The field of medical device manufacturing continually evolves to enhance patient safety and device reliability. One key development in this area is the publication of ANSI/AAMI CN27:2021, a comprehensive standard that establishes general requirements for Luer Activated Valves (LAVs) used in intravascular applications. Published in December 2021, this standard is essential for harmonizing terminology, setting minimum requirements, and standardizing test methods for LAVs. It serves as the first foundational guide for manufacturers, regulatory bodies, and end users, offering clarity and consistency in the evaluation of these critical components.
The History and Challenges of Luer Activated Valves
Luer Activated Valves have long been integral to medical devices, especially in intravascular applications. Originally developed as needle-free connectors, they are now used in a variety of medical scenarios such as IV access, hemodialysis and close medication delivery systems. The shift towards using a valve compatible with standard fittings or syringes emerged as a response to the need for safer and more efficient, bi-directional fluid control systems. However, these LAVs presented unique challenges as the incorporation of a normally closed-valve design within an ISO-compliant luer distinguished them from the standard luer connectors.
Although there was guidance from ISO 80369-7 on how to evaluate that LAVs were compatible with standard male luer connectors, manufacturers adopted their own specifications to manage the complexities and risks associated with LAV connections. Furthermore, the variety of applications in how the LAV was used led to different product descriptions, performance claims, and instructions for use. As a result, this unfortunately caused confusion among end users which required manufacturers to educate the field on device capabilities and interactions.
Testing LAVs Prior to the Development of ANSI/AAMI CN27
Prior to the standardization of LAVs, testing was primarily conducted per the guidance of Annex A of ISO 80369-7. Within DDL, we have seen that there were two main approaches to showing LAV compatibility. The first approach was to conduct functional testing in guidance against the applicable ISO 80369-7 standard using the mating reference connector outlined in Annex C of ISO 80369-7. The second approach was similar but would involve the mating device (e.g. male luer lock syringe) as the reference connector to show compatibility. In addition, to the performance testing, a majority of our customers conducted the physical test method under ISO 80369-1 to show non-interconnectability characteristics rather than analyzing the specified dimensions from ISO 80369-7, Annex B.
Unfortunately, there were several issues with the guidance that ISO 80369-7 standard provided and the approaches above. As the standard mentions, most LAVs in the field were not compliant to the material requirement (i.e. Elastic/Flexural Modulus ≥ 700 MPa). As a result, conducting ISO 80369-1, Annex B non-interconnectability testing posed challenges if the material was soft as damage could be seen after one run of testing against an ISO 80369 metal reference connector. If the LAV was damaged and connected to the reference connector, it was difficult to determine if the damage caused the connection or if it was due to the design. In addition, the guidance did not account for other critical characteristics of the LAVs such as flow rate, priming/residual volume, and the performance while the valve was unactivated. For example, the performance testing outlined in ISO 80369-7 only challenged the LAV in the activated condition, but did not challenge the device in the unactivated condition to show that the valve was sealing properly. The ambiguity in how to properly characterize these critical elements of the LAVs to show patient safety highlighted the need for a standardized approach.
Key Features of ANSI/AAMI CN27:2021
1. Standardized Terminology and Requirements:
ANSI/AAMI CN27:2021 addresses the inconsistencies that previously existed in the market by standardizing the terminology and requirements for LAVs. This standardization includes precise definitions for terms like microbial ingress, activation number and duration, displacement, and power infusion capabilities. The uniformity in language helps ensure that all stakeholders, from manufacturers to regulators, have a clear and consistent understanding of device specifications.
2. Impact of Terminology on Performance Claims:
The standard recognizes the importance of precise language in regulatory and clinical contexts. For instance, due to the bi-directional nature of the device, the definition of fluid movement as “positive” or “negative” displacement affects how a device’s performance is communicated and understood by the end user. Such clarity allows manufacturers to better identify their device’s performance in order to make accurate, comparable performance claims on these devices now. The comparable performance claims not only promotes competition between manufacturers, but it also allows the end users to objectively determine which devices to use for their patients.
3. Harmonized Test Methods:
One of the critical contributions of ANSI/AAMI CN27:2021 is the harmonization of test methods. By establishing uniform test procedures, the standard enables reliable comparisons of performance claims among different LAV products. This is particularly crucial for making performance claims where consistent testing ensures accurate and meaningful labels. Although the standard outlines a uniform test procedure, there are some areas where testing will differ based on the specific application of the product. For example, manufacturers will still be responsible for understanding the longest intended use period and the number of intended activations/de-activations. Even with different applications, the harmonization of test methods allows manufacturers to mitigate subjective performance data, misleading claims and unintended clinical consequences.
Benefits for Manufacturers, Regulatory Agencies, and End Users
ANSI/AAMI CN27:2021 provides a comprehensive framework that benefits all stakeholders involved with LAVs. For manufacturers, the standard offers clear guidelines for designing and developing compliant devices, facilitating smoother interactions with regulatory agencies. Furthermore, due to the standardization of LAVs, manufacturers no longer have to conduct compatibility testing against specific mating devices to show functional compliance. Regulators, in turn, gain a robust tool for evaluating product safety and efficacy based on standardized criteria. End users, including healthcare professionals, benefit from consistent and reliable product information, reducing confusion and enhancing the safe use of LAVs.
Conclusion
The publication of ANSI/AAMI CN27:2021 marks a significant milestone in the standardization of Luer Activated Valves for medical devices. By establishing clear guidelines and harmonizing terminology and test methods, this standard provides a valuable resource for ensuring the quality and safety of LAVs used in intravascular applications. As the medical device industry continues to advance, adherence to ANSI/AAMI CN27 will be crucial in maintaining high standards of patient care and device performance.
For those involved in the design, regulation, or use of LAVs, understanding and implementing the requirements set forth in ANSI/AAMI CN27:2021 is essential for aligning with industry best practices and ensuring the safety of patients around the world.
For further information, please view the recent video with Matt Pasma, DDL’s Product & Materials Program Manager, in which he provides an overview of DDL’s Luer Activated Valve (LAVs) testing capabilities per the ANSI/AAMI CN27:2021 standard.
Please contact us for more information on LAVs testing, or if you need help on an upcoming test.
