EXTENDED EVALUATION OF THE TITANIUM GREENFIELD VENA-CAVAL FILTER

Purpose: The purpose of this study was to evaluate the long-term safet y and efficacy of the titanium Greenfield filter-modified hook for pre vention of pulmonary embolism. Methods: We conducted a prospective stu dy in 173 patients from four institutions who underwent clinical exami nation, abdominal radiography, and duplex ultrasound examinations of t he vena cava and lower extremities. If indicated by protocol or clinic al presentation, computed tomography scans, pulmonary angiograms, or v enacavograms 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 c ases. 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 s uspected or confirmed recurrent pulmonary emboli, for an incidence of 3,5% (four of 113), with one death (0.9%). Pour patients had inferior vena cava occlusion at early follow-up and at long-term evaluation, on ly one remained occluded (1%). Insertion site venous thrombosis was se en in only two patients (2%). Conclusion: The titanium Greenfield filt er provides protection comparable to the standard stainless steel Gree nfield filter after 1 pear with a low incidence of recurrent pulmonary embolism (3.5%) and a high caval patency rate (99%).