Bioavailability of EVA-Coated Metallic Stents Implanted in the Rabbit Iliac Artery

ABSTRACT

BACKGROUND AND OBJECTIVES: Coronary artery stenting actually shows a high efficacy in the treatment of coronary heart disease, but has the major limitation of restenosis. The ethylene-vinyl acetate copolymer (EVA), a biocompatible nondegradable copolymer, has been employed as a rate-controlling membrane in several drug delivery systems. Herein, the feasibility of an EVA-coated coronary stent was evaluated as a possible route for localized drug delivery. MATERIALS AND METHODS: A total of 15 rabbits were employed in this study. An uncoated stent was implanted into the non-diseased iliac artery in six rabbits, and an EVA-coated stent into a further nine. On the 30th day following the stent implantations, stented segments of the iliac arteries were removed for histological processing and morphometric analysis. RESULTS: The mean neointimal area of the uncoated and coated groups were 1.009 and 1.011 mm2 (p=0.56), respectively. No inflammatory cells were found in coated group. There were no apparent differences between the two groups. CONCLUSION: The results from this study have demonstrated that an EVA-coated coronary stent might be an appropriate method for the controlled-release of a drug.