For patients who are obese and have Type 2 diabetes, gastric bypass can be a remarkable cure: After such surgery, more than three-quarters of such patients can significantly reduce or discontinue their diabetes drugs within a year, studies show. With that in mind, diabetes and obesity specialists meeting this week in New York City returned again and again to a central question: how to deliver benefits of bariatric surgery without the risks of major surgery?
One proposal: a 2-foot gastrointestinal "sleeve" that can be implanted through the mouth and that lines a small part of the small intestine, just below the stomach. Such a device, recently approved for use in Europe and parts of South America, was reported last week to have improved the metabolic function of diabetic patients on par with gastric bypass. A second study found that, in a year, it led to an average loss of 46% of excess weight -- a track record that would make it less effective than gastric bypass for weight loss but roughly as effective as gastric banding, according to Dr. Lee Kaplan of Harvard University Medical School.
FOR THE RECORD
An earlier version of this article incorrectly said the gastrointestinal "sleeve" lines a small part of the large, or upper, intestine. It lines a section of the small intestine.
Those results were presented at the Second World Congress on Interventional Therapies for Type 2 Diabetes, which met in New York earlier this week.
Kaplan, who is a consultant to GI Dynamics, the company that has developed the gastrointestinal sleeve, is director of obesity research at Massachusetts General Hospital and chief of the hospital's weight center. Kaplan also was co-author of the larger of the two studies presented this week, which tracked 27 subjects who got the gastrointestinal liner for a year.
But at roughly $5,000, the EndoBarrier, considered an advanced investigational device in the United States, is not a permanent solution to diabetes, even for patients who respond well to it. Nor is it without risks of its own. It is designed to stay in the gut for no more than a year, after which physicians believe most patients will revert to their diabetic condition. And while it can be put in place in 25 minutes under sedation that keeps a patient conscious, it was found in one study presented this week to have slipped, become obstructed, or caused problems leading to its removal in more than one-in-three cases. Intestinal bleeding can result if it becomes dislodged.
The gastric sleeve "seems to capture some of the effect" by which gastric bypass surgery improves metabolic function in diabetics, said Kaplan. By lining a 2-foot portion of the intestine, it alters the complex mix of hormones secreted in the gut that affects appetite, digestion and metabolism.
At the same time, Kaplan said that the device's one-year design life may limit its effectiveness as a long-term solution to obesity and diabetes. By giving a diabetic's pancreas a year to rest, it may improve a patient's long-term outlook, he speculated. And some patients, he added, may benefit from having the device implanted over and over, with a break in between. But such possibilities have yet to be demonstrated in clinical trials, he cautioned.
In the meantime, Kaplan suggested a one-year respite from diabetes could be valuable for obese diabetic patients who need to improve their metabolic function before they can undergo needed surgery or radiation therapy. For obese women with Type 2 diabetes who are planning a pregnancy, he said, a temporary improvement in metabolic function could reduce pregnancy complications and lower the risk that her child will grow up obese and diabetic.
University of Wisconsin bariatric surgeon Guilherme Campos said the endoscopically inserted sleeve had been a "very good" option in Europe for patients who cannot safely undergo gastric bypass until they lose some weight. But, he added, "the expectations should be clear that this is a temporary measure to bridge patients to more definitive treatment."
Between 300 and 500 of the gastrointestinal liners have been implanted into patients around the world -- all in investigational settings. In preparation for a likely submission for the FDA's approval, GI Dynamics is set to begin a multi-center clinical trial of the sleeve in the United States, with as many as 500 new subjects.