Types of weight loss surgery
Operations and procedures to help reduce a person's weight may be an option if other measures, such as diet and medication haven’t worked.
The NHS only considers funding this type of surgery for people with potentially life-threatening obesity, when other measures have not been effective.
The NHS carries out around 5,600 weight loss, or bariatric operations, a year.
Procedures are also available privately.
Like any operation, weight loss surgery carries risks.
How weight loss surgery works
Weight loss surgery works in two ways: by restriction and malabsorption.
- Restriction: This kind of weight loss surgery works by preventing the stomach from stretching to full size. Normally, the stomach can hold 1.5 litres of food. After weight loss surgery, the stomach can hold only around a quarter of a litre. This results in feeling full faster, eating less, and losing weight.
- Malabsorption: Some weight loss operations also divert food around a section of intestine. By skipping an area of intestine fewer calories are absorbed. Lower calorie absorption leads to weight loss.
Most weight loss surgery today is laparoscopic. In laparoscopic surgery, four to six small incisions are made in the abdominal wall. The surgeon inserts tools and a camera through these holes and then operates while watching a video screen.
In open surgery (laparotomy), the surgeon makes a large incision along the middle of the abdomen. This is sometimes necessary, when the surgery cannot be done laparoscopically.
Types of weight loss surgery
Gastric bypass surgery
There are two parts to a gastric bypass:
- The surgeon divides the stomach into a large portion and a much smaller portion. The small stomach portion is then stapled into a small pouch.
- The small stomach pouch is disconnected from the first part of the small intestine (the duodenum). The surgeon reconnects the small stomach pouch to the second part of the small intestine (the jejunum).
After gastric bypass, a smaller amount of food makes a person feel full. He or she eats less and loses weight. Appetite is also reduced. Food also bypasses some of the stomach and a small part of the intestine. This reduces absorption of vitamins and minerals, but doctors now think that there is probably not a significant reduction in calorie or protein absorption.
Laparoscopic adjustable gastric banding
The gastric banding procedure involves the following:
- Using laparoscopic tools, the surgeon places an inflatable silicone band around the upper stomach.
- The band is tightened so the stomach becomes a small pouch with a narrow outlet.
- Afterwards, the patient feels full faster, eats less, and loses weight.
- The band can be tightened or loosened, to minimise side effects and improve weight loss.
Gastric banding is considered a less invasive weight loss operation and the procedure can be reversed if necessary.