A healthy, 41-year-old woman came to the emergency room at the Hospital of the University of Pennsylvania, complaining of chest pain. She said that for the last day she had pain in the left side of her chest that caused her to feel short of breath. The pain became much worse when she took deep breaths.
"I had a deep venous thrombosis [DVT] — a blood clot — in my leg years ago, they gave me an IVC filter because I couldn't take blood thinners," she said.
Instead of receiving blood thinning medications for her clot, she received a filter (also called a "clot catcher") in the inferior vena cava – the large vein that delivers blood from the legs and belly to the heart. The filter is shaped like a tripod with a net on top. It works like a colander – blood goes through, clot does not.
Her heart and lungs appeared normal. Her pulse was strong and her legs did not appear swollen or painful, which may be concerning signs of a blood clot.
We checked her vital signs: they were normal except for an elevated heart rate.
Since chest pain can pertain to a number of vital organs including the heart, lungs, and aorta, we considered several life-threatening possibilities including heart attack, inflammation of the heart, pneumothorax and pneumonia. Her blood tests, chest x-ray and EKG were all normal.
But something just didn't fit.
Her symptoms seemed to suggest a possible blood clot but with an IVC filter in place, the likelihood of her having a dangerous pulmonary embolus, or blockage, was quite low. We rechecked her vital signs — including her heart rate, which remained elevated — and ordered a CT angiogram study of the pulmonary arteries, the gold-standard test for diagnosing a pulmonary embolism.
What we discovered next was entirely unexpected.
The CT angiogram on this 41-year-old woman revealed a scary finding. Rather than a blood clot, we found that one of the struts of her IVC filter had broken off and traveled to her lungs. Ironically, the medical device that was supposed to prevent a pulmonary embolus actually became a pulmonary embolus when a component traveled ("embolized") to her lungs.
It turns out that a small number of case reports have demonstrated IVC filter embolization. The literature shows strut malfunctions including reports of an IVC filter strut actually puncturing straight through the heart. Although these filters are generally safe, these reports demonstrate that IVC filters can cause complications and ought to be removed as early, and as safely, as possible.
Chest pain is one of the most common symptoms for which people present to the emergency department, and it can be especially hard for a patient to decide whether the chest pain warrants a medical evaluation. Although this case was rare, it is a prime example of why we must always look for dangerous "red flag" signs and symptoms.
Signs and symptoms that may indicate a serious cause of chest pain:
Our patient was eventually admitted to the hospital so that an interventional radiologist could remove the strut found stuck in the blood vessels of her lung. She was eventually discharged in perfect health after several days of recovery.