Canadian medical regulators have issued a new warning regarding serious complications potentially associated with IVC filters, especially those intended for temporary placement. Among other things, the July 26th Health Canada alert urged doctors to carefully weigh risks and benefits before they opt to use these devices in their patients.
IVC filters are small, cage-like implants that are inserted into the inferior vena cava, where they intercept blood clots before they can travel to the heart and lungs. According to Health Canada, the filters have been cited in 121 adverse event reports as of June 6, 2016. Many of these instances involved caval perforation, caval thrombosis, filter fracture and fragment embolization, intracardiac migration, cardiac perforation, cardiac tamponade, and death. The agency reminded physicians that IVC filters are only indicated for use in patients at risk for either acute DVT of the legs or acute pulmonary embolism, and for whom standard anticoagulant therapy is contraindicated.
Health Canada also noted that many of the reported injuries were associated with long-term (greater than 30 days) filter implantation. The alert pointed out that retrievable IVC filters are intended for short-term placement and, when possible, should be removed when anticoagulation therapy can be started or if a patient’s risk of pulmonary embolism subsides. The agency recommended that recipients of these devices be scheduled for a retrieval assessment at the time of placement. If the subsequent assessment indicates that retrieval is appropriate, the patient should be referred for the removal procedure when feasible.
Health Canada continues to monitor the safety and effectiveness of IVC filters, and has directed device manufacturers to established post-market evaluation protocols to aid in this effort. The agency is also encouraging physicians to participate in clinical studies or develop plans for long-term follow-up of IVC filter patients so that data can be collected on the safety and effectiveness within specific patient populations.
In 2010, the U.S. Food & Drug Administration disclosed that its adverse event database had received more than 900 reports of IVC filter complications linked to retrievable devices. Four years later, the agency issued a second advisory that urged doctors to remove temporary blood clot filters within 29 to 54 days of their implantation in order to reduce the risk of patient harm. Since then, more than 1,300 IVC filter lawsuits have been filed in U.S. courts on behalf individuals who allegedly suffered serious complications related to retrievable devices manufactured by C.R. Bard, Inc. and Cook Medical, Inc.