SAN FRANCISCO, May 24 (UPI) -- That uncomfortable catheter winding through the nose for 24 hours to monitor levels of stomach acid washing into the esophagus for managing heartburn, acid reflux and related problems may soon be retired, a stomach specialist predicted Thursday.
Dr. Joel Richter, of the Cleveland Clinic Foundation, has helped to develop a catheter-free alternative about the size of a vitamin capsule. He hopes to make pH monitoring more tolerable for the hundreds of thousands of people in the United States who must endure catheters each year. He also expects his system's relative ease to induce the many who have been avoiding pH monitoring -- at some risk to their health -- to try it.
"I'm guessing over time in the next year or two this is probably going to replace nasal catheters for most pH studies or double or triple the number of patients," said Richter, chairman of the foundation's department of gastroenterology. He helped develop the Bravo pH Monitoring System, which was launched this week by leading medical technology manufacturer Medtronic Inc. at the Digestive Disease Week conference.
The name of the disease that generates the acid, heartburn, and other symptoms with the potential to damage the lining of the esophagus and even the enamel on teeth, is GERD, for gastroesophageal reflux disease. It affects about 7 million Americans each year.
GERD happens when the sphincter muscle that empties into the stomach from the esophagus is relaxed too often, and becomes unable to stop the regurgitation of stomach acid.
Richter provided an update on the system at the annual conference. He told attendees his system was potentially more accurate and far more comfortable than nasal catheters because daily activities are not impaired.
The capsule, which includes a tiny radio transmitter, is placed with the help of an endoscope on the wall of the lower esophagus, nearly 2-1/2 inches up from where the esophagus empties into the stomach. The capsule monitors the pH level for up to two days, without inhibiting the movement of the patient, all the while transmitting data about acid levels to a pager-like device the patient wears. The data are later downloaded to a computer for analysis.
Over time, the capsule sloughs off the esophagus passes spontaneously through the digestive tract, usually without the patient noticing and within 14 days, Richter said.
In one study of 11 patients with GERD and 11 healthy controls, researchers found the system properly diagnosed nine of 11 patients known GERD patients, or 82 percent, after two days of continuous monitoring, an improvement from 6 of 11 patients, or 55 percent, based on data recorded only after the first 24 hours of attaching the capsule.
In a second paper released at the conference, the Bravo system successfully recorded esophageal acid exposure in 95 percent of 27 patients during a 24-hour period.
Richter said the cost would be similar to that of nasal catheter systems.
Dr. Roy Wong, chief of gastroenterology at Walter Reed Army Medical Center in Washington, D.C., and director of the division of digestive diseases of the Uniformed Services University of the Health Sciences in Bethesda, Md., told United Press International that he doubted he would adopt Richter's capsule system at his facilities.
"It's a possibility -- I didn't think so," he said, appearing surprised that he would even consider phasing out catheters, which he has used for 20 years. The size of catheters has been decreasing, and they are becoming somewhat less burdensome, he said.
Wong did mention some caveats based on his reading of the abstracts released at the meeting. He noted that there were three failures out of 61 subjects. Two failures occurred because the capsule detached prematurely, and one failed due to poor data capture. Also, in two other cases, the capsules had to be removed endoscopically because of discomfort. In one other case, the capsule failed to spontaneously detach after 14 days.
Wong said he would like to assure himself that the Bravo system is as reliable at measuring acid reflux as the nasal catheter.
There also was the question of equipment failure, as in the case of the two prematurely detached capsules, he said. Wong then recalled that catheters dislodge some percentage of the time. "Maybe they are similar in terms of failure," he told UPI.
A second device discussed at the conference blocks acid from backing up into the esophagus in the first place.
Called an expandable hydrogel prosthesis, the device also resembles a vitamin capsule. It is implanted in the submucosa or lining of the esophagus to assist the lower esophageal sphincter in preventing or significantly reducing GERD and the need for medication.
In early results at a multicenter trial in Europe presented at the meeting, the Gatekeeper Reflux Repair System, manufactured by Medtronics Inc., allowed discontinuation of GERD medications in 12 of 14 patients after one month.
Since April 2001, 22 patients in the study were treated with up to six of the expandable capsule-like prostheses, which were placed using an endoscope at the junction of the stomach and esophagus.
Presenting this work at DDW, Dr. Paul Fockens, director of endoscopy at the University of Amsterdam Academic Medical Center, said that since October 2000, nearly 60 patients have received the Gatekeeper system in the United States and Europe.
In general, about two-thirds eventually get off medication, and about 10 percent are able to reduce their use of GERD medications by about half. About 20 percent do not respond.
It does not impede food going down the esophagus. "That was one of our concerns when we started," Fockens said. The Gatekeeper system is under review by the U.S. Food and Drug Administration.
Dr. Glen A. Lehman, of the Indiana University Medical Center in Indianapolis, is involved in the U.S. portion of the trials.
"Basically it's a good idea," Wong said of the Gatekeeper system, explaining that it aids sphincter muscles that are not squeezing as tightly as they should. Before he could use the device clinically, however, he said would like to receive answers to questions about any hazards due to the implants dislodging, as well as answers about any reactions the body might have to the foreign materials used to make the prostheses.
"I think these are great things to study," Wong said. "I want to make sure they objectively study this for two to three years."
Fockens said he intends to study the Gatekeeper system on a couple of hundred patients who would use it for two to five years.
