Caval incorporation of the LGM Vena Tech filter: An experimental study

PURPOSE: To analyze LGM Vena Tech filter incorporation and the rapidity of the process. MATERIALS AND METHODS: A filter was inserted into the infrarenal inferior vena cava (IVC) Of 15 ewes assigned to one of three groups depending on the length of follow-up (2, 4, or 8 weeks), Radiologic data concerning IVC diameter and filter patency, stability, and incorporation were obtained before and after insertion and before euthanasia. Histopathologic analysis concerned wall thickness and smooth muscle cell area (SMCA) at three levels of the filter and at one point outside the filter. RESULTS:. All filters remained patent during follow-up, Incorporation of struts was dependent on time (P = .006), level of the filter (P = .0001), and strut surface (P < .0001), Neointimal thickness increased during follow-up (P = .0002), being more marked in the midportion of the filter (P = .0037), Adventitial thinning was observed (P = .0001), corresponding to a significant decrease in SMCA (P < .0001) above the struts as a function of the length of the follow-up period (P = .0021). CONCLUSIONS: The LGM Vena Tech filter was well tolerated and is suitable for incorporation into the IVC wall of normal animals without risk of any deleterious reactions due to biological incompatibility.