The infrequent removal of retrievable IVC filters

On August 9, 2010, the US Food and Drug Administration (FDA) issued a safety communication warning that retrievable Inferior Vena Cava (IVC) filters, which are intended for short-term placement are not always removed once the risk for pulmonary embolism or the contraindication for anticoagulation subside [ ]. The warning was based on the FDA's concerns about the increasing number of device adverse reports involving IVC filters including device migration, embolization and IVC perforation. The FDA encouraged all physicians caring for recipients of IVC filters to consider risks and benefits of filter removal for each patient. However to date, there are no clear or strict guidelines on the proper use and timely removal of IVC filters. The incidence of IVC filter insertion has increased significantly over recent years, especially since the availability of retrievable filters. It is estimated that in 2007, almost 167,000 IVC filters were implanted in the United States compared to only 2000 in 1979, and that in 2012, almost 259,000 filters would be deployed [ ]. This dramatic increase in the utilization of IVC filters was not accompanied by efforts to ensure proper follow up and timely retrieval. To our knowledge, the only long-term randomized controlled trial of IVC filters for the prevention of pulmonary embolism was the PREPIC (Prevention du Risque d'Embolie Pulmonaire par Interruption Cave) study [ ]. A total of 400 patients with proximal deep-vein thrombosis were followed initially for two years. The insertion of an IVC filter in combination with standard anticoagulation was associated with a reduction in the occurrence of pulmonary embolism compared with anticoagulation alone. However, this beneficial effect was counterbalanced by a significant increase in deep vein thrombosis and there was no survival advantage in the combination group. In addition, the lower incidence of pulmonary embolism at 12 days post filter insertion was no longer apparent at 2 years. An 8 year follow up study showed the persistent increased risk of deep-vein thrombosis and no survival advantage with the use of IVC filters [ ]. Given that the benefit of IVC filters appears to be short-term, the option of removing the filter when it is no longer necessary is highly appealing. However, the actual rate of filter removal remains low. In a retrospective study conducted by Gaspard et. al, the rate of removal of retrievable IVC filters was only 3.7% [ ]. Another study looking specifically at trauma patients found that only 20% of filters were removed [ ]. A recent retrospective study performed in a single institution in Australia found that the rate of follow up after IVC filter placement was 39% and the rate of the attempt at retrieval was 26.8% [ ].