| abstract |
As a therapy for angiostenosis, angioplasty (PTA, PTCA), in which a small balloon is inflated in a blood vessel to dilate the vessel, has been widely carried out as a minimally invasive treatment. In this therapy, however, repeated stenosis (restenosis) occurs at a high possibility. As a means of lessening the restenosis, procedures using indwelling stents become popular in recent years. However, it is reported that restenosis occurs at a frequency of about 20 to 30% even in these treatments using indwelling stents. Although attempts have been thus made to coat a stent with a drug regulating obstruction, stenosis still arises at a high frequency in such cases at the present stage. At least two layers involving a layer containing an immune suppressant and a layer containing an antiinflammatory agent are formed on the surface of an indwelling stent. |