Latest Digestion News
By Rita Rubin
WebMD Health News
Reviewed by Laura J. Martin, MD
Jan. 12, 2012 -- An implantable device to treat chronic, severe acid reflux disease has moved one step closer to approval. An FDA advisory committee unanimously voted that the LINX device was safe and effective for treating chronic gastroesophageal reflux disease, or GERD, that does not respond to medication.
The panel also unanimously voted that the benefits of LINX for those patients outweigh the risks. The FDA usually, but not always, follows its advisory committees' guidance.
The LINX device is a titanium ring of magnetic beads. It's placed around the lower end of the esophagus to strengthen the sphincter, or ring of muscle, that's supposed to prevent acid and other stomach contents from rising. At the same time, it is said to be pliant enough to allow food and liquids to enter the stomach.
Manufactured by Torax Medical of Shoreview, Minn., LINX has been on the market in the United Kingdom, Germany, and Italy for about two years, according to Todd Berg, the company's president and CEO.
About 19 million U.S. adults suffer from GERD, FDA medical officer Priya Venkataraman-Rao, MD, told the panel. Doctors recommend treating it first with nonsurgical methods, such as raising the head of the bed, losing weight, eating smaller meals, or taking antacids or other medications called H2 blockers or proton-pump inhibitors.
If none of those work, the main alternative is a surgical procedure in which the top part of the stomach is cut and wrapped around the esophagus.
Clinical Trial Patients Had Suffered From GERD for Years
Torax implanted 100 patients with LINX in its pivotal clinical trial. On average, they'd suffered from GERD for 13 years and experienced about 80 episodes of heartburn a week. People with a BMI greater than 35, a large hiatal hernia (when the stomach bulges into the chest through an opening in the diaphragm), a history of trouble swallowing (more than once a week for the previous three months), a severely inflamed esophagus, or Barrett's esophagus -- in which the lining of the esophagus, damaged by acid, becomes more like the lining of the intestine -- were excluded from the study.
The acid level in the patients' esophagus was assessed before and 12 months after LINX was implanted via minimally invasive "keyhole" surgery. Just over half of the patients saw their acid level fall by at least one-half.
Improvement on a subjective quality-of-life assessment -- which asked such questions as when and how often heartburn occurred and whether it kept them up at night -- was even greater, both at 12 months and 24 months after surgery, Venkataraman-Rao said.
But because the study did not have a comparison group that did not get the device, there's "no way of knowing whether subjects would have improved on their own," Venkataraman-Rao said.
Three-quarters of the implanted patients experienced side effects, the most common being difficulty swallowing, which in some cases took six months or more to resolve, she said. The second most common side effect, reported by a quarter of the patients, was pain. The implant had to be removed from five of the patients.
Because LINX is magnetic, patients who might need MRI scans would not be eligible to have it implanted.
Torax says it plans to conduct a follow-up study of 200 patients to confirm the device's long-term safety and effectiveness.
Advisory committee member Steven Schwaitzberg, MD, an associate professor of surgery at Harvard, urged that the company follow patients for at least 10 years. "I think it's going to be an obligation that we have to the public," Schwaitzberg said.
"I'm really worried about safety," he said, noting that LINX could stay in some patients for as long as half a century.
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