Assessing the Impact of End-of-Life Processing on Reusable Medical Devices.

End-of-life (EOL) testing requirements for reusable medical devices continue to cause confusion in the medical device industry. Regulatory expectations from U.S. and European Union authorities differ, particularly regarding whether manufacturers must conduct EOL testing or if a cautionary statement in the instructions for use is sufficient. ISO 10993-1:2021 mandates biological safety evaluations for the maximum validated number of processing cycles. Similarly, ISO 17664-1:2021, regulation (EU) 2017/745, and Food and Drug Administration guidance require manufacturers to determine whether repeated processing causes degradation that could limit a device's usable life. However, these documents provide limited direction on how to perform such assessments, leaving a gap in standardized methodology. This study aimed to develop a practical and reproducible protocol for EOL evaluation, reflecting real-world clinical use and manufacturer-recommended processing instructions. The primary objective was to assess whether biological or chemical residues remained on devices after repeated use and processing. A theoretical estimate of 100 use and processing cycles was used, representing a reasonable service life based on routine clinical conditions. A simulated 100-cycle protocol, including soiling, cleaning, and sterilization testing, revealed negligible to nondetectable residual contaminants on both surrogate coupons and actual devices. These results suggest that even under worst-case conditions, devices can be processed effectively without substantial accumulation of contaminants, supporting the selected EOL threshold. This approach offers a reproducible framework for manufacturers to evaluate and validate EOL claims, addressing a critical regulatory and practical challenge.