Extended evaluation of the titanium Greenfield vena caval filter.

PURPOSE: The purpose of this study was to evaluate the long-term safety and efficacy of the titanium Greenfield filter-modified hook for prevention of pulmonary embolism.

METHODS

We conducted a prospective study in 173 patients from four institutions who underwent clinical examination, abdominal radiography, and duplex ultrasound examinations of the vena cava and lower extremities. If indicated by protocol or clinical presentation, computed tomography scans, pulmonary angiograms, or venacavograms were obtained.

RESULTS

The most common procedural event was filter limb asymmetry (10%), which had no clinical significance. A variety of other minor procedural events occurred in another 10% of cases. Early follow-up (< 6 months) was completed in 149 patients, and long-term evaluation was completed in 113 (> 12 months). Deaths in 24 patients were from nonembolic causes in all but one. There were four suspected or confirmed recurrent pulmonary emboli, for an incidence of 3.5% (four of 113), with one death (0.9%). Four patients had inferior vena cava occlusion at early follow-up and at long-term evaluation, only one remained occluded (1%). Insertion site venous thrombosis was seen in only two patients (2%).

CONCLUSION

The titanium Greenfield filter provides protection comparable to the standard stainless steel Greenfield filter after 1 year with a low incidence of recurrent pulmonary embolism (3.5%) and a high caval patency rate (99%).