Evaluation of self-expandable, FK506-coated, covered stents in canine animal model

This study aimed to evaluate whether drug coating of the recently developed covered SENDAI stents—self‐expandable stents covered with segmented polyurethane (SPU) films—reduces neointimal thickening in animal model. FK506, which is one of the most effective immunosuppressants, was used. Bare stents; non‐coated, covered stents; and FK506‐coated, covered stents were placed bilaterally in the external iliac arteries of beagle dogs. After 1‐month observation period, angiography did not show significant stent‐induced stenosis. Histological evaluation revealed a completely endothelialized intravascular lumen and the absence of thrombus formation. The area of the intimal thickening induced by the FK506‐coated stents was significantly smaller than that induced by the non‐coated stents, whereas it was larger in the case of both the covered stents than that in the case of the bare stent. In conclusion, FK506 treatment of the self‐expandable, covered stents was confirmed to effectively inhibit intimal thickening, although the SPU film used for covering functioned as a drug carrier in addition to a scaffold for intimal formation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009