In a recent study testing the safety and effectiveness of inferior vena cava (IVC) filters used to protect against pulmonary embolism (PE), researchers have concluded that the device fell short of criteria required to deem the device safe and effective.
A pulmonary embolism is a severe condition that is often fatal. It occurs when a blood clot forms in a lower extremity and embolizes to the heart or lungs. Anticoagulation medication is used for treatment of recurrent embolism, but not all patients can tolerate the drugs.
A vena cava filter is often used in place of anticoagulation medication. It is a cage-like device that is inserted into the inferior vena cava, the largest vein in the body, and is designed to catch blood clots in the legs of the cage, preventing them from reaching the heart or lungs. Versions of the vena cava filter have been used as early as the 1960s.
More recently, temporary IVC filters have been introduced, such as the Recovery filter, G2 and G2 Express made by C.R. Bard. The OptEase is a temporary filter made by Cordis, a subsidiary of Johnson & Johnson, and the Gunther Tulip and Celect models are made by Cook Medical. The devices are created to be retrievable, and per the U.S. Food and Drug Administration (FDA), should be removed between 29 and 54 days after insertion. According to the study, retrieval is “difficult and is not always successful.”
The filters are known to tilt, migrate, perforate the vein and/or organs, and fracture, sending fragments of the filter’s legs through the blood vessels and vital organs. The Recovery filter has been linked to at least 27 deaths and hundreds of non-fatal injuries.
The new study advises that the IVC filter was tested according to specific criteria. Some of the criteria was met, such as FDA permission to be sold on the market (via 510(k) approval). However, the most important criteria, such as “the technology’s beneficial effects on health outcomes should outweigh any harmful effects on health outcomes,” that “the technology should improve the net health outcomes as much as or more than established alternatives,” and the device’s improvement on health “must be attainable outside the investigational settings” were not met, according to the study.