For inferior vena cava (IVC) filters, the risk of injury increases with a longer dwelling time, according to tctMD.com.
Despite a safety communication from the FDA in 2010, the device is still being left in place longer than recommended. Due to the fragile nature of IVC filters, the devices easily break apart or migrate, and have been known to do so even within the “safe” time limit. According to the safety communication, dated Aug. 9, 2010, the FDA recommends that the filter stay in place no longer than 29 to 54 days after implantation.
“The message is that if you have a patient who’s had a filter in for 7 months or longer, really consider that they may need more than a standard technique and consider referral for advanced retrieval,” Kush R. Desai, MD (Northwestern University Feinberg School of Medicine, Chicago, IL) told TCTMD in an interview. Desai is the lead author of the study that claims that a dwell time of more than seven months leads to a device failure rate as high as 40 percent.
“The necessity of advanced techniques to maintain technical success of retrieval increases with dwell time,” the study concluded. “Patients with retrievable inferior vena cava filters in place beyond 7 months may benefit from referral to centers with expertise in advanced filter retrieval.”
A retrievable IVC filter is a metallic device closely resembling a spider with a hook at its apex to snare for removal. They are surgically inserted into the inferior vena cava, the largest vein in the body, and are designed to prevent pulmonary embolism by catching blood clots before they reach the heart or lungs.