Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

For super-obese patients, duodenal switch beats gastric bypass

26.09.2006
In the first large, single-institution series directly comparing weight-loss outcomes in super-obese patients, researchers from the University of Chicago found that a newer operation, the duodenal switch, produced substantially better weight-loss outcomes than the standard operation, the Roux-en-Y gastric bypass.

In the October issue of the Annals of Surgery, the researchers report that the duodenal switch (DS) produced greater weight loss than the Roux-en-Y gastric bypass (RYGB) by all measures in patients with a body mass index (BMI) of at least 50. These patients typically carry at least 150 pounds more than their ideal weight.

In this study, patients undergoing duodenal switch were significantly more likely to achieve and maintain successful weight loss--defined as losing more than half of their excess weight--at one year (DS 83.9% vs. RYGB 70.4%) and three years (DS 84.2% vs. RYGB 59.3%) after surgery.

"While there is no single ideal bariatric procedure that can be applied to all severely obese patients, we have generally recommended the duodenal switch for those with a BMI greater than 50," said study author Vivek Prachand, M.D., assistant professor of surgery at the University of Chicago. "This study confirms that approach. 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."

The super obese make up only a fraction of the U.S. obesity pandemic, but their ranks are increasing faster than any other group. When the term was coined in 1987, fewer than one in 2,000 adults in the United States met the criteria of a BMI greater than 50. (A normal BMI is 18.5 to 24.9. From 25 to 29.9 is considered overweight. Thirty or above is considered obese; 40 and above is morbidly obese.) The prevalence of the super-obese has quintupled since then, to one in 400 U.S. adults in 2000, which adds up to more then 50,000 people in the U.S.

At the same time, bariatric or weight-loss surgery has increased from about 16,000 cases in 1992, to 63,000 in 2002, to 171,000 in 2005. The most common surgical procedure for these patients--more than 80 percent of all bariatric operations in 2002--is the gastric bypass, which involves stapling off a large portion of the stomach to make overeating difficult, and rerouting the intestines to reduce the absorption of calories. The duodenal switch--fewer than eight percent of all bariatric procedures performed nationwide--leaves a slightly larger stomach pouch but makes even more drastic alterations to the intestines to limit absorption, particularly of fats and starches.

This study involved 350 consecutive super-obese patients who underwent weight-loss surgery at the University of Chicago Hospitals between Aug. 5, 2002, and Nov. 10, 2005. One hundred ninety-eight patients underwent duodenal switch and 152 had a gastric bypass. More than 80 percent of both groups were female. The average age was 40, but that ranged from 18 to 68. About 92 percent had the surgery performed laparoscopically, through small abdominal incisions.

The duodenal-switch patients were slightly heavier. Their average weight before surgery was 368 pounds, compared to 346 for gastric-bypass patients. Average BMIs were also higher: 58.8 for the duodenal-switch patients (up to 96.3), compared to an average BMI of 56.4 for gastric-bypass patients (up to 84.2).

On average, patients who had a duodenal switch stayed in the hospital one day longer, four days instead of three. About 24 percent of DS patients stayed more than four days and about 20 percent of RYGB patients stayed more than three days. There was one death among the 198 duodenal-switch patients within 30 days of the operation and no deaths before 30 days among 152 gastric-bypass patients.

The duodenal switch produced greater weight loss. DS patients lost more total weight and a larger percentage of excess body weight and consequently had a bigger decrease in BMI. When they were weighed one year after surgery, DS patients had lost an average of 149 pounds compared to 121 pounds for RYGB patients. After three years, DS patients had lost 173 pounds, but average weight loss for RYGB patients had decreased to 118 pounds.

"Every one of these patients had significant weight loss," Prachand said, "but the duodenal-switch patients had greater weight loss and seemed to keep the weight off longer."

"There has been a perception amongst bariatric surgeons that the duodenal switch might provide better weight loss than gastric bypass in super-obese individuals," said Prachand. Several studies have demonstrated higher rates of weight-loss failure and weight regain following gastric bypass in these patients.

But surgeons have been hesitant to adopt the duodenal switch for several reasons, he said: "greater technical complexity of the operation, particularly when performed laparoscopically; greater potential for nutritional deficiencies; and need for life-long medical follow-up."

"Given these concerns," he said, "it would be difficult to recommend duodenal switch without demonstrating a significant advantage over the gastric bypass, which is generally a very effective operation in severely obese patients. Our study demonstrates an advantage with regards to weight loss."

"We still need longer-term data on these patients," he added. "We are currently comparing nutritional outcomes and improvement in obesity-related medical problems, including type 2 diabetes, high blood pressure, elevated cholesterol levels, acid reflux, and obstructive sleep apnea in these patients. We don't know yet how much weight loss we need to get those health benefits, but losing more of the excess weight certainly seems to be better."

John Easton | EurekAlert!
Further information:
http://www.uchospitals.edu

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>