ISO/DIS 25539-4

Cardiovascular implants -- Endovascular devices

Implants cardiovasculaires -- Dispositifs endovasculaires

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 25539-4
ISO/TC 150/SC 2 Secretariat: ANSI
Voting begins on: Voting terminates on:
2020-12-07 2021-03-01
Cardiovascular implants — Endovascular devices —
Part 4:
Application of ISO 17327-1 for coated endovascular devices
ICS: 11.040.40
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
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This document is circulated as received from the committee secretariat.
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ISO/DIS 25539-4:2020(E)
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PROVIDE SUPPORTING DOCUMENTATION. ISO 2020
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ISO/DIS 25539-4:2020(E)
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ii © ISO 2020 – All rights reserved
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ISO/DIS 25539-4:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Requirements for coating properties ............................................................................................................................................. 2

4.1 Vascular stents ........................................................................................................................................................................................ 2

4.1.1 Drug coatings ...................................................................................................................................................................... 4

4.1.2 Non-drug coatings .......................................................................................................................................................... 8

4.1.3 Chemistry-related surface modifications ................................................................................................10

4.2 Endovascular Prostheses ............................................................................................................................................................11

4.3 Vena Cava Filters ................................................................................................................................................................................11

Bibliography .............................................................................................................................................................................................................................12

© ISO 2020 – All rights reserved iii
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ISO/DIS 25539-4:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

iso/ foreword .html.

ISO 25539-4 was prepared by Technical Committee ISO/TC 150, Implants for surgery, Subcommittee

SC 2, Cardiovascular implants and extracorporeal systems.

A list of all parts in the ISO 25539 series can be found on the ISO website. ISO 25539 consists of the

following parts, under the general title Cardiovascular implants — Endovascular devices:

— Part 1: Endovascular prostheses
— Part 2: Vascular stents
— Part 3: Vena cava filters
— Part 4: Application of ISO 17327-1 for coated endovascular devices

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
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ISO/DIS 25539-4:2020(E)
Introduction

This standard specifies the application of ISO 17327-1:2018, Non-active surgical implants — Implant

coating —Part 1: General requirements to coated endovascular prostheses, vascular stents, and vena

cava filters. Examples of coatings include: drug coatings (i.e. eluting and non-eluting), non-drug

coatings (i.e. absorbable and non-absorbable), and chemistry-related surface modifications (i.e. oxide

(e.g. TiO2) and non-oxide (e.g. amorphous silicon carbide, diamond-like carbon)). ISO 17327-1 has

a broad scope, including all nonactive surgical implants, and thus only some of the requirements in

that standard are applicable to coated endovascular devices. ISO 25539-4 clarifies how ISO 12417-1,

ISO 17137, ISO 25539-1, ISO 25539-2, and ISO 25539-3 satisfy the requirements of ISO 17327-1. A device

evaluation strategy is needed to identify the appropriate evaluation of specific coated devices.

It is recognized by this ISO committee that many coated endovascular devices have been shown to be

safe and effective in clinical use. This standard is not intended to require additional evaluation of these

devices to be in compliance with this standard as the testing would not provide useful information

regarding the expected clinical performance of the device. Manufacturers may rely on historical

data gathered under the guidance of ISO 25539-1, ISO 25539-2, and ISO 25539-3. Similarly, for device

modifications or changes in intended clinical use, this standard is not intended to require additional

evaluation of any aspects of the device that are not expected to change clinical performance.

© ISO 2020 – All rights reserved v
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DRAFT INTERNATIONAL STANDARD ISO/DIS 25539-4:2020(E)
Cardiovascular implants — Endovascular devices —
Part 4:
Application of ISO 17327-1 for coated endovascular devices
1 Scope

Part 4 of ISO 25539 specifies the appropriate application of ISO 17327-1:2018, Non-active surgical

implants — Implant coating —Part 1: General requirements, to coated endovascular prostheses, vascular

stents, and vena cava filters. Part 4 of ISO 25539 should be considered as a supplement to ISO 25539-1,

ISO 25539-2, ISO 25539-3, ISO 12417-1 and ISO 17137.

The following coatings are within the scope of ISO 17327-1 and addressed in this standard for

endovascular devices: drug coatings (eluting and non-eluting), non-drug coatings (absorbable and

non-absorbable), and chemistry-related surface modifications (oxide(e.g. TiO ) and non-oxide(e.g.

amorphous silicon carbide, diamond-like carbon)).

This standard is not applicable to coated delivery systems or coated ancillary devices (e.g. guidewires),

as these coatings are not within the scope of ISO 17327-1, which is specifically directed to implant

coatings.

This document is not applicable to coverings of endovascular devices; however, if the covering of a

device is coated it is within the scope of this part of ISO 25539.

This standard does not address the requirements for, and the evaluation of, viable tissues and non-

viable biologic materials used as implant coatings.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references below, only the edition cited applies.

ISO 17327-1:2018, Non-active surgical implants — Implant coating — Part 1: General requirements

ISO 25539-1:2017, Cardiovascular implants — Endovascular devices — Part 1: Endovascular prostheses

ISO 25539-2:2020, Cardiovascular implants — Endovascular devices — Part 2: Vascular stents

ISO 25539-3:2011, Cardiovascular implants — Endovascular devices — Part 3: Vena cava filters

ISO 12417-1:2011, Cardiovascular implants and extracorporeal systems – Vascular device-drug combination

products

ISO/TS 17137:2014, Cardiovascular implants and extracorporeal systems -- Cardiovascular absorbable

implants
3 Terms and definitions
3.1
Implant coating
Refer to ISO 17327-1.

