More weight loss, more problems with duodenal switch

Last Updated: 2015-02-09

By Anne Harding

NEW YORK (Reuters Health) - Patients with a body mass index (BMIs) over 50 will lose more weight with duodenal switch surgery than with gastric bypass, but they'll also face a greater risk of adverse effects, a five-year follow-up study shows.

Based on the findings, the duodenal switch procedure should be used with caution, Dr. Torsten Olbers, of Sahlgrenska University Hospital in Gothenburg, Sweden, told Reuters Health in a telephone interview.

"We shouldn't entirely abandon the idea of doing the duodenal switch, but I think definitely we should look at doing it in two steps," Dr. Olbers added.

There is no consensus on the best type of bariatric procedure for patients with BMIs above 50, Dr. Olbers and his team note in their report, although "gastric bypass may be considered suboptimal owing to insufficient long-term weight loss and substantial weight gain."

At two years of follow-up, their randomized controlled trial in 60 patients found greater weight loss and more improvement in blood lipids with duodenal switch, but worse gastrointestinal adverse effects and more nutritional complications. Health-related quality of life (HRQoL) for the two groups was similar.

The new study reports five-year follow-up data for the study, which was available for 55 patients. Mean BMI reductions were 13.6 for the gastric bypass group and 22.1 for the duodenal switch group.

Remission rates of type 2 diabetes and metabolic syndrome, as well as improvements in blood pressure and lung function, were similar for the two groups. Duodenal switch patients had significantly greater drops in total cholesterol, low-density lipoprotein cholesterol, triglycerides, and fasting glucose, but they also had greater reductions in their serum vitamin A and 25-hydroxyvitamin D serum concentrations.

Patients who had the duodenal switch operation were also more likely to have loose stools (48.1% vs. 11.1%, p=0.01), social limitations due to changes in bowel function (63% vs. 25.9%, p=0.02), and negative effects of bowel symptoms on daily life (66.8% vs. 37%, p=0.03). Still, improvement in HRQoL was similar for the two groups.

Readmission to the hospital within five years of surgery for any reason was necessary for 58.6% of duodenal switch patients and 29% of gastric bypass patients (p=0.02), while 44.8% of duodenal switch patients required additional surgical interventions, versus 9.7% of gastric bypass patients (p=0.002).

Patients who had the duodenal switch procedure were also more likely to have serious nutritional adverse events, such as protein-calorie malnutrition and anemia.

Most patients with BMIs above 50 who undergo gastric bypass wind up with a BMI of around 40 after the surgery, Dr. Olbers noted, so they will still be morbidly obese. However, he added, it's not clear whether it's safe to bring someone from a very high weight to a near-normal weight.

"To be sensible in this, we should take a step back and look at what is achievable and what is really good to achieve for health and function," he added.

"If we have limited resources in offering bariatric surgery . . . from a general healthcare perspective we prefer delivering a safe, not excellent, but reasonable, weight loss with good health and functional improvements with the gastric bypass, compared with stretching it to a duodenal switch, where we might have more side effects," Dr. Olbers said.

The new findings will provide useful information for physicians who are counseling patients considering bariatric surgery, he added.

In an editorial, Dr. Oliver Varban and Dr. Justin Dimick of the University of Michigan in Ann Arbor note that despite its effectiveness, duodenal switch surgery remains the least common bariatric procedure.

Nearly 80% of patients in the current study had at least one adverse event in the five years after duodenal switch surgery, the editorialists note. "The benefits of undergoing duodenal switch hardly seem worth the sacrifice when compared with gastric bypass," they add.

"Given the high complication rates . . . it is difficult to recommend duodenal switch as a first-line weight-loss procedure. At the very least, patients seeking this procedure should receive ample warning regarding the very high risks of adverse nutritional outcomes and the high reoperation rate," Dr. Varban and Dr. Dimick state.

"Patients with poor compliance and poor follow-up should not be offered this procedure because they could be at risk of fatal complications if postoperative problems are not addressed in a timely fashion," they add.

While the duodenal switch procedure could be useful for patients who fail to lose weight with sleeve gastrectomy, they add, the new findings "remind us that this strategy should only be used with great caution and only in a select group of patients with excellent follow-up and compliance."

The study was reported online February 4 in JAMA Surgery.

SOURCE: http://bit.ly/1y0CGzz

JAMA Surgery 2015.