Retrieval of the Greenfield vena caval filter.

A retrieval device has been developed that allows removal of misplaced Greenfield vena caval filters. The technique was evaluated in 15 dogs in which filters were placed in the vena cava, iliac vein, or right atrium. Retrieval was possible in seven of nine dogs up to 7 days after insertion. After 7 days, retrieval was not possible because of fixation of the device. Retrieval was not possible in dogs with a jugular vein too small to accept the retrieval unit. The case of one patient in whom the filter was dislodged at the tricuspid valve is reported herein. This experience confirms that retrieval can be accomplished without significant risk.