Not all IVC Filters Are Permanent: Advanced Techniques Retrieve Hard-to-Remove Filters

March 12, 2021
Dr. Noor Ahmad

Dr. Noor Ahmad and his interventional radiology colleagues have expertise in advanced IVC filter removal.

Interventional radiologist Dr. Noor Ahmad has a message for patients with IVC filters and the physicians who treat them: IVC filters can and should be retrieved, no matter how long they have been in there, as long as the patient no longer requires the filter.

"Many people think there's nothing to be done about a filter that's been in for a long time," says Dr. Ahmad, assistant professor of radiology at Columbia University Irving Medical Center. "But there are centers like Columbia, where we've been trained in advanced techniques, and we can take them out safely."

Inferior vena cava (IVC) filters are tiny metal devices—resembling the frame of an umbrella—that doctors place in a major vein called the inferior vena cava to catch blood clots. IVC filters are sometimes used to treat deep vein thrombosis (DVT), a condition in which a clot develops in one of the deep veins of the leg. DVT is potentially life-threatening because the clot can break free and travel through the bloodstream to the lungs, where it can block the arteries in the lung and potentially cause sudden death, a condition called pulmonary embolism.

Both the design and the use of IVC filters have evolved over the past few decades, leaving large gaps in knowledge among patients—who aren't always aware of the risks that come with leaving a filter in—and sometimes their physicians.

"IVC filters were initially designed to stay in and I think that mantra has stuck," says Dr. Ahmad, explaining that when newer filters are placed today, most come with protocols for follow-up and removal within six months. "The biggest hurdle is awareness."

Since he joined Columbia Radiology one year ago, Dr. Ahmad has devoted a portion of his time to educating physicians at the medical center about the risks of leaving IVC filters in and the expertise Columbia's interventional radiologists have with complex removals.

Dr. Ahmad emphasizes that most filters should be retrieved before any complications occur. "The number one symptom is that patients don't feel any symptoms," he says. "Many patients forget that they have a filter in their bodies until it becomes a big problem."

Xray of IVC filter and grasping device

A grasping device is one of the tools used by interventional radiologists to retrieve hard-to-remove IVC filters, as shown in this X-ray.

When IVC filters are left in for more than six months, clots and tissue may form around the filter, which is the body's way of reacting to a foreign body. Eventually, clots can block the vein and cause significant swelling in both legs, making it difficult to walk. Older filters have other potential complications, including pieces that break off and travel to the heart or lungs, resulting in arrhythmias or pulmonary embolism.

Simple retrieval techniques do not always work on these older filters, but that doesn't mean there's nothing to be done. “Often patients see us in consultation who have been told by their doctors that their filters either can't come out or would require major surgery to remove. This isn't true,” says Dr. Ahmad. A center with expertise in advanced filter retrieval will have the tools needed to remove all IVC filters without major surgery, along with physicians trained to perform these more advanced procedures. Advanced techniques include the use of lasers to break up tissue that forms around the filter as well as special grasping devices that can pull the filter out. "We call them the 'jaws of life'," says Dr. Ahmad.

Patients who have IVC filters can schedule a consultation with an interventional radiologist to advise on the best course of action. All IVC filter retrieval procedures are performed as an outpatient, under image guidance. "The patient goes home with a Band-aid at the end of the day," says Dr. Ahmad.