For the purposes of this document, the terms and definitions in the normative references apply.

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ISO/DIS 25539-4:2020(E)
4 Requirements for coating properties

Clauses 4.1, 4.2, and 4.3 address the requirements as related to ISO 17327-1 for vascular stents,

endovascular protheses and vena cava filters, respectively. The coating types identified in Table 1 are

addressed in this standard. A device may have multiple coatings each of which could be identified as

different or multiple coating sub-types. For example, a drug eluting stent with an absorbable matrix

would fit into eluting and absorbable coating sub-types.
Table 1 — Coating Types Addressed by this Standard
Coating Category Coating Sub-Type I Coating Sub-Type II
Drug Eluting Non-eluting
Non-Drug Absorbable Non-absorbable
Chemistry-related surface modifications Oxide Non-oxide

All evaluations identified in ISO 17327-1 might not be appropriate for all coated endovascular

prostheses, vascular stents and vena cava filters. The device evaluation strategy described in

ISO 25539-1 and ISO 25539-2 guides the development of the rationale for the testing selected to evaluate

the endovascular device based on the requirements of the device design and potential failure modes.

Evaluation of generic coating properties listed in ISO 17327-1 and identified as necessary by the device

evaluation strategy shall be completed. Evaluation of coating properties listed in ISO 17327-1 deemed

as not necessary by the device evaluation strategy do not need to be completed.

Due to the broad scope of ISO 17327-1, some terminology and associated requirements in that standard

are appropriate for other types of nonactive surgical implants, but inconsistent with standard

terminology and requirements for endovascular devices. In these cases, more relevant terminology and

requirements are presented in this standard and correlated to the requirements in ISO 17327-1. This

includes the requirements for the consideration of adhesion strength and coating abrasion resistance.

For the coatings and implants addressed in this standard, these generic coating properties are

evaluated by other tests. For example, adhesion strength is defined in ISO 17327-1 as the “load per unit

area required to separate the coating from the substrate.” For the coatings and implants addressed in

this standard, coating adhesion is considered part of the assessment of maintenance of coating integrity

which is evaluated through other means such as simulated use, durability, and particulate generation.

Thus, the specific characterization of the adhesion strength (i.e. load per unit area required to separate

the coating from the substrate) is not required. Similarly, coating abrasion resistance is considered part

of the assessment of maintenance of coating integrity.

For chemistry-related surface modifications on the devices within the scope of ISO 25539, coating

coverage integrity evaluation is addressed through corrosion testing, while corrosion resistance is not

identified as a generic coating property in ISO 17327-1.

Evaluation of porosity and pore size, surface wettability, and surface texture are generally not

applicable to coatings on endovascular devices. The potential need to evaluate these properties would

be identified through the device evaluation strategy.
4.1 Vascular stents

In order to conform to the requirements of ISO 17327-1, evaluation of drug coatings, non-drug coatings,

and chemistry-related surface modifications of stents shall be conducted for the properties as outlined

in Tables 3, 4, and 5, respectively. The standards listed in Tables 3, 4, and 5 refer to the dated versions in

clause 2. A description of column headings associated with Tables 3, 4, and 5 is provided in Table 1. The

available test methods (non-mandatory) that may be of use in meeting the applicable requirements are

provided in Tables 3, 4, and 5.
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ISO/DIS 25539-4:2020(E)
Table 2 — Description of Table 3, 4, and 5 column headings
Design Attributes Coating Type
ISO 17327-1 from Other Relevant
Coating Sub-Type I Coating Sub-Type II
Generic ISO Standards
Coating Corresponding to
Applicable Applicable Applicable Applicable
Property Generic ISO 17327-1
Requirement Test Method Requirement Test Method
Coating Properties
The requirements
identified in the ap-
plicable ISO standard
that correspond to The available
the generic coating test methods
property or design at- that may be of
Each generic
tribute. Requirements use in meeting
coating Design attributes
that do not align with the applicable
property from identified in the appli-
the ISO 17327-1 gener- requirement.
ISO 17327-1 cable ISO standards
ic coating properties These test see column 3 see column 4
to be consid- that correspond to the
are not listed. Some methods are
ered for char- ISO 17327-1 generic
requirements indicate not mandatory
acterization or coating property.
the need to consider and are not
evaluation.
the evaluation of a limited to ISO
property, while others standardized
indicate that the prop- methods.
erty shall be evaluat-
ed, as required by the
applicable standard.
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ISO/DIS 25539-4:2020(E)
4.1.1 Drug coatings

Table 3 — Applicable requirements and test methods (informative) related to drug coatings

Design Attributes from Other Drug Coating Type
ISO 17327-1
Relevant ISO
Generic Eluting Non-Eluting
Standards Correlated
Coating
to Generic ISO 17327-1 Coat- Applicable Applicable Applicable Applicable
Property
ing Properties Requirement Test Method Requirement Test Method
ISO 25539-2
6.7 Drug-Eluting Stent
• Ability of the stent to
consistently contain the
desired type and amount of
drug
• Conformance of the
residual drug quantity to
design specifications for
drug-eluting stents and not
for drug containing stents
• Freedom of the drug(s)
from deleterious impurity
and degradant levels at
ISO 25539-2 ISO 25539-2
manufacture and with
8.1 Design Eval- 8.1 Design Eval-
storage
uation – General uation – General
ISO 12417-1
ISO 12417-1 ISO 12417-1
5.2.2-d Matrix
7.2.4.3.4 Drug 7.2.4.3.4 Drug
Use applicable Use applicable
content content
Chemical • Conformance of the matrix standa
...