Less than five years ago, NBC News published a series of articles on IVC filters and the complications they can cause those who have undergone an implant. One of the folks they interviewed explained that four months after she was implanted with an IVC filter, she developed a severe headache and passed out. Within “two seconds of being in the ambulance, I started flat-lining . . . my family was notified” and “the priest was brought in.” During an emergency open-heart surgery procedure, surgeons were able to successfully remove a broken piece of the IVC filter that had migrated. Not all patients are this lucky.

In a separate interview, a man described how his mother had been implanted with an IVC filter and that “everything was fine” when she was discharged from the hospital. Sadly, his mother died within a week after returning home from the hospital. These stories are not isolated incidents. In fact, there are hundreds, if not thousands, of people in the United States who were implanted with an IVC filter and the result quickly led to life threatening complications and even death. 

The focus of the NBC News piece was on C.R. Bard and its Recovery IVC filter device. NBC made the following discoveries during its investigation:

• After the problems with the Recovery began, Bard hired public-relations giant Hill and Knowlton.
• Hill and Knowlton circulated a crisis management plan to Bard management, warning that “unfavorable press” could damage stock prices and ruin reputations.
• The company also retained an outside doctor to conduct a confidential study, which was obtained by NBC News.
• The consultant found the Recovery filter had higher rates of relative risk for death, filter fracture and movement than all its competitors.
• “Further investigation . . . is urgently warranted,” the doctor wrote.
• But even as death and injury reports were climbing, the company decided not to recall the Recovery.
• Instead, Bard sold about 34,000 of them for nearly three years before replacing them with a modified version with a new name, G2.

C.R. Bard, along with Cook Medical, are two device manufacturers currently involved in litigation over their IVC filters. Each manufacturer has over 5,000 lawsuits filed against them in their individual federal court proceedings. periscopegroup.com/IVCfilter

What is an IVC filter?

As one doctor has described, “an IVC filter is a metal umbrella or metal scaffolding, which is placed in the inferior vena cava to filter blood flowing from the legs to the veins . . . designed to capture blood clots that may develop in the legs and dislodge, keeping them from migrating and going to the pulmonary artery.”

Permanent Filters and Retrievable Filters

Currently, there are two varieties of filters that doctors use in patients: (1) permanent filters, and (2) retrievable filters. Permanent filters are typically reserved only for use in patients with a high risk of a recurrent blood clot AND that patient CANNOT tolerate anticoagulation therapy (people whose bodies have an adverse reaction to blood thinners OR have recurrent pulmonary embolisms despite being on anticoagulation therapy). Retrievable filters are not the most commonly used, with a design similar to that of permanent filters, but built to be retrieved within several months of implant.

When Did IVC Filters Get On the Market And What Do We Know About Their Safety and Effectiveness

In the United States there are over 300,000 people who experience pulmonary embolism (“PE”). In 1973, Dr. Kim-Ray Greenfield inserted the first IVC filter to prevent PE. The use of these filters did not increase until the late 1990s when retrievable filters were developed. There has been an exponential increase in the use of IVC filters over the past two decades. In fact, an estimated 2,000 IVC filters were placed in 1979, with a 25-fold increase to nearly 50,000 filters in 1999. More recent studies have shown that approximately 17% of all patients in the United States diagnosed with venous thromboembolism (“VTE”) are implanted with an IVC filter, which is 25 times higher than the usage rates in Europe. A significant portion of the rise in filter implants came after the late 1990s and early 2000s when the United States Food and Drug Administration (“FDA”) approved the use of retrievable IVC filters. periscopegroup.com/IVCfilter

Currently, there is very limited evidence-based literature to support the high utilization rates of IVC filters. To date, there are only two randomized prospective trials that have investigated the safety and effectiveness of these filters to prevent PE. In both trials the patients were treated with anticoagulants, which limited the interpretation of the data acquired because the current clinical role for IVC filters is focused on patients who have adverse reactions to anticoagulation.

Between 1985 and 2000, 43% of articles listed on PubMed were focused on filter-related complications. From 2000 to 2017, the number of articles on IVC filter complications increased to 57%. Generally speaking, filter complications can be divided into three categories: (1) procedural complications, (2) delayed complications, and (3) complications associated with filter retrieval.

• Procedural Complications
• • Venous Access Site
  • Malposition
  • Defective Filter Deployment

• Delayed Complications
• • Migration
  • Thrombosis
  • Filter Fracture
  • IVC Perforation
  • Pulmonary Embolism
  • Device Infection

With respect to retrieval complications, long-term results are lacking. Prompt removal of filters as soon as indicated is recommended, but research and studies show that this is not typically the case in the United States.

In 2010, as a result of increasing reports of retrievable filter-related complications (in connection with very low filter retrieval rates) the FDA issued a safety communication placing the responsibility of filter retrieval on implanting physicians once protection from PE was no longer needed. This safety advisory was further renewed in 2014. The optimal retrieval window for retrievable filters is between twenty-nine (29) and fifty-four (54) days following implant. One study reviewing data between 2012 and 2016 found that nearly 66% of retrievable filters that were placed were never retrieved. Additionally, a systematic review of 37 studies (these 37 studies collectively reviewed the outcome of 6,834 patients) found that retrieval rate did not exceed 34%.

So Where Does This Leave Us For 2019?

The American College of Chest Physicians (“ACCP”) recommends placement of an IVC filter ONLY in patients with an acute deep vein thrombosis (“DVT”) and who cannot tolerate anticoagulation due to active bleeding or high risk of bleeding. As for the filters themselves, the verdict is still out on their use, and if possible, studies show that simultaneous use of anticoagulation is recommended as well.