NEW YORK (Reuters) -- A tiny, new, temporary filter, placed in veins in the lower body, can catch dangerous blood clots before they make their potentially fatal journey to the lungs. Researchers think the technology will be especially effective in saving the lives of accident victims.
"A patient who must lie flat for many days because of an injury tends to form blood clots, especially in the legs," said Anthony Venbrux, an associate professor of radiology at Johns Hopkins Hospital, where the new device was recently first used. "These clots are like time bombs," Venbrux explained. "If they break off from where they form and get to the lungs, they may block off the blood flow and kill the patient."
Such clots, or 'emboli', occur in over 20% of accident victims. They are the third most common cause of death in those surviving a full day after a serious accident, according to Johns Hopkins experts.
Heparin, an intravenous drug often used to prevent clots from forming, cannot be used if the patient is suspected to have internal injuries that could bleed, said Venbrux.
Venbrux used the new technique for the first time on a 35-year-old motorcycle-accident survivor. The patient had suffered a broken pelvis and been bedridden for the two weeks before the procedure.
The filter was threaded through a catheter inserted into the neck, and guided into the inferior vena cava, a large vein that returns blood from the lower part of the body, and empties directly into the heart. Once put in place, the filter opens in a fan of tiny fingers, allowing blood flow, but obstructing clots.
"We put the filter below the level of the kidneys to prevent the clot from going to the kidney, as well as to protect the lungs," said Venbrux.
Upon x-ray, doctors discovered that the filter had, indeed, trapped a potentially fatal clot on its way to the patient's lungs.
At a later date, the filter can be removed by pulling the catheter out from the incision in the neck where it was originally placed, say physicians.
Permanent filters have been used in the past, say the Johns Hopkins researchers, but because body tissue forms a tight seal around them, removal requires major surgery.
The new filter, called Tempofilter, is manufactured by the B. Braun Celsa Company.
