Bariatric surgery

Abstract

Background: Bariatric surgery has increased in numbers, but the treatment of morbid obesity in Germany still needs improvement. The new interdisciplinary S3-guideline provides information on the appropriate indications, procedures, techniques, and follow-up care.

Methods: Systematic review of the literature, classification of the evidence, graded recommendations, and interdisciplinary consensus-building.

Results: Bariatric surgery is a component of the multimodal treatment of obesity, which consists of multidisciplinary evaluation and diagnosis, conservative and surgical treatments, and lifelong follow-up care. The current guideline extends the BMI-based spectrum of indications that was previously proposed (BMI greater than 40 kg/m(2), or greater than 35 kg/m(2)with secondary diseases) by eliminating age limits, as well as most of the contraindications. A prerequisite for surgery is that a structured, conservative weight-loss program has failed or is considered to be futile. Type 2 diabetes is now considered an independent indication under clinical study conditions for patients whose BMI is less than 35 kg/m(2) (metabolic surgery). The standard laparoscopic techniques are gastric banding, gastric bypass, sleeve gastrectomy, and biliopancreatic diversion. The choice of procedure is based on knowledge of the results, long-term effects, complications, and individual circumstances. Structured lifelong follow-up should be provided and should, in particular, prevent metabolic deficiencies.

Conclusion: The guideline contains recommendations based on the scientific evidence and on a consensus of experts from multiple disciplines about the indications for bariatric surgery, the choice of procedure, techniques, and follow-up care. It should be broadly implemented to improve patient care in this field.

Figure 1

Gastric banding: An adjustable gastric band is used to divide the stomach into a small proximal compartment (pouch) and a larger distal compartment (residual stomach).

Figure 2

Roux-en-Y gastric bypass: The stomach is taken down a few centimeters distal to the gastric inlet. The jejunum is divided 50 cm beyond the ligament of Treitz, and its aboral end is connected to the small gastric pouch. Some 150 cm distal to this point, the other end of the small bowel is sewn to a loop that has been pulled up to meet it (so-called Roux-en-Y reconstruction). Mechanism of effect: restriction, with an additional malabsorptive component.

Figure 3

Sleeve gastrectomy: More than 80% of the stomach is resected, and the gastric remnant is tubularized, with an initial filling volume of less than 100 ml. Mechanism of effect: restriction and hormonal mechanisms.

Figure 4

Biliopancreatic diversion (BPD) with duodenal switch (DS): First, the stomach is reduced in size as in sleeve gastrectomy. Next, the duodenum is divided distal to the pylorus, and the jejunum is divided 250 cm proximal to the ileocecal valve and anastomosed to the duodenum. The other end is connected to the ileum 100 cm proximal to the ileocecal valve. Mechanism of effect: a combination of restriction with a considerable degree of malabsorption.