Long-term optional retrievability of a new inferior vena cava filter in an ovine model

Long-term retrievability of a new optional retrieval inferior vena cava (IVC) filter composed of a modified square stent and a modified Gunther Tulip filter was tested in eight sheep. Eleven filters were placed into the IVC and eight were successfully retrieved 3-5 months after implantation. Incorporation of the filter struts into the IVC wall prevented its retrieval in three sheep at 3, 4, and 5 months after placement.