New Treatment for Gallstones Success in Tests : Medstone Method Called Suitable for Some Patients
A new method developed by Medstone International Inc. of Irvine for removing gallstones without surgery has been proven successful in recent tests involving more than 200 patients, one of the physicians leading the tests said Thursday.
Dr. David Vanderpool of Baylor University Medical Center in Dallas said that Medstone’s method is suitable for about 25% of all gallstone patients.
Of those who have received the treatment, an initial survey of 223 patients indicated that about 90% remained stone-free 6 months afterward, Vanderpool said.
Gallstones are painful obstructions that form in the gallbladder or bile duct. Vanderpool said that about 500,000 patients require gallstone removal every year in the United States. The most common treatment is surgical removal, which typically requires a 1-week hospital stay.
Lithotripter Device
The method developed by Medstone involves use of a device called a lithotripter, which sends highly focused shock waves through body tissue into the gallbladder. The shock waves release their energy into the gallstones, causing them to crumble. The patient is then given oral medication that causes the stone fragments to dissolve and pass from the body.
Of the 223 patients who received the Medstone treatment, two required surgery to relieve obstructions caused by the stone fragments. Five others later had their gallbladders removed surgically because of “poor fragmentation.”
The clinical tests began about 15 months ago at 10 centers across the country after the U.S. Food and Drug Administration approved clinical trials of the procedure. Medstone has now applied for FDA approval to market the technology.
Medstone already has received FDA approval to market its lithotripter device to remove kidney stones, which are smaller than gallstones.
The test results indicate that the technology holds great promise for gallstone removal, said Jim McCamant, editor of the Medical Technology Stock Letter in Berkeley.
But McCamant said it might not be long before other companies have similar products on the market. “Patent protection will not be great with this technology,” McCamant predicted.
Could Get an Early Start
One industry executive said that Medstone could be the first company to win FDA marketing approval, which would allow it to establish itself before the market becomes competitive.
On Wednesday, clinical results involving the 223 patients who participated in the recent tests are to be presented in Vancouver, Canada, by Vanderpool and other physicians. In addition, the results are scheduled for publication in a leading medical journal.
Medstone had scheduled a press conference this week to discuss the study results, but FDA officials told the company not to hold the conference, a Medstone official said.
McCamant said that the company might hurt its chances for quick approval if it creates the impression that it is publicly touting its technology.
