The Blood Filter Time Bomb: Is There One Inside You?

Date: May 6, 2012      Publication: HealthyWoman from Bottom Line      Source: J. Mark Sloan      Print:

Suppose you needed surgery—for instance, after an accident. Your surgeon might implant a temporary IVC filter in a large vein in your abdomen to help prevent a pulmonary embolism, a potentially fatal condition in which a blood clot travels from the lower body to the lungs. It seems reasonable, given that traumatic injury and surgery both increase the risk for blood clots. And it doesn’t sound like a big deal, since the majority of IVC filters are intended to be removed once the clotting danger has passed or the patient can safely be treated with blood-thinning medication instead.

The problem: Over time, IVC filters (which have spidery legs like the ribs of an umbrella) can break apart…puncture blood vessels…migrate through the circulatory system and lodge in the heart or other organs. They also can actually increase the risk of developing blood clots in the legs—and they can eventually become so deeply embedded that they are impossible to remove. No wonder they are likened to ticking time bombs! Yet according to an alarming new study, for nearly nine in 10 patients who received retrievable (removable) IVC filters, the devices were left in place indefinitely.

The study researchers reviewed the charts of 679 patients who had retrievable IVC filters implanted between 2003 and 2011 at one major US trauma center. Most of the patients had only a temporary need for the filter because after recovery from surgery, clotting risk generally subsides or can be managed with blood-thinning medication. Yet in the months following their hospitalization, attempts were made to remove the filters from only 11% of the patients—and the attempts did not always succeed. For the other 89% of patients, no removal was even attempted!

The likely reason, researchers said, was that the doctors who implanted the devices were seldom the same ones who continued to treat the patients afterward, so there was a lack of coordinated follow-up care. Also, many physicians did not appreciate the importance of removing the filter.

If a doctor ever suggests that you need an IVC filter: Ask whether you can take blood-thinning medication instead. If not, ask when the filter should be removed and who will coordinate that aspect of your care…then be sure to mark your calendar and follow up. Note: Some patients have medical conditions that make it appropriate to receive permanent IVC filters. If this is recommended for you, make certain that you understand the reasons for it and confirm that the filter to be inserted is carefully chosen with permanent placement in mind.

Source: J. Mark Sloan, MD, is an assistant professor in the department of medicine at Boston Medical Center and coauthor of a study on patients with IVC filters presented at a recent meeting of the American Society of Hematology.