SYMPTOMATIC INFERIOR VENA-CAVA FILTER THROMBOSIS - CLINICAL-STUDY OF 30 CONSECUTIVE CASES

Inferior vena cava (IVC) filter thrombosis has not been described as a clinical entity. Thirty patients with IVC percutaneous filter thrombo sis were assessed by cavography, computed tomographic (CT) scan and/or duplex ultrasonography.All patients had proximal venous thrombosis wh en the filter was placed, and the indication for filter placement was a contraindication to anticoagulant therapy in eight patients (27%). F ilter thrombosis occurred within 6 months following fitter placement i n 15 patients (early filter thrombosis group), Among these patients, 1 0 were not treated with oral anticoagulant, and none of the other five received adjusted anticoagulation. No patients with late filter throm bosis received anticoagulant at the time of the diagnosis, Early filte r thrombosis was mainly associated with LGM filters (12 of the 15 case s), Occlusion was revealed by recurrent venous thrombosis in 18 cases, A thrombus above the filter and pulmonary embolism was found in 10 pa tients (33%). Thrombolytic therapy failed in 5 out of 7 cases, and all but two patients were treated with anticoagulant therapy. In conclusi on, early filter thrombosis appears to be due to intracaval extension of deep vein thrombosis, and this emphasizes the need for appropriate anticoagulation. In the case of temporary contraindication to anticoag ulation at the time of the filter placement, anticoagulant should be r eassessed later.