This section contains brief descriptions of the bariatric surgical procedures that are most commonly carried out.

Adjustable Gastric Band

The adjustable gastric band is a laparoscopically positioned device which restricts the amount of food that can enter the stomach. It is placed just below the gastro-oesophageal junction, allowing the formation of a small pouch of about 30 ml volume into which the oesophagus opens.

The inner aspect of the band contains an inflatable silicone balloon which is connected to a subcutaneous port. This is used to fill or remove fluid to tighten or relax the restriction caused by the band over a period of weeks to months following the surgical procedure

Band insertion carries a lower risk of morbidity and mortality than bypass procedures, but also results in a lower level of weight loss. It is unsuitable in individuals who are unable to make significant dietary changes. Close follow-up and multiple band adjustment may be needed before optimum performance is achieved.

Roux-en-Y Gastric Bypass

This is a more involved procedure than band insertion. The stomach is divided to leave a small proximal pouch. The small intestine is divided about 75 cm to 1 metre from the antrum and the distal part of the intestine is anastomosed to the small stomach pouch. The distal end of the divided proximal small bowel is then anastomosed lower down the small intestine.

Roux-en-Y Video

The small stomach pouch may have a restrictive effect, but the bypass component results in malabsorption of food. Furthermore, changes in gut hormone release result in a decrease in appetite, hunger and eating behaviour.

This procedure results in better weight loss than band surgery, but malabsorption, e.g., vitamin B12 and calcium is common. There is also higher potential for surgical complications and the “dumping syndrome” is common – light-headedness, palpitations and diarrhoea within 30 minutes of sugary intake.

Intragastric Balloon

An intragastric balloon is an endoscopically placed device. It consists of an inert ballloon, approximately 600 ml in volume, which severely restricts the amount of food that can be ingested. Such a device can only be placed for a maximum of 6 months, after which it must be removed. Severe vomiting often occurs in the initial stages after such a balloon is placed.

These devices are sometimes used in individuals whose medical condition and extreme BMI make laparoscopic surgery very risky. Once they have lost some weight with a balloon, a bypass procedure may become possible.

Vertical Banded Gastroplasty

This provides a fixed restriction by means of a band around part of the stomach, the rest of the stomach being closed off with staples. This procedure is no longer widely performed.

Other Malabsorptive Procedures

The Roux-en-Y bypass procedure is the commonest malabsorptive bariatric procedure performed worldwide, but there are various types of procedure that are performed to achieve greater malabsorption, such as biliary-pancreatic diversion (BPD), duodenal switch (DS) procedure and others. In a BPD procedure, about two-thirds of the stomach is resected to leave a small proximal portion which is anastomosed directly to the terminal 100 cm or so of the ileum. The duodenum and jejunum become no more than a conduit for bile and pancreatic fluids.

In the duodenal switch version, the duodenum is divided proximal to the ampulla and the distal intestine is anastomosed to the proximal part, thus receiving the outflow from the stomach antrum. As in the BPD procedure, the duodenum and jejunum carry no food, and are anastomosed end-to-side to the ileum. Additionally, the stomach is divided longitudinally to reduce its capacity, a procedure that may be performed in isolation as a sleeve gastrectomy, or as the first part of a two-part DS procedure. The preserved gastric antrum in DS surgery reduces the risk of dumping syndrome.