The potential beneficial effect of metal surface treatment using electrochemical polishing on stent thrombogenicity and neointimal hyperplasia was evaluated in a rat A-V model and a porcine coronary model. Thrombogenicity of polished stents (n=6) was compared to non-polished stents (n=5) in a rat A-V shunt model using 125I-fibrinogen and 51Cr-labelled platelets. Total clot weight after 30 min was significantly lower in the polished stents (32.1+/-2.8 vs 18.1+/-4.4: p<0.001). Also, 125I-fibrinogen deposition was significantly lower in the polished stents (1.30+/-0.07 vs 0.66+/-0.04: p<0.001). Platelet deposition was, however, not significantly reduced (12.7+/-3.4 vs 9.87+/-1.9, NS). Subsequently, the effect of electrochemical polishing on neointimal hyperplasia was evaluated in a porcine coronary model. Polished (n=10) and non-polished stents (n=10) were randomly implanted in the right coronary artery of healthy pigs. Neointimal hyperplasia was significantly decreased in the polished stents (0.56+/-0.28 vs 0.94+/-0.34 mm2: p<0.01).