Use of a new removable vena cava filter in order to prevent pulmonary embolism in patients submitted to thrombolysis

The authors present a removable vena cava filter that may be introduced percutaneously, is atraumatic to the venous wall, and permits the simultaneous use of thrombolytic therapy. Sixty-five patients were studied: 42 cases of pulmonary embolism with threatening venous thrombosis; 23 cases of phlebitis associated with an ilio-caval thrombus without pulmonary embolism. The filter was introduced 38 times femorally and 27 times by a jugular approach. In 16 cases (24.6%) clots broke loose, were effectively caught by the filter, and were progressively dissolved during thrombolytic therapy. The filter remained in place on average 4.5 +/- 1.2 days. The filter was removed in all cases without provoking the recurrence of pulmonary embolism. Two deaths, not related to pulmonary embolism, occurred during hospitalization. Phlebography, performed in all cases before and after treatment, showed a significant decrease of the phlebographic score (10.88 +/- 0.82 vs 6.77 +/- 0.86, P less than 0.001). The same was observed in 40 patients who underwent a pulmonary angiography before and after treatment (Miller index = 17.04 +/- 0.73 vs 5.49 +/- 0.87, P less than 0.0001). After removal of the filter, no sign of pulmonary embolism was detected on lung scan in the 23 patients with ilio-caval thrombus alone. More than 5 g (100 ml)-1 of haemoglobin was lost by 15.38% of patients. All patients were followed-up for a mean of 7.12 +/- 1.3 months; in no case was there any clinical recurrence of pulmonary embolism. Thus this device allows an effective temporary filtering of the vena cava.