[Quality of indications in bariatric surgery].

Bariatric and metabolic surgery is increasingly being utilized in Germany and also worldwide. Due to the increased perioperative risk compared to non-obese patients, a detailed and accurate preoperative assessment of the patient is pivotal to improve postoperative and long-term outcomes. The indications for bariatric surgery have shifted in recent years from a certain body mass index (BMI) to comorbidity-based indications. In 2018 the German S3 guidelines for metabolic surgery defined the indications for bariatric surgery as well as the preoperative assessment. The indications for bariatric metabolic operations should be assessed by an interdisciplinary team consisting of surgeons, internists, diabetologists, psychologists and dietitians. It is paramount that surgeon and patient define realistic goals of these operations. Also, the different types of bariatric operation and their long-term consequences should be discussed. Additionally, a thorough endocrinological assessment by an internist or diabetologist with respect to relevant comorbidities of obesity as well as the adjustment of existing therapies are important. An assessment by a mental health professional is also mandatory; however, psychological comorbidities are not a contraindication as long as the patient is being treated and the disease is controlled. A preoperative short-term high-protein and low-carbohydrate fluid nutrition helps to reduce the risk of postoperative complications, especially for patients with a high BMI. A preoperative weight loss in the sense of a mandatory loss of a defined proportion of the body weight is not useful.