【国外标准】 Standard Test Method for Stent and Endovascular Prosthesis Kink Resistance

5.1 Upon deployment of a stent or endovascular prosthesis, the device is intended to maintain the patency of the vascular vessel. In order to maintain vessel patency, the device must deform within the in-vivo loading environment without a flow-limiting loss in lumen area. Kinking induces a severe, localized loss of lumen area, typified by a slot-like lumen shape. Device resistance to kinking can be evaluated through multiple test methods, with the appropriate selection depending on the device.5.2 The purpose of this standard is to outline test methods to address the resistance to kinking of stents and endovascular prostheses. In the case where no kinking is observed, the radius at which a predefined narrowing criterion (for example, 50 % diameter reduction) occurs may be considered as the kink radius of the device.5.3 When kink resistance properties are expected to vary along the length of the stent or endovascular prosthesis, testing should be performed at each of these sections.5.4 This standard is not intended to evaluate the kink resistance of devices other than stents, endovascular prostheses, and scaffolds, although the specific procedures outlined here may be used if applicable.1.1 This standard addresses the kink resistance of stents and endovascular prostheses (for example, stent grafts). The standard may also be applicable to scaffolds.1.2 Test methods presented herein address the kink resistance of stents and endovascular protheses when exposed to bending in a single plane. While concurrent influences (for example, torque) are recognized to influence kinking properties, test methods other than single-plane bending are not addressed.1.3 Test methods presented herein do not specifically address kink resistance of branched (for example, bifurcated) or multicomponent endovascular prostheses, but some aspects of this standard may be applicable to their application.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.