After several years of growing popularity, use of IVC filters started falling in 2010 – shortly after the FDA issued a safety alert about the long-term use of these devices. According to two studies presented at a recent meeting of the Society of Interventional Radiology, this decrease can be attributed to the FDA warning.
The origin of the inferior vena cava (IVC) filter can be traced back to the 1960s, when Dr. Kazi Mobin-Uddin invented a filter that resembled an umbrella. However, there were problems with that device: not only was there the potential for migration (movement), it could also become obstructed.
The modern IVC filter came along in 1981, when a surgeon named Lazar J. Greenfield developed what was then known as the “Greenfield Filter.” It was similar in appearance to today's IVC filters, and was advertised as the “first percutaneous filter that did not necessitate venotomy” – meaning it could be inserted without the necessity of making an incision.
In the years that followed, the number of indications increased until a 1998 study showed no real benefit to patients at risk for deep vein thrombosis who could otherwise be treated with anticoagulants. Furthermore, unless they were removed within the first three weeks, retrieval was difficult.
Nonetheless, the use of IVC filters kept increasing throughout the 1990s and first decade of the 21st Century. This trend continued, even though rates of pulmonary embolism remained virtually unchanged. After the FDA issued its advisory, however, the number of IVC filters began to drop by more than 7% annually.
One interesting aspect to this decline is that it has not been consistent across the country. According to Dr. Ketan Petal of Rush University Medical Center in Chicago, most of the decrease has been in the Northeastern region of the U.S., which he describes as having “a more litigious medicolegal environment.”
Western states also showed a significant decline. However, surgeons in the South continue to implant these devices regularly. Dr. Petal had no explanation for these findings, but it may have to do with tort reform efforts in some of those states, which have capped awards and made it more difficult for medical malpractice plaintiffs.
At the same time that use of IVC filters has declined, health care facilities specializing in the retrieval and removal of IVC filters has increased significantly. Although IVC filters manufactured after FDA approval in 2004 were designed to be removable, the procedure is difficult and dangerous.