Deployment problems with the titanium Greenfield filter

The authors retrospectively reviewed their initial experience with deployment of the modified hook titanium Greenfield filter.

Twenty-three patients underwent filter placements over a 1-year period. Radiographs were obtained immediately after placement to confirm filter position in all cases. Follow-up images were available in 15 patients (65%).

Twenty-four filters were placed in 23 patients. Tilting of the filter (> 15 degrees) was evaluated in 22 placements without complications and was present in five (23%). In 17 of 24 placements (71%), distribution of filter legs was poor, with wide gaps between clustered legs. Manipulation of the filter legs with an angiographic catheter resulted in improved distribution in three of six attempts but also resulted in a caudal displacement, which necessitated placement of a second filter. At follow-up (range, 4-16 months; mean, 9 months), three cases of asymptomatic inferior vena caval thrombosis and one recurrent pulmonary embolism were discovered.

No untoward event resulting from filter placement was demonstrated. Further study and review of the deployment mechanism may be necessary.