Bacteriostasis and disinfection - Tissue banking: tissue retrieval and processing - Chapter 21
Storage conditions and expiration periods must be supported by validation. Historical data, experience and documented literature are acceptable as evidence of validation. Any new processing or significant changes to existing processing are subject to pre-authorisation by the HTA.
21.4.1: Tissue without terminal antimicrobial processing
Tissue must be subjected to one of the following treatments, as soon as possible and within 24 hours of retrieval:
- antibiotic disinfection
- an alternative disinfection method
- frozen storage at –20°C or lower.
In the case of tissue taken from heart-beating donors in the operating theatre at the time of organ retrieval, this period may be extended to 48 hours.
21.4.2: Tissue with terminal antimicrobial processing
Tissue with terminal antimicrobial processing must be subjected to one of the treatments detailed in the above section within 24 hours of retrieval with a maximum of 72 hours following death. A summary of the guidance regarding temperature/time relationships contained in these guidelines is given in Tables 21.1 and 21.2.
Table 21.1 Temperature/time relationships for banked tissues from living donors
Table 21. 2 Temperature/time relationships for banked tissues from deceased donors
21.4.3: Positive bacteriology or mycology
It is the responsibility of the designated medical officer or designated microbiologist to develop written policies regarding the selection and conduct of tests for bacterial and fungal contamination and the acceptance criteria for specific tissues.
Where tissues are shown to carry viable bacteria or fungi they may be suitable for clinical use (e.g. skin grafts) depending on microbial types and densities of growth on culture. For other tissues the material may be approved for use provided that a validated antimicrobial processing technique is used.