PURPOSE: To evaluate the behavior and endovascular response of a new nitinol permanent vena cava filter, the TrapEase. METHODS: Percutaneous implantation of the filter was performed in six goats, with inferior vena cava (IVC) diameter close to that of man. Radiologic data concerning the IVC, filter diameter, patency and stability were collected. At 2, 4, 20 and 26 weeks post-implantation, histopathologic analysis of the IVC wall was performed at the site of filter distension, and distal and proximal to the filter. RESULTS: All filters remained patent. There was no migration and no signs of biological incompatibility. Signs of neointimalization were seen at 2 weeks, with well-developed neointima at 4 weeks. No acute vessel wall perforation was detected by cavography at implantation. During follow-up histologic analysis at 26 weeks, perforation of some of the small fixation barbs was seen, causing minimal damage to the vessel wall and adjacent organ tissue without impairing organ function. These events were well tolerated, probably due to the gradual nature of the penetration of fixation barbs allowing reactive fibrous tissue development. At 26 weeks the parallel filter struts were well covered with neointima and did not perforate the vessel wall. There were no complications associated with the filter implantation. CONCLUSIONS: The TrapEase vena cava filter was well tolerated and is suitable for incorporation into the IVC wall of healthy animals without any apparent deleterious reaction due to biological incompatibility.
PURPOSE: To evaluate the behavior and endovascular response of a new nitinol permanent vena cava filter, the TrapEase. METHODS: Percutaneous implantation of the filter was performed in six goats, with inferior vena cava (IVC) diameter close to that of man. Radiologic data concerning the IVC, filter diameter, patency and stability were collected. At 2, 4, 20 and 26 weeks post-implantation, histopathologic analysis of the IVC wall was performed at the site of filter distension, and distal and proximal to the filter. RESULTS: All filters remained patent. There was no migration and no signs of biological incompatibility. Signs of neointimalization were seen at 2 weeks, with well-developed neointima at 4 weeks. No acute vessel wall perforation was detected by cavography at implantation. During follow-up histologic analysis at 26 weeks, perforation of some of the small fixation barbs was seen, causing minimal damage to the vessel wall and adjacent organ tissue without impairing organ function. These events were well tolerated, probably due to the gradual nature of the penetration of fixation barbs allowing reactive fibrous tissue development. At 26 weeks the parallel filter struts were well covered with neointima and did not perforate the vessel wall. There were no complications associated with the filter implantation. CONCLUSIONS: The TrapEase vena cava filter was well tolerated and is suitable for incorporation into the IVC wall of healthy animals without any apparent deleterious reaction due to biological incompatibility.