The only widely accepted and validated indications for vena cava filter placement in patients with thromboembolism are an absolute contraindication to therapeutic anticoagulation, and failure of anticoagulation when there is acute proximal venous thrombosis. These are discussed in more detail elsewhere. (See "Treatment of acute pulmonary embolism", section on 'IVC filters' and "Treatment of lower extremity deep vein thrombosis".)
Other possible treatment indications, and prophylactic filter placement, are more controversial [1-8]. As result, the use of caval filters varies widely [9-12]. Although vena cava filters can be placed into the superior vena cava (SVC) in select situations, the inferior vena cava (IVC) is the standard location for filter placement. The placement and complications associated with predominantly IVC filters are reviewed here. Other treatments for deep venous thrombosis and acute pulmonary embolism are discussed separately. (See "Low molecular weight heparin for venous thromboembolic disease" and "Treatment of acute pulmonary embolism" and "Fibrinolytic (thrombolytic) therapy in acute pulmonary embolism and lower extremity deep vein thrombosis".)
Knowledge of the normal and variant anatomy of the vena cava is important for successful placement of vena cava filters and prevention of complications.
The major veins of the upper and lower extremity drain into the central veins. In the upper extremity, the subclavian veins arch cephalad behind the medial clavicle and then slope caudally to join the internal jugular veins and form the brachiocephalic (innominate) veins (figure 1). The thyroid veins contribute to the left brachiocephalic vein, and together with the right brachiocephalic vein and azygos vein, these join to form the superior vena cava, which drains into the right atrium.
In the lower extremity, the common femoral veins become the external iliac veins after passing below the inguinal ligament (figure 2). They are joined by the internal iliac veins to form the common iliac veins. The common iliac veins merge at the level of the umbilicus to form the inferior vena cava (IVC) at the L5 level. It continues superiorly to the right of the aorta and receives multiple lumbar tributaries. At the L1 to L2 level, the right and left renal veins join the IVC and this junction divides the vein into the infrarenal and suprarenal portions. Because the inferior vena cava is usually located to the right of the spine, the left common iliac vein is longer with a less vertical path to the IVC.