The consequences of a blood clot going down the filter without retrieval are not serious in the vast majority of patients. If a thrombus goes down a retrievable filter but is not retrieved, the retrievable filter will form a permanent filter, which generally does not have a significant impact on the body. Although there is a possibility of recurrence of the thrombus or dislodgement of the thrombus, causing a thrombus inside the filter and blocking the inferior vena cava, etc., which affects the venous blood return to the lower extremities. In this case, the thrombus inside the screen can be removed mechanically, or a thrombolytic catheter can be placed inside the screen for thrombolysis, which can eliminate the thrombus inside the screen, open the inferior vena cava, and reduce the patient’s symptoms. Of course, it is possible for the screen to displace or break, so the choice of treatment will depend on the patient’s specific situation.