Distal migration and deformation of the Greenfield vena cava filter.

We have presented two patients in whom distal migration of the Greenfield vena cava filter has resulted in complications. In one patient there was marked deformation of the vena cava filter struts for an unknown reason resulting in perforation of the vena cava filter and the small bowel. In a second patient the distal migration resulted in poor alignment of the filter and recurrent pulmonary emboli. We feel that the Greenfield filter represents an excellent choice for caval interruption but that we would like to draw attention to the complication of distal migration. In addition, we would like to point out deformation of the struts of the Greenfield filter for which we have no explanation and which, to our knowledge, has not been reported previously.