IVC Filter Removal

IVC filters are self-expanding metallic devices designed for implantation within the inferior vena cava, or IVC—the largest vein in the abdomen. The filters are inserted through a catheter via a small incision. The filters are designed to catch large blood clots and prevent them from migrating into the lungs. Once trapped, the patient’s body has more time to dissolve them naturally or in conjunction with blood thinning medication.

Older IVC filters were meant to be left in place permanently, but data has shown that filters left in place may lead to complications. A 2022 report published in the Journal of Vascular Surgery noted that IVC filter complications were between 1.8% and 3.1%. Therefore, newer retrievable type IVC filters were intended to address these issues. According to the FDA and Radiological Society of North America IVC filters should be removed once the danger of a life-threatening clot is over.

Although the procedure to remove the filter is also minimally-invasive, removing the device may be challenging especially after prolonged dwell times. Excess scar tissue may form around the filter components increasing the risk of procedure-related complications such as bleeding and/or blood clotting. Filter fractures may occur and/or existing filter fragments may migrate during the retrieval procedure. In some cases, the filter may become further deformed and embedded in the blood vessel wall requiring a more advanced retrieval procedure at a specialized center.

Many patients have been told that their indwelling filters cannot be safely retrieved or that removal is not possible without invasive open surgery. However, due to research in the field, a variety of minimally-invasive treatment options now exist for most filter patients.

“Patients should educate themselves and be aware they might be candidates for advanced filter removal, without the need for invasive open surgery if standard methods fail. These minimally-invasive retrieval techniques are available at centers that specialize in advanced filter removal,” Dr. William Kuo, an interventional radiologist at Stanford Health Care, told Drugwatch.

Dr. Kuo pioneered advanced laser-assisted IVC filter removal—a minimally-invasive technique that can be used to remove embedded IVC filters without the need for open surgery.

Doctors remove retrievable filters in a way similar to how they implant them—using a catheter inserted through a small skin incision less than a centimeter long.

Health care providers first inject contrast or X-ray dye through the catheter to perform an angiogram in the vessel. This is important to make sure there are no large blood clots within the device prior to removal.

A snare device similar to a lasso is then inserted through the catheter and used to catch the filter hook. The catheter is then advanced over the filter in order to collapse it like a folding umbrella.

The filter is then removed through the catheter followed by removal of the catheter itself.

What to Expect Before Removal

The FDA recommends that retrievable IVC filters should be removed once the danger of a pulmonary embolism has passed.

If a patient with pulmonary embolism (PE) or deep vein thrombosis (DVT) cannot resume blood thinners right away, then the IVC filter may be left in place until the patient has recovered from their major illness or bleeding risk.

Ideally, the filter is not removed until the patient can safely resume taking blood thinners to prevent further blood clots

Patients Checked Before Procedure

In the weeks leading up to filter removal, doctors reassess their patient’s need for the filter along with potential complications that occasionally arise from the filter itself.

Preparing for Removal

Before undergoing an IVC filter removal, patients should go over their medical history, including any current illnesses or medical conditions, with their doctor. Patients should report all medications and herbal supplements they are taking as well as any allergies, especially to drugs or anesthesia.

Any surgery carries risks. These can include infection or reaction to the drugs used during the procedure. In addition, IVC filter removal procedures carry their own complications.

Removal Failure

If the filter has scarred into the blood vessel wall, removal may not be possible using standard methods. These patients may be considered for advanced filter removal after further evaluation at a specialized center.

Some centers offer advanced laser-assisted removal that may safely remove these devices using the same small skin incision.

In this procedure, a laser catheter is inserted through the outer catheter and used to gently ablate or remove scar tissue around the filter. This allows the filter to be freed, captured and removed using lower force.

Studies have shown that the longer an IVC filter remains in place, the more difficult it is to remove, and the greater the risk of filter-related complications.

“A filter sitting in a vein for a long enough time may cause scar tissue to form around it; eventually, the device anchors can become ingrown and firmly embedded within the vessel,” Dr. Kuo said.

Over time, filter components can also perforate through the vein wall while other parts can fracture. These broken pieces are at risk of migrating to the heart, lungs and other organs where they may cause damage.

Embedded IVC Filters

In many cases, IVC filters left in place too long, over several months to several years, cannot be safely removed using standard methods because they have scarred into the walls of the vein.

“Unfortunately, this complication rate can be really high,” Dr. Kuo told Drugwatch. “This may occur in up to 20 to 40 percent of cases depending on the dwell time and filter type.”

This has led to further research on advanced filter retrieval methods.

Illinois doctors Benjamin Lind and Hector Ferral documented a case in which they successfully removed a Cook Medical Günther-Tulip IVC filter more than nine years after it was implanted. The device had shifted, penetrating the wall of the vein and perforating the patient’s small intestine and part of her urinary tract.

Extensive Removal Planning

Advanced IVC filter retrieval may be offered when the standard technique — using a snare and catheter to sheath the filter fails.

“Many patients and their local doctors remain unaware that advanced filter retrieval techniques now exist that may allow successful minimally-invasive retrieval without the need for open surgery,” Dr. Kuo told Drugwatch.

Dr. Kuo pioneered a variety of advanced retrieval techniques including use of excimer laser to remove embedded IVC filters.

“The idea behind using excimer laser is to gently and precisely deal with scar tissue that forms around an embedded filter,” Dr. Kuo said.

The laser emits concentrated, ultraviolet light at its target, firing in bursts as short as one-billionth of a second. In eye surgery it may be used to vaporize part of the cornea’s surface, reshaping the eye to correct the patient’s vision.

In advanced filter retrieval, the same concept allows very precise removal of scar tissue around the filter 50-100 microns at a time. These are extremely thin layers; there are about 25,400 microns in an inch. Ideally, once the scar tissue is removed, the filter becomes retrievable.

“The excimer laser technique is a major advancement that has allowed us to safely remove a variety of chronically implanted filters that were previously considered irretrievable,” Dr. Kuo said

Advanced IVC filter retrieval may be offered when the standard technique — using a snare and catheter to sheath the filter fails.

“Many patients and their local doctors remain unaware that advanced filter retrieval techniques now exist that may allow successful minimally-invasive retrieval without the need for open surgery,” Dr. Kuo told Drugwatch.

Dr. Kuo pioneered a variety of advanced retrieval techniques including use of excimer laser to remove embedded IVC filters.

“The idea behind using excimer laser is to gently and precisely deal with scar tissue that forms around an embedded filter,” Dr. Kuo said.

The laser emits concentrated, ultraviolet light at its target, firing in bursts as short as one-billionth of a second. In eye surgery it may be used to vaporize part of the cornea’s surface, reshaping the eye to correct the patient’s vision.

In advanced filter retrieval, the same concept allows very precise removal of scar tissue around the filter 50-100 microns at a time. These are extremely thin layers; there are about 25,400 microns in an inch. Ideally, once the scar tissue is removed, the filter becomes retrievable.

“The excimer laser technique is a major advancement that has allowed us to safely remove a variety of chronically implanted filters that were previously considered irretrievable,” Dr. Kuo said