Medical devices utilizing animal tissues and their derivatives - Part 1: Application of risk management (ISO 22442-1:2015); German version EN ISO 22442-1:2015
1Key Takeaways
This part of EN ISO 22442 specifies requirements and guidelines for the application of risk management for medical devices that use animal tissues and their derivatives. It is part of a series of standards dealing with animal tissues and complements parts 2 (control of procurement, collection and handling) and 3 (valid…
2Expert Interpretation
An in-depth interpretation of EN ISO 22442-1:2015, the risk management standard for medical devices using animal tissue and its derivatives, covers TSE risk classification, tissue infectivity assessment, production process control, and clinical application risk management requirements, providing medical device manufacturers with a complete compliance implementation plan.
Overview of the EN ISO 22442-1:2015 Standard Framework
EN ISO 22442-1:2015, as the core standard for risk management of medical devices using animal tissue and its derivatives, replaces the 2008 version and provides manufacturers with a systematic risk management framework. This standard applies to all medical devices using animal tissue and its derivatives, with a focus on risk control for transmissible spongiform encephalopathies (TSEs).
TSE Risk Grading Management System
Annex D of the standard details a three-tier classification system based on tissue infectivity, providing a scientific basis for risk assessment:
| Risk Category | Infectious Characteristics | Typical Tissue Types | Risk Management Requirements |
|---|---|---|---|
| Category A | Highly Infectious Tissues | Central Nervous System Tissues | Prohibited Use or Extremely Strict Control |
| Category B | Low Infectious Tissues | Lymphoid Tissue, Peripheral Nerve | Strict Source Control + Inactivation Verification |
| Category C | No Infectiousity Detected | Muscle, Bone, Reproductive Tissue | Standard Quality Control Measures |
Key Technological Innovations and Evolution
Compared to the 2007 version, the 2015 version achieves significant technological upgrades in the following areas:
1. Risk Quantification Assessment Model: This introduces an exposure assessment approach, requiring manufacturers to accurately calculate the amount of animal-derived material required for a single product and assess the potential accumulation of TSE pathogens during the production process.
2. Application Route Risk Grading: This establishes a four-tiered risk control strategy based on the application route, from central nervous system exposure (highest risk) to intact skin application (lowest risk).
3. Scientific requirements for inactivation validation: Explicitly require that the inactivation/elimination process must be scientifically validated, including the basis for the selection of model TSE pathogens, the calculation method of the reduction factor, and the determination of key process parameters.
Tissue-specific infectivity data analysis
The standard establishes a detailed tissue infectivity database based on a large amount of experimental data:
| Tissue Type | vCJD Infectivity | BSE Infectivity | Scrapie Infectivity | Risk Management Recommendations |
|---|---|---|---|---|
| Brain Tissue | +++ | +++ | +++ | Use Prohibited |
| Spinal Cord | +++ | +++ | +++ | Use Prohibited |
| Lymphoid tissue | ++ | ++ | ++ | Strict control |
| Peripheral nerve | + | + | + | Inactivation verification |
| Skeletal muscle | - | ± | + | Source control |
Risk control strategy for clinical application
Risk control requirements based on application route:
a) Highest risk level: Products contacting the central nervous system (including intraocular applications) require the use of Category C tissue and a validated inactivation process.
b) High Risk: For products that contact the circulatory system or parenteral applications, the use of strictly processed Category B tissue is permitted.
c) Medium Risk: For products applied to intact mucous membranes, the source of the tissue must be ensured to comply with geographical origin and animal species requirements.
d) Low Risk: For products applied to intact skin, standard quality control is sufficient.
Implementation Recommendations and Compliance Path
Medical device manufacturers should follow the following path to implement EN ISO 22442-1:2015:
1. Establishment of a Source Control System: In accordance with the requirements of ISO 22442-2, a complete animal tissue source traceability system should be established, including animal species, geographical origin, breeding conditions, and slaughter and processing controls. 2. Inactivation Process Validation: Conduct scientific inactivation validation studies in accordance with ISO 22442-3 requirements, select appropriate model pathogens, and calculate accurate reduction factors. 3. Risk Assessment Documentation: Develop complete risk assessment documentation, including tissue infectivity assessment, exposure calculation, application route analysis, and overall risk assessment. 4. Quality System Integration: Integrate animal-derived material risk management into the ISO 13485 quality management system to ensure full process control. With the advancement of biotechnology, the risk management of animal tissue medical devices is showing the following trends: Advances in Detection Technology: The development and application of new, highly sensitive PrPTSE detection methods provide technical support for improving the accuracy of risk assessments. Global Harmonization: Harmonize standards with international organizations such as the WHO and OIE to promote globally unified risk management requirements.
New Materials Application: Research on the standard adaptability of new materials such as gene-edited animal tissues and tissue engineering products.
EN ISO 22442-1:2015, as the benchmark standard for risk management of animal tissue medical devices, provides scientific and reliable technical specifications for industry development. Manufacturers should have a deep understanding of the standard requirements and establish a comprehensive risk management system to ensure product safety and effectiveness.