Can patients with an IVC filter still get PE?
Yes. There are several ways for patients with a filter to get PE. A patient may have had an anatomic variant that was not recognized during filter placement that permitted a clot to bypass the filter. Even in the absence of such variants, a filter would not protect a patient from PE originating in every part of the body. A filter would not offer protection from a clot originating in the upper extremities or right atrium. Similarly, a clot from an ovarian vein that embolizes to the renal vein and then centrally would not be stopped by an infrarenal filter. Small clots may pass through a filter, and large clots may propagate through a filter as pieces break off and embolize centrally. Overall, the rate of recurrent PE in patients with caval filters ranges from 3% to 5%. These rates are based on clinical findings and imaging studies performed in patients to detect symptomatic PE. The rates of asymptomatic PE after IVC filter placement are largely unknown.