The primary purpose of this study is to compare the Celect and Denali filters in terms of complicated filter retrieval and indwelling complications after a 2-month indwelling time.

With anticoagulation being the standard treatment for deep venous thrombosis and pulmonary embolism, inferior vena cava filter placement plays an important role in patients who are amenable to anticoagulant therapy. Currently, many different types of retrievable filters are being used in clinical practice and the choice of the filters depends on operators' preference and institutional availability. Each filter has different designs to maximize retrievability and minimize indwelling complications. Up until now, the prior studies on the filter retrievability and indwelling complications have been retrospective in nature and had relatively long dwell times. Comparative data regarding the retrievability of the inferior vena cava filters may help to choose filter selection. Therefore, the aim of this trial is to compare two commonly used inferior vena cava filters (Denali and Celet filters)

Inclusion Criteria:

• 1. Patients who develop deep venous thrombosis and/or pulmonary embolism but are good candidates for anticoagulant therapy
• 2. Inferior vena cava filtration before mechanical thrombectomy for deep venous thrombosis
• 3. Prophylactic filter placement because of trauma or major surgery

Exclusion Criteria:

• 1. Sepsis
• 2. Those who need permanent filter placement
• 3. Congenital anatomical anomaly (IVC duplication, interrupted IVC)
• 4. patients who need filter placement in the suprarenal inferior vena cava

Participants are blinded to the filter type.