On the heels of a Feb. 16 decision by the Food and Drug Administration to make millions more people eligible for laparoscopic gastric banding (lap band) weight loss surgery, a new study suggests the more invasive gastric bypass may be better.
Researchers from the University of California, San Francisco, compared the effects of lap band and gastric bypass among 200 morbidly obese patients treated at the UCSF Bariatric Surgery Program. Gastric bypass led to greater weight loss, increased resolution of diabetes and improved quality of life one year after surgery, they reported today in Archives of Surgery.
Complication rates were similar between the two procedures, but re-operation rates were lower for gastric bypass, leading the researchers to conclude that the risk-benefit profile for gastric bypass was superior.
But experts urge caution in interpreting the study's results, and stress that the varying benefits and risks of either procedure make the decision a personal one.
"If a patient's primary interest is to lose their diabetes, then gastric bypass is better. If the patient prefers slower weight loss, then banding is better," said Dr. Theodore Khalili, founder and director of the Khalili Center for Bariatric Care in Beverly Hills and former director of the Weight Loss Surgery Program Cedars-Sinai Medical Center. "Unless there is an absolute contraindication to one procedure, then we let the patient decide."
Roughly one-third of Americans are obese with a body-mass index over 30, and five percent are morbidly obese with a BMI over 40, according to the Centers for Disease Control and Prevention. The extra weight boosts the risk of type 2 diabetes, heart disease, stroke, cancer, and even death. While weight loss surgery can help obese people shed the extra pounds and some of the related health risks, the surgical risks and the cost (upwards of $20,000) make the decision not one to be taken lightly.
With roughly 180,000 operations per year in the United States, gastric bypass is the most common weight loss surgery. The procedure physically shrinks the stomach and forces food to bypass part of the small intestine, causing people to feel fuller after eating less, and fewer calories to be absorbed.
But since its approval by the FDA in 2001, lap band surgery is picking up steam. Its use rose from 7 percent to 23 percent between 2004 and 2007, according to a 2009 study published in Surgery for Obesity and Related Diseases. Gastric bypass use rose from 53 percent to 66 percent during the same period.
Like gastric bypass, lap band makes the stomach smaller so people feel fuller. But it does not reroute food and cause fewer ingested calories to be absorbed, so the effects are slower.
"The lap band works over two to three years, while the maximum benefits of the gastric bypass surgery are at a year to year-and-a-half," Khalili said. "This study is not comparing apples to apples because the endpoint may be a little premature for the band," he said.
"Their results are not surprising given the fact that the follow-up was for only one year. If their five year follow-up demonstrates true superiority of gastric bypass then this paper might help change clinical practice," said Dr. Scott Belsley, director of robotic surgery at St. Luke's – Roosevelt Hospital in New York City.
Lap band was initially touted as a "safer and less invasive" alternative, according to the study. And although the risk of both types of bariatric surgery is decreasing, gastric bypass is still considered the more complicated and riskier of the two with a 10 to 18 percent morbidity rate and a 0.1 to 0.3 percent mortality rate.
Although the initial effects of gastric bypass surgery on weight and diabetes may be superior to those of lap band, the long term effects are less clear.
"Having practiced bariatric surgery for 17 years, I know that gastric bypass is a great weight loss operation. My concern is that it is not a great operation for maintaining the weight loss," said Dr. Mitchell Roslin, a bariatric surgeon at Lenox Hill Hospital in New York City.
Roslin said people who had gastric bypass surgery regain an average of 15 percent of their weight within three years -- an effect that may be due in part to a return of inter-meal hunger, he said.
"As a result, we are seeing many patients five to ten years from surgery who have regained 50 percent or more of the weight they have lost. With this, there is a return of some of the medical problems that seemed to have resolved," Roslin said.
Last week, the FDA expanded the lap band eligibility criteria to include people with a BMI over 30 who have at least one related health condition, such as diabetes. It's estimated that another 25 million Americans now qualify for the procedure.
Dr. Bruce Wolfe, professor of surgery at Oregon Health and Science University in Portland and president of the American Society for Metabolic and Bariatric Surgery said he thinks the FDA should have lowered the obesity bar for lap band even further to include people with a BMI between 30 and 35 who have a related health condition and people with a BMI between 35 and 40 with no related health problems. His rationale: Obesity is a disease that shortens life and is associated with a long list of related health conditions, and is therefore appropriate to treat effectively.
Previously, people with a BMI under 35 were ineligible altogether.
But the expanded criteria is unlikely to cause a surge in lap band procedures, Wolfe said. One reason is that insurers aren't yet covering the procedure in newly-eligible patients, meaning they would have to pay out-of-pocket.
"The insurance companies may require a higher level of evidence than is required by the FDA for approval of a device," Wolfe said.
But even among eligible, potentially insured patients, the surgery rates are low, Wolfe said.
"We estimate that less than 2 percent of the eligible population actually undergoes surgery in a year," Wolfe said. "Most of the people who are eligible are not receiving surgery now."
ABC News' Jane Allen contributed to this report.