After an extensive analysis of several years of patient data, a group of surgeons from the Albert Einstein College of Medicine in New York City have determined that patients with traumatic spinal cord injury (SCI) who are given an inferior vena cava (IVC) filter are actually at higher risk for deep vein thromboembolism (DVT) than those who were simply given anticoagulant medication. This supports an earlier retrospective chart review that came to a similar conclusion several years ago.

Emboli, or blood clots that travel to the heart and/or lungs, is a common risk for SCI patients. Normally, such patients are either given an anticoagulant drug, such as heparin, or made to wear compression stockings in order to prevent thrombosis. However, due to various factors in which the body fails to break down clots in the blood stream, SCI victims remain at risk for DVT for much longer than other patients. According to a study published in the journal Neurology in 1994, such patients were at risk for embolism for an average of 78 days following surgery, accounting for over 30% of all embolism emergency room admissions.

The practice of inserting IVC filters in SCI patients who are either partially or completely paralyzed dates back to 1991. However, more recent studies have indicated that the use of IVC filters may be completely ineffective in preventing thrombosis. For example, one study published in the Journal of Trauma in 2002 found that the rate of DVT and pulmonary embolism for SCI patients with IVC filters was similar to that of trauma patients in general when other preventive measures were employed. Another study, published in the same journal in 2009, concluded that IVC filters actually put SCI patients at greater risk for DVT. In 2011, a data review published in Vascular Medicine concluded there was “little evidence to support IVC filter insertion in any population”.

Despite these findings, the use of IVC filters to prevent DVT and PE in SCI patients has remained a common practice. Physicians at Albert Einstein and the Jacobi Medical Center wanted to find out if there was any benefit at all to the use of IVC filters in SCI patients. According to Dr. Ravi Kapadia, the filters actually cause more problems than they solve. He said, “The filter in and of itself is thrombogenic, which can explain the higher rate of pulmonary emboli in the filter group.” He also pointed out that:

…it is not uncommon to see small clots on top of the filter when we remove them. These small clots can manifest as subclinical PE, so the rate of pulmonary embolism is probably much higher. We just happen to only know about those that manifest clinically.

In other words, the IVC filters themselves are actually causing embolism – and since symptoms are not always readily apparent, chances are that the condition is far more common than previously believed.

This news comes on top of several years of reports indicating that IVC filters are both dangerous and useless – yet, despite the evidence as well as a safety alert issued by the FDA in 2010, these devices are used in the U.S. at a 2500% higher rate than elsewhere in the world.

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K.J. McElrath is a former history and social studies teacher who has long maintained a keen interest in legal and social issues. In addition to writing for The Ring of Fire, he is the author of two published novels: Tamanous Cooley, a darkly comic environmental twist on Dante's Inferno, and The Missionary's Wife, a story of the conflict between human nature and fundamentalist religious dogma. When not engaged in journalistic or literary pursuits, K.J. works as an entertainer and film composer.