CHICAGO — Filters that stop blood clots from reaching the lungs can move or break and cause life-threatening problems for patients, the government and a medical journal report said yesterday.
In an advisory to doctors and patients, the Food and Drug Administration said it has received more than 900 reports about problems with such filters since 2005. Problems can arise when filters are left inside veins too long. The devices can shift, and pieces can break off, drift through the bloodstream and perforate vital organs, including the heart, according to the FDA’s website.
The filters are inserted inside a large abdominal vein and have spidery metal legs to stop clots from traveling to the lungs. Some are permanent, but many are for short-term use and are removable.
The FDA says doctors should consider removing filters if a patient’s risk of clots subsides.
“It’s thought that too many retrievable filters stay in permanently because patients are lost to follow-up,’’ or doctors don’t know problems can occur when the devices are left in long-term, Dr. Bram Zuckerman, an FDA official, said yesterday. About 30,000 filters are implanted each year. Several brands are sold, and Zuckerman said problems have been seen with all retrievable filters. Some reports to the FDA involve patients who died , but Zuckerman said blood clot patients often are very sick to begin with so it’s unknown if filters played a role in any deaths.
A report that appeared online yesterday in the Archives of Internal Medicine involved 80 patients at a hospital in York, Pa., who received filters made by a division of C.R. Bard Inc., a New Jersey company. Overall, 16 percent of the patients had a filter break. Among patients who had an older version, 25 percent had a filter break followed by material drifting away — an astounding rate, said Dr. Rita Redberg, the journal’s editor.