OBJECTIVE To verify the penetration of struts and hooks of two inferior vena cava (IVC) filters (Günther tulip retrievable filter [GTF] and Celect filter) through the vena cava wall and to assess local or systemic complications resulting from this penetration. METHODS Eight IVC filters were placed in the IVC of four ewes for 30 days (1 GTF and 1 Celect filter in each ewe). Angiographic and laparoscopic examinations of the animals were performed to demonstrate the penetration through the vena cava wall, and the filters were removed under laparoscopic control. Specimens were extracted for anatomicopathological and histologic examination. RESULTS Two-projection cavography showed a filter leg seemingly out of the vena cava in 19 of 32 legs (59.3%). Laparoscopy showed 7 real penetrating legs (5 Celect filters and 2 GTFs) out of the 14 legs that could be identified by laparoscopy owing to technique limitations. Neither laparoscopy nor necropsy showed any sign of wall hemorrhage or other injuries. Histologic examination showed intimal remodeling and slight thickening of adventitial tissue around filter legs. CONCLUSIONS GTFs and Celect filters can produce a real penetration 1 month after implantation. This penetration did not lead to any complications in the IVC or surrounding tissues and did not compromise the subject's health in any of the studied cases.