An experimental study of intravascular stent in abdominal aorta of atherosclerotic miniature pigs.

To study the effects of nitinol alloy stent in the treatment of atherosclerotic arterial stenosis, eight miniature pigs were subject to abdominal aortic balloon denudation and high-fatty food. Then 8 nitinol alloy stents were implanted into each abdominal aortas of pigs. The pigs were equally divided into two groups. One group was given captopril (3 mg/kg/d). All animals were sacrified for pathological examination 6 to 10 months after stent implantation. The degree of arterial intima proliferation in the areas of stent implantation not significantly different from that of areas of balloon denudation alone; the atherosclerotic lesions were found at the arterial surface of stent implantation sites. The intima layer was rich in smooth muscle cells, with atherosclerotic plaque formed around the stent wire. On the other hand, significant decrease in arterial intima proliferation was found in group II with no atherosclerotic plaque. The arterial stenosis resulting from atherosclerotic lesion could not be prevented by implantation of intravascular stent, and on the contrary, the mechanical stress of stent wire might worsen the atherosclerosis. Captopril might impede the development of atherosclerotic stenosis after stent implantation.