IVC Filter Complications

Blood clot filters are devices that are sometimes placed in the largest vein in the abdomen (IVC) to prevent large blood clots formed in the leg veins from traveling into the lungs. A 2022 report published in the Journal of Vascular Surgery noted that IVC filter complications were between 1.8% and 3.1%. In order to reduce the risk of potential complications, experts recommend removing the filter as soon as the device is no longer needed and preferably within 2-3 months after implantation.

Although advancements in filter design have attempted to reduce the number of problems, newer filters have not necessarily led to decreased complications. Also, since many patients with filters are never followed, they may suffer “silent” complications, so it’s unknown exactly how prevalent they are. Most physicians are not trained to recognize filter-related complications, so the problem may go unnoticed and undiagnosed for years.

Nevertheless, when patients are properly selected for IVC filter insertion, the device may help “prevent potentially fatal PE events with a very low risk of complications” according to a 2016 analysis in the journal of Cardiovascular Diagnosis & Therapy, but these patients must receive proper follow-up care to remove the filter when no longer needed, according to two FDA Safety Alerts published in 2010 and 2014.

In 2010, due to rising filter-related complications reported to its database of adverse events, the FDA issued a Safety Alert on IVC filters. Complications vary and are categorized by type, with certain complications overlapping into multiple categories.

Dr. William Kuo, an interventional radiologist and Professor of Interventional Radiology at Stanford University School of Medicine, helped pioneer the field of advanced IVC filter retrieval, including the use of excimer laser to remove embedded devices that cannot be safely removed using standard methods. He and his team at Stanford have performed thousands of advanced filter retrievals.

“I see the whole spectrum of IVC filter complications — filter components can penetrate through the vein and cause pain, while some pieces can break, migrate and cause other problems. An old filter can also cause scarring in the vein leading to vessel occlusion, debilitating leg pain with swelling and greater risk for blood clots,” Dr. William Kuo, an interventional radiologist and Professor of Interventional Radiology at Stanford University School of Medicine, told Drugwatch.

“Even if patients have not yet suffered these complications, the knowledge that they could develop in the future creates real anxiety among these patients,” he said.

Depending on the type of complication, many patients may experience no immediate symptoms while others may develop immediate pain or severe problems years later. In some instances, the side effects can be painful and dangerous.

“It’s like a knife being pushed into your stomach,” one patient told a television reporter about the experience of having her IVC filter twist and puncture the walls of the vessel where it had been implanted three years earlier.

Clare Austin of South Florida said surgeons had to make an incision of approximately 10 inches in her belly to remove the filter.

If a filter has been implanted for several years, patients should initially consult with their local doctor to assess the status of their device. It could be evaluated with routine x-rays or a CT scan, and they should at least be followed by a local physician. If there is any uncertainty regarding possible complications, then the case should be reviewed by a knowledgeable specialist.

“For patients with an indwelling device, it is important to check in with a physician who can at least identify what type of device was implanted. Recent X-rays should be reviewed to identify the filter type, assess for filter integrity, and examine for other complications. A specialist can also help determine the need and feasibility of potential removal versus ongoing follow-up,” Dr. Kuo said.

Newer techniques have been developed that allow most filters to be removed using minimally-invasive methods (small < 1 cm incision) with quick recovery times; thereby avoiding the need for large painful incisions or open vascular surgery.

To place the filter, a doctor will use a small catheter inserted through the skin into a vein in the neck or groin and then thread it to the inferior vena cava in the abdomen, using ultrasound and X-ray guidance. This procedure is referred to as percutaneous.

Major complications related to filter insertion are very rare and happen less than 1% of the time. Most complications are minor and include small bleeding or a small blood clot at the access site. Rarely, there may be accidental puncture of an adjacent artery. Some patients may develop an infection at the insertion site.

Short-Term Placement Complications

Possible procedural risks include the guide wire penetrating the vein as well as bleeding, clots or infection of the insertion site. People can also develop reactions to the contrast agent used during the procedure that can lead to kidney dysfunction, but this is rare.

A rare complication is the formation of an arteriovenous fistula, or AVF, which involves an abnormal connection between an artery and a vein. The reported incidence of this complication is 0.02%.

As with most percutaneous procedures, those that are made through the skin, filter placement also carries the risk of developing a collapsed lung (pneumothorax) or a collection of blood in between the chest wall and lung (hemothorax). Other complications can include the accidental introduction of air into a blood vessel, called an air embolus, and heart rhythm abnormalities.

Access Site Bleeding and Misplacement

The rate of bleeding at the access site is estimated between 6% and 15%, but significant bleeding that would require a transfusion or surgery is rare. Patients can also develop blood clots at the insertion site. This is more common in patients who are hypercoagulable, meaning they have blood that tends to clot too much.

In rare instances, medical professionals have incorrectly oriented the filter. In one case, a filter was accidentally placed upside down and had to be retrieved. In some cases, Filters have even been placed in the wrong blood vessel.

Other complications relate to problems with the filter itself. For example, the filter might fail to completely open, it may tilt or be placed in the wrong location. The filter may migrate to another location in the body. Some filters will simply fracture over time under normal repetitive stresses that occur naturally occur within the body.

IVC Filter Migration

Medical professionals consider a filter to have significantly migrated if it moves two centimeters or more from the initial location. This can happen for several reasons, including the vein being too large to accommodate the filter.

Overall, filter migration risk is estimated at less than 1%. Researchers say 90% of migration incidents happened more than 30 days after placement.

