Bariatric Surgery: Weighing the Options

Gastric bypass produced greater weight loss but more risks than adjustable gastric banding

(RxWiki News) For obese people, weight loss surgery can be an effective way to shed pounds. While bypass and banding operations are both popular, one may produce bigger results but also carry greater risk.

Weight loss (bariatric) operations have helped many people who have had difficulty losing pounds through exercise, diet or medication. Two common bariatric surgeries that limit an individual’s food intake are Roux-en-Y gastric bypass and adjustable gastric banding.

A new study has found that patients may lose more weight with a bypass but face more complications than those who have a banding procedure.

David Arterburn, MD, a researcher with the Group Health Research Institute in Seattle, and colleagues conducted the research.

Dr. Arterburn and collaborators compared patients who had either had a bypass or banding operation. They discovered that the average maximum reduction in body mass index (BMI) was 85 percent greater among those who had the bypass.

About 3 percent of the bypass patients in this study, however, experienced major adverse events within a month of the procedure — compared to 1.3 percent in the banding patients. These events included death and blood clots.

With a Roux-en-Y gastric bypass, the stomach is divided in two, creating a stomach pouch out of a small portion of the stomach. This pouch attaches directly to the middle part of the small intestine. Food bypasses a large part of the stomach and duodenum (the upper part of the small intestine). The stomach pouch is too small to hold large amounts of food. Skipping the duodenum can substantially reduce fat absorption.

With gastric banding, a surgeon inserts a band around the upper part of the stomach to create a small pouch to hold food. This limits the amount of food that can be consumed and promotes weight loss.

The researchers analyzed data on 5,950 patients who had gastric bypass and 1,507 who had gastric banding. They followed patients for an average of 2.3 years.

The average maximum BMI loss was 8 points for the banding group and 14.8 for the bypass group. BMI is a measure of body fat based on height and weight.

The study authors evaluated complications in 5,800 bypass patients and 1,192 banding patients. A total of 0.3 percent of those who had the bypass died — compared to 0.2 percent of those who had banding. Almost 20 percent of bypass patients were hospitalized again — compared to 12.4 percent of banding patients.

In related editorial, Justin B. Dimick, MD, and Jonathan F. Finks, MD, of the University of Michigan in Ann Arbor, wrote that bypass may be riskier than band placement. They added that both procedures have low rates for complications, compared with similar abdominal operations.

The authors of the study did note that a greater percentage (13.7 percent) of banding patients required additional procedures — compared to 5.5 percent of the bypass patients.

Dr. Arterburn and team underscored that the banding procedure appeared to have “a more favorable short-term risk profile.” They also indicated that band removal is often one of the additional procedures that banding patients need.

“Removal of bands in the [banding] patients is typically because of failure to achieve or maintain clinically significant weight loss; band malfunction, slippage, or erosion; or patient intolerance of the gastric restriction,” the study authors wrote.

Dr. Arterburn and team concluded that there were important differences in short- and long-term health outcomes for banding and bypass procedures.

“Severely obese patients should be well informed of these differences when they make their decisions about treatment," they wrote.

The study and editorial were published online Oct. 29 in JAMA Surgery.

A grant from the Agency for Healthcare Research and Quality funded the research. One study author received funding from Centocor, Procter & Gamble, Genentech and Medimmune.

Review Date: 
October 29, 2014