Aside from a heart problem, the most common cause of thrombosis is an irremovable Inferior vena cava filter (IVC filter). The amount of IVC filters implanted in U.S. patients is 25 times higher than in Europe, leaving many Americans to deal with serious IVC filter thrombosis and other complications.

Thrombosis occurs when a blood clot forms and travels to an organ, which causes a potentially life-threatening blockage of blood flow. Despite the fact that a third of IVC filter patients will experience thrombosis, doctors haven’t been successfully removing the dangerous devices.

Though 1 in 4 deaths worldwide is caused by thrombosis, symptoms may be hard to recognize. Symptoms of IVC filter thrombosis include:

  • Heavy legs
  • Swelling
  • Cramping
  • Back pain
  • Abdominal pain

“Since IVC filter thrombosis is the main etiology for IVC thrombosis, physicians may want to ensure the absolute need for the filter before its placement,” Dr. Mohamad Alkhouli from University of Rochester Medical Center, New York told Reuters Health by email. “A tracking system should be instituted to follow up with these patients, and the implanted IVC filter should be pulled out as soon as is safe and reasonable.”

Do you have an IVC filter implant? Learn more about the medical device by reading out guide to IVC filters.