A team of researchers from Oslo University Hospital in Norway, led by Dr. Hilde Risstad, compared the 5-year outcomes of two types of bariatric surgery performed on severely obese individuals (BMIs were between 50 and 60; obesity is defined as a BMI over 30). The techniques used were standard gastric bypass surgery (GB), or a technique called biliopancreatic diversion with duodenal switch (BPD-DS).
The participants in the study initially were between 20 and 50 years old; 31 of them were randomly assigned to gastric bypass, and 29 were assigned to the duodenal switch procedure. Both procedures were performed laparoscopically. In the gastric bypass procedure, the stomach is restricted to a small pouch, and then most of the small intestine is bypassed this procedure limits both the amount of food eaten as well as the absorption of nutrients from the food. The BPD-DS involves removing a large part of the stomach, rerouting the food away from the small intestine, and in addition, altering the way that digestive secretions (bile and pancreatic enzymes) affect the digestive process. More information on these procedures can be found both here and here.
Five years post-surgery, the participants who underwent the GB had reduced their BMIs by nearly 14 units (about 91 pounds) , while those with the GPD-DS surgery saw their BMIs fall by over 22 units (about 146 pounds). So on first glance it appears that the GPD-DS would be the method of choice. However, there were some significant drawbacks to this procedure.
Although remission of diabetes and metabolic syndrome, changes in blood pressure and lung function were similar between the two types of surgery, that wasn t true for all parameters examined. The researchers found that participants who had the GPD-DS surgery were significantly more likely to have adverse gastrointestinal effects, as well as lower concentrations of vitamins A and D in their blood. They were also more likely to be hospitalized for surgical problems and have more nutritional deficiencies than people who had the GB surgery.
The investigators concluded We recommend that duodenal switch be used with caution owing to a higher rate of additional surgical procedures and risk of nutritional complications.
ACSH s Dr. Ruth Kava agreed: Although the first line of effectiveness is obviously weight loss, the importance of the negative side effects seen with the BPD-DS procedure must not be minimized. It also will be important to see how these participants fare after a longer follow-up period for example, does one group maintain its weight loss better than others, and can the nutritional deficiencies and other negative side effects of this procedure be satisfactorily rectified.