
• The greatest benefits include a reduction in obesity-related diseases, easier management of such diseases, and a perceived improvement in the quality of life.
• Bariatric surgery will reduce the need for antidiabetic medication in patients with type 2 diabetes for up to 5 years after surgery, during which time a significant share of patients with diabetes will remain normoglycaemic without medication.
• Bariatric surgery nearly always improves blood glucose control in patients with diabetes and reduces the need for insulin, even if complete remission would not be achieved. In addition, the risk of microvascular complications of diabetes is reduced.
• The weight loss following bariatric surgery often leads to normalisation of blood lipid values (reduction in plasma triglycerides and increase in HDL cholesterol), alleviation of sleep apnoea, reduced need for antihypertensive agents and asthma medication, and to improved mood.
• Fertility often improves in young women. The surgery reduces the risk of gestational diabetes, macrosomia, complications associated with blood pressure, and caesarean section but it may increase the risk of foetal growth retardation. Pregnancy is not recommended during rapid weight loss, i.e. within 1-2 years from surgery, and contraceptive precautions (using a hormonal IUD, for instance) must be taken during that period.

Complications

• Operative mortality is under 0.5%, but the figure is higher for severely obese and elderly patients.
• The most common complications of surgery are lung problems, deep infections, wound complications, venous thrombosis or pulmonary embolism and bleeding problems.
• In about 3% of cases, immediate repeat surgery is needed, usually due to bleeding or leaks in the suture lines.
• Various immediate surgical complications leading to delayed recovery will develop in about 10% of patients. The risk of intestinal obstruction is highest during the month following surgery.
• About 10% of patients will require surgical intervention at a later stage (for example, for dilatation of anastomotic stenosis or treatment of port site hernias).
• The final outcome remains unsatisfactory in about 10% of patients due to inadequate weight loss (of less than 10%). This is usually due to difficulty adapting to a healthy, low-fat diet after surgery. In some cases, weight loss remains inadequate due to calories obtained from alcohol.

Postoperative management

• An adequate intake of protein must be ensured after the surgery; the recommended minimum amount is 80-130 g daily.
• The surgery will impair the absorption of certain nutrients. All patients will need to take the following permanently:
  • a multivitamin product (1 tablet daily)
  • 1 mg/day p.o. or 1 mg / 3 months i.m. of vitamin B₁₂
  • calcium (1 000 mg/day) and vitamin D supplementation (20 µg/day)
  • iron (50 mg/day for menstruating women).
• If a patient who has undergone bariatric surgery is vomiting, the possibility of thiamine (vitamin B₁) deficiency must also be considered and, if suspected, the patient must immediately be given intravenous thiamine replacement (200-250 mg daily).
• After surgery, patients should take medication reducing gastric acid secretion for 3 months to prevent ulceration in the seam areas.
• NSAIDs should be avoided as far as possible for the rest of life, since they increase the risk of ulceration in the seam areas.
• Nausea and vomiting are common immediately after surgery but they can usually be controlled by limiting portion size, thorough chewing and regular meals.
• So-called dumping symptoms (sweating, weakness, palpitation, abdominal discomfort, nausea, diarrhoea) may be caused by drinks and foods high in sugar, by eating too quickly and by large portions.
• About 6-12 months after surgery, there may be reactive hypoglycaemia, for which dietary treatment may be helpful (restricted carbohydrate intake and avoiding fast-acting carbohydrates).

Follow-up

• Patients are usually followed up in specialized care for at least one year, and follow-up is subsequently transferred to primary health care.
• Assessment by a plastic surgeon may be necessary after 1-2 years if sagging skin folds forming as the patient loses weight are medically harmful. At that time the patient's BMI should be at most about 30 and the weight loss has to have ended.
• The following should be done annually in primary health care:
  • Assessment of weight development and the need for medication to manage related comorbidities
    • Weight gain commonly occurs after 2 years have elapsed. The patient may be referred to a weight management group again, for example.
    • The risk of excessive alcohol consumption is increased after surgery. Information should be provided on the related adverse effects, as necessary (see articles Recognition of Alcohol and Drug Abuse Brief Interventions for Risky Use of Alcohol). Alcohol consumption may in some cases lead to weight gain.
  • Ensuring regular use of vitamin, mineral and trace element supplements
  • Laboratory tests
    • Blood picture, investigation of anaemia as needed
    • Crea, K, Na
    • Albumin (to ensure sufficient protein intake)
    • Vitamin B₁₂ concentration (if the patient does not receive regular intramuscular injections)
    • Vitamin D concentration (25(OH)D), ionized calcium/albumin-corrected calcium
    • Ferritin
    • Plasma glucose/HbA_1c
    • Lipid profile, if there were abnormalities prior to surgery
    • PTH, Mg, vitamin B1, folate, as necessary
• Bone density should be measured, particularly after gastric bypass surgery, if the patient has lost a great deal of weight, if serum vitamin D concentrations have been low after the surgery or if the patient has other factors predisposing to osteoporosis or if he/she has fractures.
• Problems with the passage of food with associated abdominal pain always warrant a referral to the centre where the surgery was carried out.
• The development of iron deficiency anaemia may be due to an insufficient intake of dietary iron, but may also be suggestive of an anastomotic ulcer or intestinal cancer (gastroscopy/colonoscopy, as necessary).