The Public Health Service requires that institutions base their animal care and use programs on the ILAR Guide for the Care and Use of Laboratory Animals. The UT Southwestern Institutional Animal Care and Use Committee (IACUC) must comply with the national standards and recommendations contained within the "Guide "

Policy:

Rodent survival surgery must be performed by a trained individual using aseptic procedures consistent with the Guidefor the Care and Use of Laboratory Animals.

Applicability:

This policy applies to rodent survival surgery.

Instructions:

A clean area of the room or laboratory must be dedicated for the surgical procedures and maintained as such during the surgical procedure.  Surfaces must be wiped with disinfectant before and after each procedure group to maintain cleanliness.  The surgical area must be covered with a clean drape.

Sterilization of Instruments:

All instruments, supplies, fluids, implants (i.e. metal, plastic, glass, etc.) that contact the animal, are placed in the wound, and/or placed in the surgical field must be sterilized prior to surgery.  Instruments must be cleaned prior to sterilization to remove organic material (i.e. blood, etc.) and surface contamination.  If instruments are wrapped, there must be a sterilization indicator such as autoclave tape placed on the outside of the pack to demonstrate adequate sterilization has taken place.  Sterilized instruments must be placed on a sterile surface to reduce the chances of contamination. 

Sterilization can be achieved by the following methods:

1.       Steam: 250° F, 15 psi, for 30 minutes.

2.       Hot-bead Sterilizer: Insertion in a bed of hot beads for 10 seconds works well for sterilization of instruments used in performing multiple survival surgeries.  However, this method only sterilizes the instrument tips.  The instruments must be free of organic material prior to contacting the beads.  Instruments also must be allowed to cool to avoid burning tissue. 

3.       Liquid sterilent:  Liquid sterilents are generally not recommended due to the long contact time required to sterilize equipment.  Examples of liquid sterilents include:

• Clidox (1 part base : 5 parts water : 1 part acid) or Alicide (minimum contact time of 6 hours; must be freshly made within less than 14 days),
•  2% Glutaraldehyde (minimum contact time of 10 hours; can be corrosive and irritating; commercial brands include Cidex and Abcocide),
• 8% Formaldehyde plus 70% Alcohol (minimum contact time of 18 hours),
• 6% Stabilized Hydrogen Peroxide (minimum contact time of 6 hours), and
• Sporocidin (minimum contact time of 7 hours).

Animal preparation:

• If the surgical procedure takes longer than 20 to 30 minutes, animals should be kept warm from induction of anesthesia to complete recovery, otherwise the animal should be kept warm from post-op to recovery.  Warming helps to reduce hypothermia and quicken the recovery time.  Examples of warming devices include:

• • slide warmers,
  • water recirculating heating pads (A clean drape should be placed between the animal and the heating pad.  Monitoring every 15 minutes is essential to ensure that the animal will not sustain a thermal injury from the heating pad.), and
  • heat lamps (Monitoring every 15 minutes is essential to ensure that the animal will not sustain a thermal injury from the heat lamp.  Animals must be kept at least 18 inches away from a heat lamp and they must be monitored constantly while under a heat lamp.  When using a heat lamp, it is recommended that a thermometer be used to monitor the animals core temperature.)
• Animals must be properly anesthetized prior to prepping.  An area twice the size of the expected surgical field should be prepped.
• Hair must be removed from the incision site with clippers or plucking, and then a depilatory cream may be applied.  If depilatory cream is used, the skin must be rinsed well with water to remove all cream residues that could cause dermatitis. 
• All loose hair and debris must be removed from the surgical area and rest of animal. 
• An ophthalmic ointment must be applied to prevent drying and damage to the cornea for all procedures.
• The skin must be cleaned with a standard surgical prep such as an iodophor (Betadine) or a chlorhexidine (Nolvalsan, Hibiclens).  Alcohol alone is not sufficient. 
• The animal must be draped with sterile covering to isolate the sterile incision area and create a sterile field that helps prevent contamination.  For small rodents, sterile gauze pads can be used.

Qualifications of the Surgeon:

Surgeons must have appropriate training to develop tissue-handling skills and avoid complications.  Good surgical technique requires asepsis, gentle tissue handling, minimal dissection of tissue, appropriate use of instruments, effective hemostasis and correct use of suture material. 

Intra-Operative Planning:

When planning rodent survival surgeries, the investigator must consider that rodent surgery management often involves multiple animals with repeated use of the same surgical instruments. Aseptic technique can be maintained using the same instruments with multiple animals if the following practices are used:

• Animals are presented in appropriately sized groups. This is dictated by the number of rodents that are safely anesthetized, prepped and placed in the surgical field. Other limits include experimental groupings and number of supplies included in each sterile pack.
• Each animal group is started with sterile instruments and supplies.  As the first animal is completed, the instruments and supplies are shifted to the next animal.  Between animals, a hot bead sterilizer or other form of sterilization must be used.
• Absorbable suture must be used for interior closure.
• Non-absorbable suture or wound clips must be used for exterior closure.
• Silk sutures must not be used for closure.

Postoperative Care:

Animals must be monitored for recovery from anesthesia.  They must be kept warm and dry to prevent hypothermia and must not be placed on bedding until they can maintain sternal recumbency.  Recovered animals must not be kept in the same cage as anesthetized animals.  Their proper hydration and nutrition must be assured.  Consult an ARC veterinarian if necessary.

Exterior closure materials must be removed between 7-14 days unless justification for a longer time period is approved in the protocol. 

Postoperative analgesia and antibiotics must be given in accordance with the approved IACUC protocol.

Record keeping:

The surgeon or assistant must keep records with the following information:

• IACUC approved protocol number
• Animal(s) identification (Note: Group records may be kept for rodents)
• Type of procedure
• Type of anesthetic including dose and route
• Type of analgesic, if given, including dose and route
• Type of antibiotic, if given, including dose and route (note: hamsters and guinea pigs are intolerant of many antibiotics)
• Postoperative monitoring (time, observations, date of clip removal, etc.)
• Complications
• Date of surgery
• A cage card must also indicate the date of surgery and procedure performed.

Exceptions:

Exceptions to this policy require a prior written request and approval by the IACUC. The exception request must provide adequate scientific justification for not following the policy.

Contact Information:

For any additional questions, please contact the IACUC Manager at 5-6420.