At first, IVC (inferior vena cava) filters seemed to be a great idea. Anticoagulant medications can be tricky, causing an elevated risk of serious hemorrhaging, and some patients cannot handle them at all. Placing a small metal cage into the primary artery leading to the heart and lungs in order to trap clots and prevent them from reaching it appeared to be the ideal solution. So, why is it that this particular cure has proven to be worse than the disease?
The IVC filter, a small metal cage that is implanted in the large artery leading from the lower body to the heart itself, has been used for patients who have undergone hip and knee surgery and are at risk for a pulmonary embolism or a blood clot traveling to the lung – either of which can have fatal consequences. However, what has happened in many cases is that the filter fractures, sending small, sharp metal shards through the patient's circulatory system, or falls out of position altogether. Either way, this can cause severe, painful and life-threatening injuries. When the artery is punctured, it can cause secondary injuries to other organs. The metal shards can even reach the heart itself, causing arrhythmia (irregular heartbeat), perforating the walls of the heart chamber. It can also result in a condition known as cardiac tamponade, in which fluid such as pus or blood leaks into the pericardium (the tissue lining surrounding the heart muscle), causing pressure and interfering with heartbeat.
Although the IVC filter seems to work well for the first few months following implantation, the longer it remains inside the patient's body, the greater the chances that the device will fail. Furthermore, the longer it stays in the IVC, the more difficult it is to remove.
Researchers from the radiology department of Scott & White Memorial Hospital in Dallas, Texas have determined that over time the metal of the IVC filter causes a reaction with the tissue making up the arterial walls. Eventually, the filter actually grows into the arterial lining. The other contributing factor is the motion of the artery itself as the heart pumps blood and the patient engages in everyday movements. This motion causes the artery to flatten and expand, placing stress on the device and causing metal fatigue (think of bending a metal paper clip back and forth until it breaks).
Although the Food and Drug Administration issued warnings about IVC failure as long ago as 2010, these warnings have generally been ignored by manufacturers such as C.R. Bard, Cook Medical and Cordis. These companies neglected to inform physicians about the risks of leaving IVC filters implanted in the patient for an extended period. Currently, there are more than 1500 lawsuits that have been filed against these manufacturers. It is yet one more example of corporate malfeasance in which company executives place profits above human health and well-being, willing to risk paying out a few million dollars in settlements in order to preserve the bottom line.