Health Canada has issued a safety alert regarding the use of inferior vena cava (IVC) filters, which are used to stop blood clots from reaching the heart or lungs. The regulators warned that patients receiving IVC filters have reported serious complications, including: caval perforation, caval thrombosis, filter fracture and fragment embolization, intracardiac migration, cardiac perforation, cardiac tamponade, and death. The alert stated that many of these complications occurred when the filter was left for more than 30 days, or long-term filter implantation.
The agency advised healthcare professionals to consider the use of IVC filters carefully. Health Canada says the devices are still indicated for patients with acute proximal deep vein thrombosis (DVT) and acute pulmonary embolism who cannot use anticoagulant drugs. DVT is when a blood clot forms in one of the deep veins of the body, usually the legs. If a piece of the clot breaks off it can become lodged in the lungs, leading to the life-threatening condition known as pulmonary embolism.
IVC filters are either retrievable, meaning they are meant to be removed, or permanent. Health Canada said that retrievable filters should be removed once patients are able to take anticoagulants or if pulmonary embolism is no longer a risk; they are intended for short-term placement. The regulator advised hospitals to identify patients with retrievable IVC filters and develop plans to assess removal.
According to the alert, 121 incidents of serious IVC filter complications have been reported to Health Canada as of June 6, 2016. “Serious complications such as caval perforation, caval thrombosis, filter fracture and fragment embolization, intracardiac migration, cardiac perforation, cardiac tamponade, and death have been reported in patients who have been implanted with IVC filters. Many of these complications occurred with long-term (greater than 30 days) filter implantation.” the notification said. Health Canada also noted that these IVC filter issues have been reported internationally.
Health Canada listed several IVC filter manufacturers affected by the notice, including: A.L.N., Bard Peripheral Vascular, B. Braun Medical, Cordis Cashel, REX Medical LP and William Cook, Europe APS and Cook Inc.
Consumers with retrievable IVC filters are encouraged to talk to their physicians about when the filter should be removed.
Health Canada released the notice after reviewing clinical evidence regarding the safety and efficacy of IVC filters. The agency noted that there have been many studies assessing IVC filters, but only two randomized controlled trials (RCTs) have been conducted. RCTs randomize participants to receive either an intervention or a control (which may be a placebo or no treatment at all). This type of study is one of the most powerful tools in clinical research. The RCTs compared patients with Venous Thrombo-Embolism (VTE) who received either anticoagulation therapy with IVC filter placement or anticoagulation therapy alone. Health Canada said the trials failed to show benefits with IVC filter use in patients who are able to take anticoagulants. “Results from these two RCTs do not support the use of IVC filters in patients who can be treated with anticoagulation. Reductions in VTE and mortality have not been demonstrated.” the alert said.