23.3 Transportation conditions
For viable tissue the grafts should be placed into a transport solution with due regard to its effects on the ability of cells to propagate or metabolise. There must be adequate control of buffering capacity, osmolarity, tissue oxygenation. External contamination and desiccation must be avoided. The type, lot, manufacturer and the expiry date of the transport solution shall be documented. Transportation systems must be validated to show maintenance of the required storage temperature.
23.4 Bacteriostasis and disinfection
Tissue without terminal antimicrobial processing
Tissue must be subjected to one of the following treatments, as soon as possible, within 24 hours of retrieval:
- antibiotic disinfection
- an alternative disinfection method
- deep-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.
Tissue with terminal antimicrobial processing
Bone from living donors which is refrigerated within four hours of retrieval but not frozen until 24–48 hours after retrieval must be subjected to 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 Table 23.1.
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 providing a validated antimicrobial processing technique is used.