Significance and Use
5.1 The investigation of retrieved implantable medical devices and adjacent tissues can be of value in the assessment of clinical complications associated with the use of a specific prosthetic device design; can expand the knowledge of clinical implant performance and interactions between implants and the body; provide information on implant performance and safety; and thus further the development of biocompatible implant materials and devices with improved performance. Comparison of wear patterns and wear particle morphology observed with retrievals and those observed with in vitro joint simulator tests can provide valuable insight into the validity of the in vitro simulation.
5.2 A significant portion of the information associated with a retrieved implant is obtained with detailed studies of the device-tissue interface healing response. Appropriate methods are provided to facilitate a study of the particles in the tissues, and chemical analysis for the byproducts of degradation of the implant, and histologic evaluation of the cellular response to the implant.
5.3 For the analysis to be accurate, it is essential that the device and associated tissues be removed minimizing as best as possible alteration of their form and structure. It is also essential that the tissues be handled in such a way as to avoid microbial or viral contamination of the work place or the investigator. The tissue-device interface may need to be stabilized with chemical fixation prior to separation of the device from it’s in-situ position. It is also highly recommended to document detailed information about the tissue specimens, including location of extraction. Standard protocols for the examination and collection of data are provided for retrieval and handling of implantable medical devices, as well as for specific types of materials in relation to their typical applications. For particular investigational programs, additional, more specific, protocols may be required. If special analytical techniques are employed, the appropriate procedures must be specified.
5.4 In order to interpret the analysis of materials and tissues, it is also essential to capture a minimum data set regarding the reason for device removal, method of removal, method and timing preservation and clinical findings and laboratory studies documenting device performance.
5.5 Planning of the overall retrieval analyses prior to execution of any of the protocols or methods within this practice is essential to maximize the overall effectiveness of the analyses. The plan shall be based on initial observations from the available clinical information, tissues, and implants. Subsequently, the plan may need to be revised based on results obtained throughout the analyses. Due to the potential interferences described in Section 6, protocols and methods should be executed in a sequence such as to minimize the impact of interferences
5.6 Any destructive analysis of implants must be done so as to not destroy any features that may become the subject of litigation, in accordance with Practice E860. This standard recommendation should be applied in accordance with state or national regulations or legal requirements regarding the handling and analysis of retrieved implants and tissues.
Scope
1.1 This practice covers recommendations for the retrieval, handling, and analysis of implanted medical devices and associated specimens that are removed from human and animal subjects during revision surgery and at postmortem. This practice may be used for the analysis of any implant including inert, bioactive, resorbable, and tissue engineered products. This practice can also be used for analysis of specimens and fluids from in vitro tests, including those from wear tests and joint simulators. The aim is to provide guidance to minimize iatrogenic damage during the recovery and handling of the associated specimens which could obscure the investigational results. This practice is also intended to provide guidance as to gathering data at the proper time and circumstance.
1.2 This practice offers guidelines for the analysis of retrieved implants to limit damage to them, and to allow comparisons between investigational results from different studies. The protocols are divided into three stages, where Stage I is the minimum non-destructive analysis, Stage II is more complete non-destructive analysis, and Stage III is destructive analysis. Standard protocols for the examination and collection of data are provided for specific types of materials in relation to their typical applications. For particular investigational programs, additional, more specific, protocols may be required. If special analytical techniques are employed, the appropriate handling procedures must be specified. Note that regulations for handling of patient information, tissues, and retrieved devices will vary by geography.
1.3 This practice should be applied in accordance with pertinent regulations or legal requirements regarding the handling of patient data as well as the handling and analysis of retrieved implants and excised tissues, especially with regard to handling devices which may become involved in litigation, as in accordance with Practice E860. Note that regulations for handling of patient information, tissues, and retrieved devices will vary by geography
1.4 A significant portion of the information associated with a retrieved implant device is often at the device-tissue interface or in the tissues associated with the implant and related organ systems. Attention should be given to the handling of adjacent tissues, so as not to interfere with study of the particles in the adjacent tissue, a chemical analysis for the byproducts of degradation of the implant, or a study of the cellular response to the implant.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard may involve hazardous materials, operations, and equipment. As a precautionary measure, explanted devices should be sterilized or minimally disinfected by an appropriate means that does not adversely affect the implant or the associated tissue that may be subject to subsequent analysis. A detailed discussion of precautions to be used in handling of human tissues can be found in ISO 12891-1. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
