Rodent Survival Surgery Procedures

Policy

The following statements apply to all survival surgical procedures performed on rodents. Any exceptions to these statements must be explicitly described, justified, and approved within the IACUC protocol.

Surgical Facilities

• The space in which survival surgery is to be performed must be clean and uncluttered.
• Rodent survival surgery must occur in a dedicated space, or a dedicated area within a space, that is not used for other purposes.
• Surgical spaces must be identified in the protocol and approved by the IACUC prior to use.

Pre-Operative Planning and Procedures

• Surgical procedures, including methods of instrument sterilization, description of technique, analgesic plan, monitoring frequency, and any associated secondary effects of the surgery must be described in the IACUC-approved protocol
  • Surgeries will be categorized as major or minor surgeries on a case-by-case basis as determined by the IACUC in accordance with the definitions above and The Guide.
  • In most cases, the IACUC considers rodent intracranial injections to be minor surgeries unless the injection is likely to create substantial impairment.
• Rodents do not generally require fasting prior to anesthesia.
• Preparation of the patient should include removal of hair and appropriate skin disinfection.
• All staff performing surgery must be appropriately trained in aseptic technique, instrument use, appropriate tissue handling, and wound closure methods. Staff performing surgery must be trained prior to performing any surgical procedures and then be certified by CLATR/veterinary staff prior to performing surgery independently. Additional training requirements can be found in the IACUC Policy: Surgery Training Requirements.
  • If the surgeon is also responsible for anesthesia, then the surgeon must also be appropriately trained for anesthesia administration and monitoring.
• Any procedure that would be painful for a human should be assumed to be painful for rodents. The use of peri-operative analgesia is encouraged; pre-emptive and multimodal analgesics (e.g. local anesthetics combined with systemic analgesics or a combination of non-steroidal anti-inflammatories and opioids) are preferred for survival surgery whenever possible. Withholding analgesics for painful procedures must be approved in the IACUC protocol and requires strong scientific justification. Specific analgesia recommendations can be found in the IACUC Policy: Analgesia in Research Animals.
• Animals must be confirmed to be at a surgical plane of anesthesia prior to beginning surgery. Depth of anesthesia should be assessed before starting and as needed throughout the surgery to assure a surgical anesthetic plane is maintained.

Intraoperative Procedures

• All surgery must be performed using aseptic procedures. Sterile instruments must be used, and a sterile surgical field should be used for most procedures.
  • In some cases, serial surgeries may be performed using a bead sterilizer on instrument tips between animals. A maximum number of 5 surgeries should be performed with this method. Instruments must be cool prior to subsequent use to prevent tissue damage.
  • The IACUC Guideline: Sterilization of Critical Items outlines appropriate sterilization methods for surgical supplies
• Appropriate surgical attire must be worn by the surgeon and assistants. Surgeon attire should typically include a face mask, clean lab coat or sterile surgical gown, and sterile surgical gloves. In some instances, the use of sterile gloves may not be necessary. Such cases must be justified in the investigator’s IACUC protocol and a description must be provided as to how the sterile field will be maintained.
• Tissue should be handled atraumatically to reduce post-operative pain and facilitate healing.
• Rodents under anesthesia are extremely susceptible to hypothermia which can lead to prolonged and delayed recoveries or even death. External heat support should be provided throughout anesthesia and until animals are fully recovered. Preferred heat sources are feedback-controlled, infrared, warm water, or air- circulating heating device. The use of electric heating pads that do not meet the above specifications and of heat lamps is strongly discouraged for anesthetized and/or recovering rodents due to the potential to cause burns. If used, methods must be in place to minimize risk of burns.
• Animals must be monitored appropriately throughout anesthesia and surgery. Dependent on species and procedure type/length, consider monitoring the animal’s vital signs (e.g., respiratory rate, heart rate, body temperature) and tissue hydration.

Post-operative Procedures

• Close surgical wounds using appropriate techniques and materials. Additional information regarding appropriate wound closure methods can be found in the IACUC Policy: Post-operative Monitoring and Surgical Closures in Research Animals.
• Animals must be monitored continuously with external heat support until recovered from anesthesia. Upon completion of surgery and discontinuation of anesthesia, move the animal to a warm, clean, dry area. Do not place anesthetized animals directly on bedding during the recovery period. Continue to monitor until the animal has exhibited the righting reflex and is appropriately responsive to stimuli.
• Post-operative analgesia should be provided as per the approved IACUC protocol.
• Post-operative monitoring must be performed as outlined in the approved IACUC protocol and should include regular assessments for species-specific indicators of pain, indications of incisional infections or dehiscence, evidence of continued bleeding, body weight, and hydration status. Any concerns must be promptly reported to Veterinary Services.

Record-Keeping

• Creating and maintaining a surgical record is required. The surgical record must include the date and nature of surgery, documentation of administration of analgesics, and documentation of post-operative monitoring.