Obesity Surgery for Metabolic Diseases -Updated German Guideline

Germany: A multidisciplinary panel of experts has developed an updated guideline on obesity surgery for the treatment of metabolic diseases. The guideline, published in the journal Deutsches Arzteblatt International, was created on the basis of publications retrieved by a systematic literature search.

Treatment Objectives

The newly formulated objective of obesity surgery and metabolic procedures is to bring about a sustained loss of weight and, through the beneficial effects of weight loss, to achieve the following:

• Longer survival


• Better quality of life


• Remission, improvement, and/or prevention of the comorbidities and sequelae of obesity


• Continued participation in work and in social and cultural activities.

The goals of treatment should always be individually defined and adapted to any changes that take place.

Definition of Centers

Centers were defined in accordance with the certification rules of the DGAV and the Swiss guideline on the surgical treatment of obesity.

There was a strong consensus among the experts that the following types of patients should undergo surgery only in a center with special expertise, and that the specified techniques should only be performed in such centers (however, this is not evidence-based):

• Patients under age 18, or aged 65 and above


• Distal bypass operations, conversion operations, and redo operations


• Patients with BMI ≥ 60 kg/m²


• Patients at elevated risk with severe comorbidities (American Society of Anesthesiologists [ASA] score >3)


• Procedures that are primarily for the treatment of metabolic disease (in patients with BMI <40 kg/m², in collaboration with a physician who is an expert in the treatment of diabetes/a diabetologist).

Surgical indications

The treating team that establishes the indication for surgery should consist of the following members:

• A physician who is an expert in the treatment of diabetes/a diabetologist, if surgery for metabolic indications (type 2 diabetes) is to be performed.


• A nutritionist or physician with special expertise in nutrition who has experience in obesity surgery


• A mental health professional with experience in obesity surgery


• An internist/general practitioner/physician with special expertise in nutrition who has competence in the surgical treatment of obesity and metabolic disorders


• A surgeon with competence in the surgical treatment of obesity and metabolic disorders

Obesity surgery is indicated in the following situations:

• In patients with BMI ≥ 40 kg/m² without any comorbidities or contraindications, when conservative treatment options have been exhausted and after the patient has been thoroughly informed.


• In patients with BMI ≥ 35 kg/m², after the exhaustion of conservative treatment options, in the presence of one or more obesity-associated comorbidities, such as: type 2 diabetes, coronary heart disease, congestive heart failure, hyperlipidemia, arterial hypertension, nephropathy, obstructive sleep apnea syndrome (OSAS), obesity-hypoventilation syndrome, Pickwick syndrome, non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH), pseudotumor cerebri, gastro-esophageal reflux disease (GERD), asthma, chronic venous insufficiency, urinary incontinence, immobilizing joint disease, impaired fertility, or polycystic ovarian syndrome.


• A primary indication for obesity surgery (i.e., without any requirement for prior exhaustion of conservative treatment modalities) exists if one of the following conditions is present:
  
  
  
  • BMI ≥ 50 kg/m²,
  
  
  • Whenever, in a specific case, the multidisciplinary team considers a trial of conservative treatment to have little or no chance of success, and
  
  
  • Whenever especially severe comorbidities and sequelae of obesity are present that make any further delay before surgery inadvisable.
  
  
  
  

Surgery is indicated to treat a metabolic disturbance in the following situations:

• Metabolic surgery should be recommended as a primarily indicated treatment option, as defined above, to patients with type 2 diabetes who also have a BMI ≥ 40 kg/m², as such patients stand to benefit both from the antidiabetic effect and from the weight-reducing effect of the intervention.


• Metabolic surgery should be recommended as a potential treatment option to patients with type 2 diabetes whose BMI lies in the range of ≥ 35 kg/m² to <40 kg/m² if their individual target values, as determined from the National Disease Management Guideline on the Treatment of Type 2 Diabetes, have not been achieved.


• Metabolic surgery can be considered for patients with type 2 diabetes whose BMI lies in the range of ≥ 30 kg/m² to <35 kg/m² if their individual target values, as determined from the National Disease Management Guideline on the Treatment of Type 2 Diabetes, have not been achieved.

Contraindications

There was also a strong consensus among the experts regarding contraindications. Obesity surgery and/or surgery for metabolic indications should not be performed in the following situations:

• If the patient is in an unstable psychopathological state, e.g., untreated bulimia nervosa or ongoing substance dependence


• In the presence of underlying diseases associated with a catabolic state, malignant neoplasms, untreated endocrine disturbances, or other chronic diseases that could be made worse under the catabolic conditions brought about by the operation


• If the patient is pregnant or intends to become pregnant in the near future.

These contraindications are relative, except for pregnancy, and they are not supported by evidence.

Surgical Procedures and Results

No procedure can be recommended as a universal standard; the choice of treatment is an individual one, taking due consideration of the initial weight, accompanying diseases if any, the patient’s wishes, etc. Currently established standard techniques include gastric banding (laparoscpic adjustable gastric banding, LAGB), sleeve gastrectomy (SG), proximal Roux-en-Y gastric bypass (RYGB), omega-loop gastric bypass (MGB), and biliopancreatic diversion with or without duodenal switch.

Postoperative Care

Meticulous postoperative care is indispensable and is supported by a strong expert consensus. The evidence regarding the proper extent of postoperative care is not of high quality, but the outcome is clearly better in patients who receive intensive postoperative care and participate in self-help groups.

The key elements of postoperative care are the following:

• Checking whether the goal of treatment has been reached


• Monitoring comorbidities and changing medications as indicated


• Encouraging the patient to exercise and follow a proper diet


• Early recognition of complications, etc.

Laboratory values should be checked at 6 and 12 months, and thereafter at intervals depending on the particular surgical procedure and on the patient’s comorbidities. At least the following should be checked:

• Complete blood count, electrolytes, hepatic and renal function tests, blood glucose and HbA_1c (only in diabetics), vitamins B₁and B₁₂, albumin, calcium, folic acid, ferritin


• After any type of bypass procedure: 25(OH)D₃, parathormone, vitamin A


• After distal bypasses: zinc, copper, selenium, magnesium.

For further reference follow the link: 10.3238/arztebl.2018.0705