It turns out, as shown in a recent study, that a procedure known as the “duodenal switch” is better than gastric bypass in achieving weight loss in patients who are very obese, (those with a Body Mass Index of at least 50).
Roux-en-Y gastric bypass is known to be an effective weight-loss operation for patients with a BMI between 35 and 50. For super-obese patients, however, this operation is associated with failure rates approaching 40%, according to the report in the October issue of the Annals of Surgery.
“There has been a perception amongst bariatric surgeons that the duodenal switch might provide better weight loss than gastric bypass in super- obese individuals,” lead author Dr. Vivek N. Prachand, from the University of Chicago, said in a statement.
However, surgeons have been hesitant to adopt the switch operation since it is more technically demanding than gastric bypass, carries a greater risk of nutritional deficiencies, and requires life-long patient follow-up, Dr. Prachand explained. To make a convincing argument for this operation, a study would need to prove that it provides significant advantages over gastric bypass, he added.
New Study Results
The current study, “the first large single institution series directly comparing weight-loss outcomes in super-obese patients” treated with these operations, may provide such proof.
Dr. Prachand and colleagues report that re-operation rates within 60 days were similar among the 198 patients who underwent duodenal switch (9.6%) and the 152 patients treated with gastric bypass (11.2%). There was one death within 90 days in the duodenal switch group, none among the gastric bypass patients.
The excess body weight loss (EBWL) in the duodenal switch group was consistently about 10 percentage points higher than in the gastric bypass group at 12, 24, and 36 months postoperatively. For example, the EBWLs at 36 months were 71.6% and 60.1% in the duodenal switch and gastric bypass groups, respectively.
In keeping with these findings, the likelihood of successful weight loss, defined as an EBWL of >50%, was also significantly higher in the duodenal switch group. At 36 months, the rates of successful weight loss were 84.2% and 59.3% in the duodenal switch and gastric bypass groups, respectively.
“Both procedures appear to be reasonably safe in the hands of an experienced team, but the duodenal switch appears to offer a considerable advantage in terms of the amount and possibly the duration of weight loss,” Dr. Prachand concluded.