Although you can leave an IVC filter in until blood clotting risks subside, temporary devices may be associated with an increased risk of IVC filter complications.

What is an IVC Filter?

An IVC filter is a wire device inserted into the inferior vena cava to prevent clots from reaching the lungs, according to the Memorial Sloan Kettering Cancer Center.

Individuals can be prone to deep vein thrombosis, or clotting in the deep veins of the legs. These clots can move upward towards the upper body through the vena cava, the largest blood vessel in the body. If these clots reach the lungs, they can result in a pulmonary embolism (PE).

A pulmonary embolism occurs when a clot blocks one of the small blood vessels in the lungs. This can make it hard for the body to absorb oxygen from inhaled air – causing a number of life-threatening side effects.

In order to prevent the risk of pulmonary embolism, some patients may be implanted with an IVC filter. These devices are situated in the vena cava and break up large blood clots as they move from the legs towards the lungs.

According to radiologyinfo.org, IVC filters are placed through a minimally invasive procedure which can be done by a radiologist. During the procedure, the IVC filter is inserted through a catheter in the veins of the leg or neck. From there, the radiologist uses imaging technology to guide the filter into place in the inferior vena cava.

Who may need an IVC filter?

Typically, IVC filters are only suggested in patients who cannot be sufficiently treated with blood-thinning drugs. Some patients may be at increased risk for clots, and unable to use medication for treatment. These individuals may need an inferior vena cava filter. Patients with certain conditions, like post-surgery, may require a filter only for a short period of time; they have the filter removed after their risk for blood clots subsides. Other patients may need an IVC filter for a longer period of time – but with the ultimate goal of eventual removal.

Blood clots are likelier in patients who do not move much, because decreased mobility can slow the movement of blood. Johns Hopkins Medicine explains that patients who go travel for long periods may also have an elevated risk of blood clots. Similarly, patients who recently underwent surgery may not be able to move much as they recover. This can increase their risk of blood clots and necessitate the need for an IVC filter during the recovery so a blood clot cannot pose a serious health risk.

In some cases, patients who have suffered deep-vein thrombosis (DVT) and PE conditions may benefit from having a temporary IVC filter implanted.

In contrast, longer-term conditions may also necessitate an IVC filter to help manage patients’ risk for blood clots. Conditions like obesity and old age can limit mobility and put a patient at risk for a blood clot. Some inherited blood disorders can also increase your blood’s likelihood to clot, and other chronic medical conditions may limit your mobility, which in turn can increase the risk of blood clots.

How Long Can You Leave an IVC Filter In?

An IVC filter can be either permanent or retrievable. A retrievable IVC filter is intended to be a temporary solution, in lieu of drugs, that is removed after the clotting risk has decreased.

When a doctor decides to leave an IVC filter in for a period of time, they may use models that have a loop on the end which allows for removal with the intent of future removal. Temporary IVC Filters may include CR Bard’s Recovery filter, G2 filter, and Express filter, as well as the Cook Medical Gunther Tulip filter and Celect filter.

An IVC filter can be removed for several reasons, including the risk of new blood clot formation, fractured filters, or tears to the vena cava. In other cases, a retrievable filter may have outlived its purpose and serves no purpose remaining in the body. If a doctor decides that it isn’t necessary or healthy to leave an IVC filter implanted, they may recommend removal. Ideally, this occurs within six months of insertion.

IVC removal is an outpatient procedure that may use moderate sedation or general anesthesia. During removal, a small incision is made in the jugular vein of the neck. Through this incision, a snare-like tool is guided down the vena cava with imaging techniques where it hooks onto the looped end of the IVC filter. From here, the device is carefully withdrawn.

Penn Interventional Radiology has also developed a “jaws of life” procedure to remove an IVC filter when the standard procedure fails. During this technique, long forceps are used instead of a snare – gently removing the IVC filter from the walls of the vein.

Both techniques have worked to remove retrievable IVC filters, with Penn touting a nearly 100% success rate.

Although there are benefits associated with leaving an IVC filter in only as long as needed, retrievable models may also be associated with increased risks.

Risks of Retrievable IVC Filters

In many cases, retrievable filters may be left in place permanently; however, they are not designed to remain in the body. Leaving a “temporary” filter in the body can reportedly cause filter complications such as fracturing, vena cava perforation, and filter migration.

In some cases, problems with the IVC filters can lead to worsening deep vein thrombosis in the legs, as well as embolization (the blocking of blood vessels), according to PulmCCM.

A study published in JAMA Internal Medicine reviewed outcomes of 952 patients who were given retrievable IVC filters at Boston Medical Center from 2003 to 2011. Fifty percent of these patients were trauma victims. The study revealed that despite all of the patients receiving retrievable IVC filters, only 8.5% had the filters removed.

Deep vein thrombosis reportedly occurred in 8% of patients and pulmonary embolism occurred in 2.5%, despite a filter. One percent of patients reportedly experienced severe complications including migration, embolization, perforation, and fractures.

The authors of the study noted that the rates of IVC filter complications could be much higher than recorded due to the retrospective nature of their methods.