Several forms of this procedure have been performed over the last three decades. It is based on an operation which has been used to treat stomach ulcers and cancers for more than a century, and the name is derived from the name of the French surgeon who first described the use of a small segment of small bowel to divert bile and acid away from the stomach and oesophagus. The current operation involves a restrictive element (considerably r educing the size of part of the stomach) and a hormonal component (early passage of food into the intestine). These two factors give the strongest possible appetite suppression. This makes weight loss relatively straightforward in the great majority of people.
This operation has a very good combination of effectiveness (how much weight is lost) and durability (how long weight loss lasts). It avoids some of the dietary limitations of restrictive operations and the nutritional deficiencies of intestinal bypass operations. It accounts for 60 per cent of obesity surgery worldwide .
Most of the published evidence leading to the worldwide acceptance of obesity surgery by government health agencies in Australia, America and the United Kingdom is based on gastric by pass surgery, which is the gold standard against which other weight loss methods are currently judged.
Figure. Gastric by pass. Has a small – volume gastric pouch, a narrow outlet from the divided stomach, and bypass of part of the small bowel
In some people, a ring can be placed around the stomach pouch during the operation , to limit the risk of weight regain.
In larger patients, or those who are habitual large – meal eaters, a ring can be placed around the gastric pouch to prevent it softening due to forceful eating. Pouch softening may otherwise lead to increased capacity and later weight regain. Due to the ready availability of a high – quality band, I now perform the banded bypass as my routine procedure, unless technical or patient factors make this unwise
This operation has been around for about 10 to 15 years and is becoming more popular, although not all outcomes are known. It has similar results to standard bypass but it is easier to perform (hence its increasing popularity). It has a lower risk of obstruction of the small bowel than a standard bypass, but higher risks of reflux. This may be the ideal operation for very overweight men for whom a standard gastric bypass may be difficult, or for patients with adhesions in the small bowel.
Advantages: Effective, long – lasting weight loss in more than 85 per cent of cases. Different versions of the banded gastric bypass, such as the mini gastric bypass, allow for some flexibility during the operation.
Disadvantages: Vitamin supplements should be taken daily. Some menstruating women will need iron tablets. Post – menopausal women probably should take calcium tablets. The operation has similar or slightly lower risk of operative complications (but a greater risk of post – operative complications) to the sleeve gastrectomy. The risks are similar in magnitude to elective hip or knee surgery (1 in 200 to 1 in 1000 risk to life). There is a 5 per cent chance of bowel blockage in the years after surgery. People who have previously had complex abdominal surgery can have adhesions that make laparoscopic bypass difficult. These people may therefore require open surgery or consideration of other options