ASTM F2942-13
(Guide)Standard Guide for in vitro Axial, Bending, and Torsional Durability Testing of Vascular Stents
Standard Guide for <emph type="bdit">in vitro</emph> Axial, Bending, and Torsional Durability Testing of Vascular Stents
SIGNIFICANCE AND USE
5.1 It is important to consider the durability of stent designs in deformation modes that are intended to model in vivo conditions. The appropriate amplitude and number of cycles in each of the modes has to be determined independently for the particular clinical use proposed for the stent. These tests do not replicate all varieties and aspects of the deployment process and the in vivo mechanical environment so they cannot be proofs of durability. Instead, the tests provide evidence of durability. The durability tests can also provide a means of assessing design, material or processing changes.
5.1.1 This guide might be useful for development testing, specification acceptance testing, and regulatory submission testing and filings as it provides a basic assurance that the tests are designed, executed, and reported in a suitable fashion.
5.1.2 If the tests are conducted using a well-defined FTF methodology, they can be useful in:
5.1.2.1 Potential design improvement through identification of better and worse geometries, materials, and manufacturing processes;
5.1.2.2 Understanding product durability by estimating the effects of changes in geometry, materials, or manufacturing processes;
5.1.2.3 Estimating the safety factor relative to the amplitudes and other factors in use conditions; and
5.1.2.4 Validating finite element analysis (FEA) and fatigue life models.
5.1.3 As stated in the scope, this guide is not intended to provide the in vivo physiologic deformation conditions that a vascular stent can be subjected. Reliable clinical data characterizing cyclic vascular deformation may be lacking for some indications. The user should develop and justify the boundary conditions (e.g., literature review, in vivo studies, cadaver studies, or modeling of stent vessel interaction) for the chosen durability bench tests. Additional conditions that may be considered include vessel calcification, vessel taper, eccentric lesions, deformation excursions (e.g., exer...
SCOPE
1.1 This guide includes three separate cyclic deformation durability guides related to vascular stents: bending, axial, and torsional.
1.2 This guide does not address flat plate, local crush durability, or multi-mode testing.
1.3 This guide applies to balloon-expandable and self-expanding stents fabricated from metals and metal alloys. It does not specifically address any attributes unique to coated stents (i.e., stent with a surface layer of an additional material(s)), monolithically polymeric stents, or absorbable stents, although the application of this standard to those products is not precluded.
1.4 This guide is applicable to testing of stent(s) (or a representative portion of a stent). While durability testing of coupon samples (e.g., a scaled-up portion of the stent structure) can provide useful information, it is not within the scope of this guide.
1.5 This guide applies to endovascular grafts (“stent-grafts”) and other conduit products commonly used to treat aneurismal disease, peripheral vessel trauma, or to provide vascular access. The information provided herein does not address all issues related to testing of these devices.
1.6 This guide applies to in vitro modeling of stent durability from non-radial arterial motions. Such motions may arise from musculoskeletal activities, including walking and breathing, and cardiac motion. ASTM F2477 addresses pulsatile (i.e., radial) durability of vascular stents.
1.7 This guide does not provide the in vivo physiologic deformation conditions for a vascular stent. It is incumbent upon the user of the standard to develop and justify these boundary conditions (e.g., literature review, in vivo studies, cadaver studies, or modeling of stent vessel interaction) in these durability bench tests. Additional conditions that may be considered include vessel calcification, vessel taper, eccentric lesions, loading excursions (e.g., exercise), and vessel remodelin...
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Standards Content (Sample)
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Designation: F2942 − 13
Standard Guide for
in vitro Axial, Bending, and Torsional Durability Testing of
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Vascular Stents
This standard is issued under the fixed designation F2942; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope considered include vessel calcification, vessel taper, eccentric
lesions, loading excursions (e.g., exercise), and vessel remod-
1.1 This guide includes three separate cyclic deformation
eling.
durability guides related to vascular stents: bending, axial, and
1.8 This standard does not purport to address all of the
torsional.
safety concerns, if any, associated with its use. It is the
1.2 This guide does not address flat plate, local crush
responsibility of the user of this standard to establish appro-
durability, or multi-mode testing.
priate safety and health practices and determine the applica-
1.3 This guide applies to balloon-expandable and self-
bility of regulatory limitations prior to use.
expanding stents fabricated from metals and metal alloys. It
does not specifically address any attributes unique to coated
2. Referenced Documents
stents (i.e., stent with a surface layer of an additional
2
2.1 ASTM Standards:
material(s)), monolithically polymeric stents, or absorbable
F2477 Test Methods forin vitro Pulsatile Durability Testing
stents, although the application of this standard to those
of Vascular Stents
products is not precluded.
2.2 Other Documents:
1.4 This guide is applicable to testing of stent(s) (or a
ASTM STP 588 Manual on Statistical Planning and
representative portion of a stent). While durability testing of
Analysis, R.E. Little, 1975
couponsamples(e.g.,ascaled-upportionofthestentstructure)
ISO 25539 Cardiovascular Implants–Endovascular Device-
canprovideusefulinformation,itisnotwithinthescopeofthis
s–Part 2: Vascular Stents
guide.
FDAGuidance Document #1545 “Non-Clinical Engineering
1.5 This guide applies to endovascular grafts (“stent-
TestsandRecommendedLabelingforIntravascularStents
grafts”) and other conduit products commonly used to treat
andAssociated Delivery Systems” (IssuedApril 18, 2010)
aneurismal disease, peripheral vessel trauma, or to provide
vascular access. The information provided herein does not
3. Terminology
address all issues related to testing of these devices.
3.1 Definitions of Terms Specific to This Standard:
1.6 This guide applies to in vitro modeling of stent durabil-
3.1.1 axial, adj—compression or tension of a stent and/or
ity from non-radial arterial motions. Such motions may arise
mock vessel along its longitudinal axis.
from musculoskeletal activities, including walking and
3.1.2 bending, adj—deformation on the longitudinal axis of
breathing, and cardiac motion. ASTM F2477 addresses pulsa-
a stent and/or mock vessel to achieve a specified stent radius of
tile (i.e., radial) durability of vascular stents.
curvature.
1.7 This guide does not provide the in vivo physiologic
3.1.3 fracture, n—the complete separation of a stent struc-
deformation conditions for a vascular stent. It is incumbent
tural feature.
upon the user of the standard to develop and justify these
3.1.4 mock vessel, n—a simulated vessel typically manufac-
boundary conditions (e.g., literature review, in vivo studies,
tured from an elastomeric material.
cadaver studies, or modeling of stent vessel interaction) in
3.1.5 radius of curvature, n—the inner, outer or centerline
these durability bench tests.Additional conditions that may be
bend radius of a stent.
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This test method is under the jurisdiction ofASTM Committee F04 on Medical
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and Surgical Materials and Devices and is the direct responsibility of Subcommittee For referenced ASTM standards, visit the ASTM website, www.astm.org, or
F04.30 on Cardiovascular Standards. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Aug. 15, 2013. Published September 2013. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/F2942-13. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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F2942 − 13
3.1.6 specimen, n—article consisting of an implantable de- characterization of the stent fatigue performance by applying
vice or a representative portion of an implantable device, that multiple deformation levels (i.e., loading amplitude) and con-
is tested according to this guide. ducting periodic inspections of the stent during testing to
obtain some test specimens with fractures and some witho
...
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