This laparoscopic procedure divides the upper stomach into a small pouch and a large residual region by placing an adjustable band around the fundus. It consists of a soft silicon ring connected to a port system, placed in the epigastric subcutis. Worldwide, the adjustable band is used in 24% of the surgical procedures with a preponderance to European countries [80]. With an estimated rate of 0-0.5%, it has the lowest mortality rate of all bariatric procedures [517]. Long-term results of a 10-year observation period refer to a 13.2% reduction of the initial weight [682]. Short-term studies, however, suggest much higher reduction rates. Complications such as “band slippage,” pouch complications, and decompression of the esophagus might lead to a reoperation rate up to 17% [804].

In this restrictive procedure, the fundus region is divided by a vertical staple line. Additionally, the outlet is wrapped by a band. Long-term weight loss is higher compared to the Adjustable gastric banding [517]. Revision rates of 20-56% mostly affect staple line and band disruption, stomal stenosis, and pouch dilatation [38, 45, 764].

The laparoscopic procedure was originally used as a first-line treatment for super obese patients. It consists of a partial gastrectomy in which the great curvature is stapled off the stomach. As a result of the restrictive technique, the stomach becomes a tube like formation. In addition, ghrelin producing cells of the gastric mucosa are reduced. Compared to adjustable gastric banding, the sleeve gastrectomy results in better hunger control and weight loss. Disadvantage is the irreversible loss of gastric tissue.

The intragastric balloon (IB) is a temporary device for weight loss in moderate obesity [443]. A balloon is placed endoscopically into the stomach and filled with 500 mL of saline solution. Extensive testing is going on; long-term results are still missing. Nausea, abdominal pain, and balloon migration are adverse effects.

Malabsorptive procedures reduce the caloric intake by shortening the transit time and mucosal surface of the intestine. In general, weight loss with malabsorptive procedures tends to be greater than weight loss with restrictive procedures [80]. Though weight loss is excellent, these procedures are associated with multiple complications such as malnutrition, vitamin, and electrolyte deficiencies, as well as liver failure [141, 241]. Therefore, patients undergoing malabsorptive surgery have to be monitored in a lifetime follow-up.

The operation was the first bariatric procedure performed in 1969. It is an end-to-side anastomosis of jejunum to terminal ileum, bypassing most of the small bowel, with the cause of massive malabsorption. Due to its high complication rate and need of revision, the role in up-to-date bariatric surgery is minor.

There are two biliopancreatic diversion (BPD) surgeries: A BPD and a BPD with a duodenal switch (DS) (Fig. 12.3). The BPD consists of a partial gastrectomy and a gastroileostomy. A long segment of the small intestine receives food only; the short common channel receives food and biliopancreatic secretions. The use is limited due to high rates of protein loss, anemia, and stomal ulceration.

In a BPD with duodenal switch (BPD/DS), a smaller portion of the stomach is removed, the remaining stomach remains attached to the proximal duodenum and is connected in terms of an “alimentary limb” to a 150 cm small intestine segment. The remaining duodenum is connected to the lower part of the small intestine variable at length (“enzyme limb”). The common channel in which food and enzymes encounter measures 100 cm.

These procedures are reserved for patients with super morbid obesity (BMI > 50 kg/m²).

The Roux-en-Y gastric bypass (RYGB) is a typical practice of a combined malabsorptive and restrictive procedure and the most common bariatric operation performed in the US.

The stomach is narrowed by creating a small 25 mL pouch at the fundus region. The smaller stomach is connected directly to the 150 cm measuring “alimentary” jejunal portion of the small intestine, bypassing the rest of the stomach and the upper 50 cm “biliopancreatic” portion of the small intestine. Digestion and absorption occur in the common channel (100-150 cm of length) [73, 111].

Early weight loss is rapid, reaches a plateau usually after 2 years. Long-term reduction of 25% body weight is reported in a 10-year observation study [682].

By now, two-third of all bariatric procedures are performed laparoscopically [79]. These techniques provide many advantages compared to open surgery. A lower incidence of hernia, wound infection, and shorter hospital stay are some proven aspects [153, 428, 505, 811].