Prophylactic placement of vena caval filters: a cautionary note.

Greenfield filter placement in patients without deep venous thrombosis has been performed when such patients were felt to be at high risk for asymptomatic deep venous thrombosis and subsequent embolus. In this group placement is termed "truly prophylactic" to differentiate from placement in a patient with documented deep venous thrombosis which has not yet embolized. A retrospective review of Greenfield filter placement at five Dayton, Ohio, community hospitals over three years revealed 59 filters placed in 58 patients. Of these 90% were placed surgically and 10% percutaneously at an average cost of $4,141.00 per surgical procedure. Indications included traditional as well as true prophylaxis. A low morbidity and no mortality related to filter placement was observed. The high efficacy and safety of filter placement seen at large institutions is also found in our community hospital experience despite placement by physicians who perform the procedure infrequently. Although filter placement in patients at a high risk for silent fatal pulmonary emboli may prevent a rare mortality, widespread use of this modality for pulmonary embolus prophylaxis is costly and not without patient risk. We caution against the use of Greenfield filters for pulmonary embolus prophylaxis in patients without deep venous thrombosis until evidence of superior efficacy compared to other forms of prophylaxis can be demonstrated.