Cephalic migration of the bird's nest inferior vena caval filter: report of two cases.

The Bird's Nest inferior vena caval filter (Cook, Bloomington, Ind) has been approved for clinical use since 1989. The authors report two cases of cephalic migration of the filter. Both cases of migration occurred in association with a massive thromboembolism after placement of the filter. It appears that a massive thromboembolism can cause this filter to migrate cephalad. The authors suggest that there is potential for nonsurgical management of the migrated filter.