Subcutaneously tethered temporary filter: Pathologic effects in swine

PURPOSE: To evaluate the histopathologic effects of the Tempofilter, a temporary caval filter, on the caval wall and determine the feasibility of deployment and removal of the device in swine. MATERIALS AND METHODS: Filters were placed in the infrarenal inferior vena cava of 11 swine, The tethering catheter was sutured in a subcutaneous pocket near the puncture site, The original tethering catheter used in humans and a stiffer catheter designed to prevent migration in swine were evaluated, Postplacement, mid-study, and preexplant vena cavography procedures were performed, Four swine underwent in situ dissection at 3-10 weeks, Filters were removed from seven animals just before they were killed at 1-6 weeks. RESULTS: All filters were successfully placed, Al seven filters were successfully removed at up to 6 weeks after placement, Cephalic migration of more than 1 cm was observed in 10 of 11 swine (100% of original catheters, 83% of stiff catheters), Other complications were more common with stiffer tethering catheters, including caval stenosis in 40% of original catheters and 100% of stiff catheters, filter cone thrombus in 0% and 67%, tethering catheter thrombus in 20% and 83%, pulmonary embolism in 0% and 50%, and death in 0% and 17%, respectively, There was mild vessel wall damage in the vena cava. CONCLUSION: Placement of the Tempofilter and removal at up to 6 weeks after placement is feasible.