The vertical sleeve gastrectomy with duodenal switch takes the standard restrictive sleeve gastrectomy and increases its effectiveness by adding a malabsorption element to the operation in the form of a duodenal switch. This procedure is also sometimes known as a biliopancreatic diversion with duodenal switch.
The vertical sleeve gastrectomy divides the stomach vertically and approximately eighty-five percent is removed. The remaining small ‘sleeve shaped’ stomach, which retains the original outlet to the intestines, works very much as a normal stomach and this part of the overall procedure is designed to simply restrict the quantity of food which can be eaten, and thus the number of calories that can be consumed. This part of the operation cannot be reversed.
The second part of the operation involves the creation of a duodenal switch which is designed to restrict the body’s ability to absorb calories from a meal as it passes through the digestive tract.
This is referred to as a form of ‘malabsorption’ surgery and, in the case of the duodenal switch, this can normally be largely reversed.
The intestine is divided and a small section, of normally about 150 cm, is used to create a bypass from the duodenum to a point near the end of the intestinal tract, thereby bypassing most of the digestive tract. The result of this bypass is that food passing through the intestine is only mixed with digestive juices in the final short section of the intestine, giving the digestive juices very little time to digest the food and absorb calories from it into the body.
In many ways the malabsorption element of the duodenal switch is similar to that used in traditional Roux-en-Y gastric bypass surgery, except that the duodenal switch bypasses a far greater proportion of the intestine and allows for considerably less absorption.
The advantages of duodenal switch weight loss surgery include:
- Patients enjoy a better variety of food because, although the stomach is greatly reduced in size, it nonetheless continues to operate much as before, largely because it retains the original opening (pylorus) into the intestine.
- The risk of ‘dumping syndrome’ is eliminated because of the retention of the pylorus.
- The risk of ulcers is lower than in many other forms of surgery.
- The duodenal switch is to some extent reversible for patients who experience problems with malabsorption.
- The procedure is particularly effective in the case of patients with a very high body mass index (BMI).
- In some cases the procedure can be performed laparoscopically.
The disadvantages of duodenal switch weight loss surgery include:
- The high degree of malabsorption can result in anemia, protein deficiency and metabolic bone disease.
- There is an increased possibility that patients will end up with chronic diarrhea.
- The procedure is arguably the most complex of all forms of weight loss surgery and many surgeons believe that the risks are unacceptably high. The list of complications from this form of surgery is extensive and will include:
- Gastric leakage
- Duodenal leakage
- Postoperative bleeding
- Duodenal stomal obstruction
- Small bowel obstruction
- Deep vein thrombophlebitis
- No-fatal pulmonary embolus
- Acute respiratory distress syndrome
Despite its risks, the vertical sleeve gastrectomy with duodenal switch remains a surgical option and can be very effective, especially in patients with a very high body mass index (BMI).
How does the duodenum function?
The duodenum, which is about 25 to 30 cms in length, is the first and shortest section of of the small intestine and connects the stomach to the jejunum tubes. The majority of the body’s chemical breakdown of food takes place within the duodenum.
How do the jejunum tubes function?
The tubes which make up the jejunum are approximately 2.5 m in length (out of a total intestinal length of some 5.5 to 6 m) and form the second of three sections of the intestines. While the duodenum is largely responsible for the chemical breakdown of food, once this process is complete, the jejunum then takes over to absorb nutrients into the bloodstream.