| abstract |
As a therapy for angiostenosis, angioplasty (PTA, PTCA), in which a small balloon is inflated in a blood vessel to expand the vessel, has been widely practiced as a minimally invasive treatment. In this therapy, however, repeated stenosis (restenosis) occurs at a high incidence. In order to reduce the restenosis rate, procedures that use indwelling stents have gained popularity in recent years. However, restenosis has been reported in about 20% to 30% of stent placement cases. Although attempts have been made to coat the stent with a drug that regulates occlusion, stenosis still occurs at a high frequency. At least two layers including an immunosuppressant-containing layer and an antiinflammatory agent-containing layer are provided on the surface of an indwelling stent. |