Chronic sufferers of gastroesophageal reflux disease (GERD) may qualify for a study at Houston Methodist Hospital that compares an FDA-approved device to medical management.

GERD is a chronic, progressive disease that affects 20 percent of the U.S. population. It occurs when a valve at the lower end of the esophagus weakens and opens too easily. The opening of the valve allows the contents of the stomach to wash back (reflux) into the esophagus causing heartburn, regurgitation, loss of sleep and, in some cases, dietary restrictions. 

The CALIBER study compares the LINX® Reflux Management System to a double-dose of the proton pump inhibitor (PPI) omeprazole, commonly known as Prilosec, in patients who continue to have GERD symptoms while taking single-dose PPIs. The Phase IV, randomized study at Houston Methodist Hospital, led by Drs. Patrick Reardon and Karen Woods, compares the LINX implant to medical therapy with 20 mg of omeprazole, twice a day. 

“The long-term use of PPIs has been linked to a possible increased risk of bone fractures and increased risk of certain gut infections. Other less well defined risks have also been proposed,” said Reardon, head of the hospital’s minimally invasive surgery program. “Concerns about continued reflux symptoms while on the medication and the lifelong use of PPIs may cause some patients to seek a surgical alternative. We owe our patients the opportunity to see if this device can alleviate their ongoing GERD symptoms without the use of these medications.”

While PPIs remain the most common form of treatment for GERD, surgery can be an effective alternative for patients who still have symptoms, even when they are taking PPIs.

The LINX implant is made of intertwined titanium beads with magnetic cores and is in the shape of a ring. The device is inserted through a small incision in the abdomen, placed near the lower esophageal sphincter, and designed to prevent the valve at the end of the esophagus from opening. The magnetic attraction between the beads allows food to pass through to the stomach; then, the magnets snap back into place, keeping the valve from opening and preventing food from reentering the esophagus from the stomach. By preventing reflux at its root cause, the implant avoids any complications associated with long-term use of drugs that treat only the symptoms of GERD. The use of the LINX device has fewer side effects than the traditional minimally invasive surgery called fundoplication.

PPIs work by blocking the site of acid production in the stomach. Besides omeprazole, other PPIs include esomeprazole, lansoprazole, pantoprazole and rabeprazole, and have various brand names, such as Prilosec, Nexium and Prevacid. In addition to PPIs, H2 blockers comprise another type of antacid drug (commonly known as Zantac or Tagamet), but these medications have been less effective in treating GERD symptoms.

Woods, a gastroenterologist at Houston Methodist Hospital who has treated GERD patients for decades, chaired the FDA panel that approved the LINX device in 2013 to combat GERD. 

Study patients randomized to the medical therapy arm of the trial will be reviewed after six months to see if they qualify for the LINX device. If not, medical management will be reduced to one dose of omeprazole a day. Patients who undergo the laparoscopic procedure for the LINX device can go home the same day.

Approximately 20 sites in the United States will offer the CALIBER study to about 150 patients. Houston Methodist Underwood Center for Digestive Disorders expects to enroll 15 patients. The project is funded by Torax Medical. For more information on the CALIBER study, call 713.441.3250.

To speak with Pat Reardon, M.D., contact Gale Smith, Houston Methodist, at 281.627.0439 or For more information about Houston Methodist, visit Follow us on Twitter and Facebook.