[The role of vena cava filters in the prevention of pulmonary embolism and hemodynamic changes in the venous system of the lower limbs]

Abstract

Background: On the basis of recent investigations, pulmonary embolism represents the third cause of death. If only hospitalized population over 65 years of age is considered, this pathology is quite the first cause of mortality. As deep venous thrombosis of the lower limbs represents the main cause of pulmonary embolism (90%), it should be right to suggest interruption of venous flow at caval level. The aim of this prospective report is to evaluate the efficacy of vena cava filter in pulmonary embolism prevention and the hemodynamic variations it can cause in the venous district of lower limbs.

Methods: 137 definitive caval filters were positionated from 1989 to 1996. Average follow-up was 12.6 months. Patients were controlled at 2-7 days, 1 month and than every 6 months.

Results: Filter perviousness was observed with Kaplan and Meyer's curve and it was 94.7%. There was pulmonary embolism in just 2 cases (1.4%). Filter perviousness was not depending on anticoagulant treatment.

Conclusions: In conclusion, this prospective experience underlines that: caval filter is effective in pulmonary embolism prophylaxis; there are not important hemodynamic alterations of inferior vena cava, below filter; anticoagulating treatment does not influence filter perviousness; there are not hemodynamic alterations after slight dislocations of caval filter; finally there is a direct relation between level of deep venous thrombosis and post-phlebitic manifestations.