The Kimray-Greenfield vena cava filter: a case of unusual misplacement

Transvenous Interruption of the Inferior Vena Cava. New Model of Vena Cava Filter. Preliminary Results in 143 Cases

A new device for transvenous interruption of the inferior vena cava is described. Based upon the Greenfield filter, upward- and downward-facing hooks prevent movement of the filter within the vein. Results of the use of the device in 143 patients after 3 months are presented and compared to other filters.

Complications encountered with the use of the Greenfield filter

The Greenfield filter can be used with a low complication rate provided one adheres to certain principles. First, preoperative venography to define the inferior vena caval anatomy will help avoid difficulties associated with anatomic variations. At the time the study is carried out, it would be extremely useful if the radiologist places a radiopaque marker at the level of the renal veins. This will ensure that filters will be placed in the infrarenal position when appropriate, thus preventing occasional inadvertent discharge, particularly into the right renal vein. Second, use of a guide wire greatly facilitates passage of the introducer and accurate intracaval positioning. Third, intraoperative technical errors must be recognized and promptly corrected. Finally, meticulous postoperative follow-up is essential, and recurrent embolism or any change in filter position requires repeat roentgenography of the vena cava to guide appropriate corrective treatment.

Misplacement of a vena cava filter in the retroperitoneum

An inferior vena cava filter was misplaced into the pericaval retroperitoneum. This was probably secondary to placement into and avulsion of the right spermatic vein. The filter delivery system was modified, and such misplacement should now be impossible.