Retrievable IVC filters in the eye of a storm


The US FDA has recommended that implanting physicians and clinicians responsible for the ongoing care of patients with retrievable IVC filters should consider removing the filter as soon as protection from pulmonary embolism is no longer needed. To reduce the risks to patients, the FDA has urged physicians who implant these filters to regularly consider the risk/benefit profile for each individual patient and to give strong consideration to removing these devices from patients who may no longer be at increased risk of pulmonary embolism

Previously, in most places the standard of care regarding IVC filters was to consider placement to be irrevocable unless otherwise indicated.
The warning has been issued on the basis that since 2005, the FDA has received 921 device adverse event reports involving IVC filters, of which 328 involved device migration, 146 involved embolizations 70 involved perforation of the IVC, and 56 involved filter fracture. Some of these events led to adverse clinical outcomes in patients.


SIR response to FDA advisory


The Society of Interventional Radiology has issued a release stating that according to the FDA, use of IVC filters has grown over the years, from 167,000 in 2007 with projections to 259,000 in 2012. “The majority of filters placed are intended to be left in place forever and are not intended to be removed. It should also be noted that even the filters that have the option to be removed may be left in place permanently and the filters on the market have FDA approval for permanent placement,” it says.

“It is worth noting that the SIR’s recommendations closely parallel the current FDA recommendations.

Specifically, the SIR recommends that patients with optional or retrievable IVC filters should be periodically re-assessed as to the appropriateness of leaving the filter in place, and that it is reasonable to consider both the individual patient’s risk of suffering a fatal pulmonary embolism and the risk of late

device complications in making this decision. In patients in whom resumption of blood-thinning drugs is judged likely to be safe and effective in preventing pulmonary embolism, it may be appropriate to remove the filter. It should be noted that there have been no recalls on the filters. The FDA says that it will issue a final statement after completing an analysis on filter problems.”

Michael Lee, Professor Michael Lee, professor, Department of Radiology, Beaumont Hospital, Dublin, Ireland, told Interventional News that  the placement of optional/retrievable IVC filters has exploded over the last ten years.  “Unfortunately, the increased use of these devices has not been matched by level one studies confirming their efficacy.  In particular, the prophylactic indications for optional/retrievable have little supportive data. The FDA is concerned that  IVC filters placed on an intent to retrieve basis are not always retrieved.  The FDA recommends that implanting physicians together with referring clinicians remove the retrievable filter as soon as protection from PE is no longer needed.”

Lee emphasised that the FDA statement is important for two reasons;  It confirms what many IRs have known for some time that there is no perfect  retrievable filter, with many prone to complications and that not all adverse events are reported so there are likely many more of these adverse events. 

“What should we as IRs do?,” he asked. “ I would propose the following; firstly, to fulfil our duty of care we need to consent our patients appropriately (informing patients that the filters are temporary, and will be removed after the risk of PE subsides, and we need to also indicate that it may not be  possible to remove some filters depending on factors such as filter tilt, dwell time etc. Secondly, we as IRs need to take primary responsibility for device removal (this means organising a date for removal in conjunction with the referring physician, at the time of filter placement; patients with retrievable filters should also be seen in IR OPD). Thirdly, as an IR community we need to urgently obtain evidence with regard to retrievable/optional filter placements, for prophylactic indications, in particular. With the latter in mind CIRSE is embarking upon a retrievable/optional filter registry, which will hopefully answer question with regard to current indications for prophylactic placement, dwell times of retrievable/optional filters, adverse events and complications during retrieval,” he added.

William T Kuo, assistant professor, Vascular and Interventional Radiology, Stanford University Medical Center, USA has a similar perspective:  “The FDA’s announcement confirms my suspicion that problems from prolonged filter implantation have generally been underrecognised. In retrospect, I have observed an increase in such filter complications referred to us for treatment over the last several years. These patients have inspired us to develop alternative retrieval methods for embedded filters in order to reduce morbidity, alleviate anxiety, and reduce further risks from prolonged filter implantation. Although many filter issues have resulted from poor follow-up, I have also seen filter-related problems arise in patients with close monitoring. At the very least, I believe the interventionalist who inserted the filter must be accountable. For those of us who have established IVC filter clinics, the FDA’s recommendation reaffirms our commitment to these crucial efforts.”