1.1 This part of ISO 25539 specifes requirements for vascular stents, based upon current medical knowledge. With regard to safety, it gives requirements for intended performance, design attributes, materials, design evaluation, manufacturing, sterilization, packaging and information supplied by the manufacturer. It should be considered as a supplement to ISO 14630, which specifes general requirements for the performance of non-active surgical implants.NOTE Due to the variations in the design of implants covered by this part of ISO 25539 and in some cases due to the relatively recent development of some of these implants (e.g. bioabsorbable stents, polymeric stents), acceptable standardized in vitro tests and clinical results are not always available. As further scientifc and clinical data become available, appropriate revision of this part of ISO 25539 will be necessary.1.2 The scope of this part of ISO 25539 includes vascular stents used to treat vascular lesions or stenoses, or other vascular abnormalities. These devices might or might not incorporate surface modifcations of the stent such as drug and/or other coatings. Stents covered with materials that signifcantly modify the permeability of the uncovered stent are within the scope of ISO 25539-1. The stent design might dictate the need to address functional requirements identifed in both ISO 25539-1 and this part of ISO 25539.1.3 Delivery systems are included in this part of ISO 25539 if they comprise an integral component of the deployment of the vascular stent.1.4 Procedures and devices used prior to the introduction of the vascular stent, such as balloon angioplasty devices, are excluded from the scope of this part of ISO 25539.1.5 Some pharmacological aspects of drug-eluting stents are addressed in this part of ISO 25539, but this part of ISO 25539 is not comprehensive with respect to the pharmacological evaluation of drug-eluting stents.