Permanent IVC Filters
Originally, IVC filters were designed and implanted to be permanent. However, this strategy is far less popular nowadays. In the early 2000s one of the manufacturers came up with the idea of selling a filter that could be placed temporarily with the option of being left in for life. Many of the permanent manufacturers jumped on board as it appeared doctors were receptive to this idea.
Temporary IVC Filters
Filters that are implanted with the objective of being explanted are called temporary, or optional IVC filters. The reason for the term “optional” is that they can be be removed. Typically, these are implanted when there is only a temporary risk of blood clotting.
Temporary vena cava filters are an enticing strategy for patients who, contemporaneously, are at high risk of VTE events and have contraindications to blood thinners. Thus, the filter can act as a bridge until VTE risks decrease or the contraindications subside. Such usage typically is now considered for prophylactic purposes, though any such use would be “off-label.” This means that a manufacturer cannot market a medical device for a use that is not a “labeled” (i.e., cleared or approved), for use by the Food and Drug Administration (“FDA”).
More and more, hospitals in the United States use vena cava filters as a prophylactic measure in trauma patients. This is due to these patients having conditions that place them at an increased risk of experiencing a VTE event, yet contemporaneously putting them at risk for bleeding from associated brain or abdominal organ injuries.
Many temporary filters are implanted with no particular plan to remove them. Naturally, there are risks involved with implantation and removal, and complications associated with IVC filters increase the longer they remain in the body. In July, 2015, the FDA issued a WARNING to Bard that the device it sold to remove the vast majority of its filters had been placed on the market without FDA approval. This almost unprecedented act of placing a medical device on the market and its use on thousands of patients is almost unheard of in the annals of widely distributed devices. This surreptitious act by Bard has led to an investigation by the FDA that remains ongoing.
Another alarming issue regarding IVC filters deals with “off label” or non FDA approved usage on patients by implanting surgeons. According to a well-documented October 2013 study published in the Journal of Vascular Surgery: Venous and Lymphatic Disorders, scores of American-based surgeons have implanted IVC filters off-label by putting them in patients that, although have blood clot issues, have never been diagnosed with PE and have not been determined to have issues with blood thinners.
According to the study, “The widespread off-label use of IVC filters outside of FDA-cleared indications is believed to account for more than 50% of IVC filters implanted in the United States, and this percentage is likely to increase.” The study continued to detail the problem by stating, “According to the most recent IVC filter consensus panel, 50% or fewer of retrievable IVC filers are ever removed, although it is unknown whether they were implanted for transient high risk of PE or for the management of chronic venous thromboembolism.”
So, although many retrievals prove successful, explants of these temporary filters are typically not scheduled and are never planned to be removed. One possible reason to explain this is that the patient had ongoing indications suggesting the filter should remain in the body.
Nonetheless, On May 6, 2010, the FDA released a Safety Communication Update to its 2010 Initial Communication titled Removing Retrievable Inferior Vena Cava Filters: FDA Safety Communication. This communication included a recommendation, which was addressed to doctors who implant IVC filters as well as any staff responsible for the ongoing care of patients with IVC filter. It stated,
The FDA recommends that implanting physicians and clinicians responsible for the ongoing care of patients with retrievable IVC filters consider removing the filter as soon as protection from pulmonary embolism is no longer needed.
The FDA encourages all physicians involved in the treatment and follow-up of patients receiving IVC filters to consider the risks and benefits of filter removal for each patient. A patient should be referred for IVC filter removal when the risk/benefit profile favors removal and the procedure is feasible given the patient’s health.
Food and Drug Administration
Removing Retrievable Inferior Vena Cava Filters: FDA Safety Communication
The reason for the FDA update stems from reports of adverse events and problems associated with IVC filters.
According to Dr. Christopher J. Kwolek, IVC filters should be implanted with plans to be removed, and 95% can be removed with standard explantation techniques. These removals should be planned with aggressive follow-up procedures because, although extreme techniques exist and can be successful, many filters can become permanent. See Temporary IVC Filters – Why and When Should They Be Removed? Techniques for Difficult IVC Filter Removal, Christopher J. Kwolek, MD, Division of Vascular and Endovascular Surgery, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
