PURPOSE: To evaluate the patency of the Hanaro self-expanding stainless steel stent in the common carotidartery of the pig. MATERIALS AND METHODS: Sixteen stents(6mm in diameter/3.5mm in length) were inserted in one orboth common carotid arteries of nine pigs. Carotid angiography was performed before and after stent insertion, and at the end of the follow-up period(which ranged from 4 to 13 weeks), to evaluate stent patency and change of stent location. Histopathologic study was carried out to assess the endothelial proliferation. RESULTS: Of nine pigs with 16 successfully-inserted stents, follow-up angiography was obtained in seven pigs with 13 stents. The stents inserted were patent in 12 cases and occluded in one. Stenosis was noted in nine of the 12 stents. In three stents, there was angiographic evidence of recanalization such as non-filling or collateral filling of the rete. In no case was there any change of stent location. Endothelial proliferation was more severe in two of four occluded stents(mean thickness : 0.43mm) than in the other 11 stents(mean thickness : 0.08mm). CONCLUSION: Because the Hanaro stent was successfully inserted in porcine carotid arteries and showed a rather good patency(92%), the stent can be used in the small arteries. However, before it is used clinically, futher study and development appear to be necessary.