Twenty-seven Gianturco-type self-expandable stainless steel intravascular stents were placed into the infrarenal abdominal aortas(n=17) and inferior venae cavae(n=10) in 14 mongrel dogs. In 8 aortas, stents were delivered after balloon catheter-induced denudation of the intima, and in 4 out of the 8 aortas, the stents were also placed into the normal sites to compare the neointimal thickness of the normal and denuded sites. Angiography, light microscopic, and scanning electron microscopic examinations were performed after 1 week. Nearly complete transparent neointimal covering was found in the aortas and caval veins after 2 weeks. There was no significant difference in intimal thickness between the denuded and normal aortas after 2 weeks (p=0.51) and 3 weeks(p=0.56). In 4 dogs with caval vein stents, there was evidence of hemorrhagic infarction in the lungs. The thrombosis rate of 12 stents with a stent-artery ratio(SAR) of 1.5 or higher was 41%, while there was no thrombus on the 4 stents with SAR 1.2 or lower, except for 1 specimen after 1 week. It is suggested that stents with SAR 1.2 or lower are more suibtable. The high thrombosis rate of the inferior vanae cavae may be related with slow blood flow.