Inferior vena cava filters trap dislodged clot and decrease recurrent pulmo
nary embolism. The main indications am pulmonary embolism or extensive deep
vein thrombosis when anticoagulants am contraindicated, and recurrent pulm
onary embolism despite adequate anticoagulation. Newer filters trap clinica
lly significant emboli while maintaining patency, making them safe and effe
ctive.