It is not mandatory to remove the filters put in the leg thrombus, it is decided according to the type of thrombus filters placed, generally there are two kinds of temporary thrombus filters and permanent thrombus filters. 1. Permanent thrombus filters: If the patient is placed in a permanent thrombus filters, can not be removed, but the thrombus filters on the human body belongs to a foreign body, may cause recurrence of thrombus or thrombus dislodgement and so on, the need for long-term anticoagulant medication, such as aspirin, warfarin, etc., if the patient uses anticoagulant drugs for too long, it will increase the body’s tendency to hemorrhage, resulting in the body easy to bleed in various places. 2. Temporary thrombus filters: If the patient is placed on a temporary thrombus filter, the filter is usually removed after 2 weeks of implantation through intervention. If the patient’s condition is not yet stabilized, the filter can be extended to 1 month after placement and then removed, which usually does not have any adverse effects on the patient. Patients are advised to go to the hospital and choose the appropriate option after detailed introduction by the doctor.