When migration into the cardiopulmonary system happens, it can be fatal, and it requires immediate intervention. This may include attempted percutaneous retrieval, but if that is not feasible, then open-heart surgery is required.

Sometimes the filter is defective and fails to open completely. This also can happen for other reasons, including an error on the part of the doctor who places the filter. A 2016 study in the journal Cardiovascular Diagnosis & Therapy said this failure to open happens between 0.7% to 13.9% of the time. And with one type of filter — the titanium Greenfield filter — can happen in as many as 71% of cases. When this happens, the filter’s performance can be decreased by as much as 80%, especially for catching smaller clots.

Boston Scientific recalled 18,000 Greenfield IVC filters in December 2005. The company said a defect could cause cardiac or pulmonary embolism. It also recalled two lots of filters for possible blood vessel damage in August 2005. Boston Scientific was the first company to issue an IVC filter recall. Since then, Bard, Cordis and B. Braun have recalled more than 63,600 IVC filters for packaging and labeling errors.

Another possible complication is called caval thrombosis, or blood clotting in the vena cava. Rates have been estimated to range between 2% and 30%.

When there are symptoms, they include pain and swelling in the lower extremities. The cause isn’t known, but can be related to the fact that some patients already have a higher risk of clotting, and this may further increase after placement of a foreign body, such as a filter, in the vena cava. In these patients, even if clots are captured in the filter, their body may have trouble breaking down the clot, and the clot can grow even larger.

Filter Fracture and Perforation

Filter fracture may occur early or late depending on the filter type, but it is usually seen in filters that have been in place for more than a year. Researchers have found that the filter may fatigue and fracture over time under normal repetitive stresses that occur naturally occur within the body.

Therefore, promptly removing filters after they are no longer needed can avoid this complication.

In one study, researchers looked at 80 patients who had two particular brands of filters placed in them between 2004 and 2009, the Bard Recovery and the Bard G2 filters. A total of 13, or 16% of the patients, had at least one of their filters’ struts fracture. In five cases, the strut had lodged in the patients’ hearts. Three of the patients had life-threatening conditions.

Sometimes the filter perforates the vein. This happens more often with retrievable filters that have been left in place longer than intended. Serious, but rare cases, have involved perforation of the duodenum, the aorta, and the renal pelvis.

If a patient with a filter experiences non-specific abdominal or back pain, physicians should suspect possible filter component penetration.

Pain experienced by patients with an IVC filter may be related to the filter. Some filter-related complications causing pain include IVC penetration, filter component embolization, and/or a blocked filter resulting in severe leg pain.

Sometimes, a broken filter piece may cause pain where it lands including in the upper abdomen or chest. A filter penetration in one location may also cause referred pain in a region higher or lower than the original filter position. Therefore, pain associated with IVC filter complications can affect the chest, abdomen, pelvis, and legs.

Abdominal or Back Pain from Perforation or Migration

Abdominal or back pain associated with an IVC filter is typically due to penetration through the blood vessel wall, impingement against nearby nerves, and/or penetration into adjacent organs. Migration of filter components or referred pain may affect other areas of the body.

Perforation and migration account for about 22% and 20% of all reported complications, respectively.

A case report in 2016 involved a 49-year-old woman who suffered from severe abdominal pain and previous back pain. Her other symptoms included nausea, anorexia, non-bloody vomiting and loose stools (diarrhea). A CT scan showed migration of all four struts of her IVC filter.

The struts had penetrated a nearby blood vessel (the aorta), part of the spine, muscle located adjacent to the lower spine and pelvic region, and tissues located between various organs and the abdominal wall.

Although open surgery was needed to remove the IVC filter and repair the patient’s injuries in the past, newer minimally-invasive techniques can now achieve retrieval in most patients without the need for invasive open surgery.

Leg Pain Related to Blockage

Leg pain from the device is often due to a blockage. When several clots become trapped in the filter, clot formation down the IVC can cause painful debilitating swelling in the legs.

Other signs and symptoms of a problem might include darkening of the skin and ulceration in the lower extremities.

Patients may have difficulty identifying the cause of their leg pain. Any pain that is severe or worsens suddenly should be immediately evaluated by a doctor as it could represent new blood clots or deep vein thrombosis (DVT).

When a filter strut breaks loose, makes its way through the bloodstream, and enters into the heart or lungs, this is called embolization. These patients can suffer acute chest pain similar to a heart attack.

Adverse event reports submitted to the U.S Food and Drug Administration (FDA) between 2005 and 2010, included 146 reports of embolization out of 921 total reports.

Embolization of IVC filters to the heart and lungs can have serious and sometimes deadly consequences. Signs and symptoms of this condition might include acute chest pain, abnormal heart rhythm, shortness of breath, feeling faint and loss of consciousness.

A 2008 case study in the Texas Heart Institute Journal describes a 69-year-old patient who was implanted with an IVC filter which ended up moving to the right ventricle of his heart. His primary symptom was an abnormal life-threatening heart rhythm known as ventricular tachycardia.

After the device was removed, he developed a leaky tricuspid valve in his right heart chamber. His doctors believed the device had become entangled in the valve, which sustained damage when the device was removed.

In some cases, open heart surgery may be needed either to remove the filter or repair damage caused by IVC filter embolization to the heart.

Patients with IVC filters have a risk of developing deep venous thrombosis (DVT) – a blood clot in lower-body vein.

The risk doubles two years after a filter is placed. The incidence of this complication has been estimated to be as high as 43%.

This is another reason why experts recommend removing the IVC filter as soon as it’s no longer needed.