 to which it involves the exposure of tissues or body cavities. As stated in APHIS/AC Policy 3, “nonsurvival surgeries require neither aseptic techniques nor dedicated facilities if the subjects are not anesthetized long enough to show evidence of infection.” Any procedure that lasts longer than 12 hours and involves exposed tissues or body cavities presents a significant opportunity for infection to occur, and the risk increases with the length of the procedure (Knecht et al., 1987; McCurnin and Jones, 1985). Failure to use aseptic procedures in prolonged nonsurvival experiments increases the possibility that research data will be compromised and increases the risk of premature death due to sepsis. Either of those outcomes could entail the use of additional animals, which would be inappropriate for both ethical and regulatory reasons (see U.S. Government Principle III). It would also violate the requirements of the Guide and the AWRs for the provision of adequate veterinary care. The use of aseptic procedures also helps to ensure that students learn proper surgical technique and strengthens an institution’s ability to respond to public inquiries about the use of animals in research. When a preparatory survival surgical procedure is conducted to implant devices, such as a pedestal and chamber, it should be performed under aseptic
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conditions (AWR 2.31(d)(1)(ix); NRC, 1996). Most implanted devices and their carriers can be disinfected, but it might not be possible for some sensitive or delicate equipment, such as some types of microelectrodes (for further information on this topic see “Animal Care and Use Concerns Associated with Introduction of Probes into Neural Tissue” in Chapter 4). Whenever possible, it is advisable to sterilize or disinfect devices before their insertion into neural tissue. Because a typical neuroscience laboratory contains many other items, such as recording equipment, that cannot be sterilized, the full application of aseptic technique during a prolonged nonsurvival experiment is usually impossible. One approach to that problem is to use appropriate aseptic technique to create and maintain a local sterile field that includes any openings into major body cavities that are made during a prolonged nonsurvival session. Institutions should develop policies and guidelines to assist investigators in adapting aseptic surgical procedures to the laboratory setting. Topics that should be considered in preparing guidelines include preparation of the laboratory room, with particular attention to the site where surgery and recording will take place (for example, taking into account the relative locations of supply and exhaust ventilation ducts with respect to airborne contamination of the surgical field); preparation of the animal; preparation of the surgeon and any other experimenters who will come into proximity to the animal; instrument preparation; intraoperative monitoring; and training (APHIS/AC Policy 3; NRC, 1996, pp. 78–79). Neuroscientists can assist veterinarians and IACUCs in developing performance-based standards for monitoring the occurrence of deleterious effects by providing postmortem tissue specimens for histopathologic analysis.
Representative terms from entire chapter: