Purpose: The purpose of this policy is to clarify the requirements of the Principal Investigator (PI) and the Institution concerning survival surgical procedures performed on rodents. All investigators, laboratories, and facilities performing surgery on rodent species must adhere to the minimum standards addressed in this IACUC guideline.This policy is intented to explain in broad terms the requirements for survival surgery and links are provided for specific standard operating procedures that outline the steps in detail. The standards in this policy and in all referenced standard operating procedures must be adhered to unless otherwise justified in an IACUC approved animal use protocol.

Scope: This policy applies to all individuals performing survival surgery on rodents at the University of Oregon.

Background/Definitions: 

• Major Survival Surgery - Penetrates and exposes a body cavity, produces substantial impairment of physical or physiologic functions or involves extensive tissue dissection or transection. Examples include: laporotomy, thoracotomy, joint replacement, limb amputation.
• Minor Survival Surgery - Does not expose a body cavity and causes little or no physical impairment; this category includes wound suturing, peripheral vessel cannulation, percutaneous biopsy and headplate implantation. Animals recovering from these minor procedures typically do not show significant signs of postoperative pain, have minimal complications and return to normal function in a relatively short time. Some procedures that are slightly more invasive, such as drilling for optical fiber implants and creating cranial windows, have a slightly greater chance of post-op pain and infection, but are still in this category.
• Sterile - Free from all living organisms and their spores.
• Asepsis - A condition in which living pathogenic organisms are absent.
   

Policy: 

Any proposed Animal Use Protocol (AUP) that involves survival surgery is thoroughly reviewed by the IACUC to ensure that all of the following areas have been described in detail.

General requirements for rodent survival surgery include:

• Training of personnel
• Designated surgical area
• Use of approved anesthetic and analgesic agents
• Aseptic technique
  • Animal preparation
  • Surgeon preparation
  • Use of sterile instruments
• Intra-operative monitoring
• Post-operative care
• Completion of surgical and post-operative records

Training

• All appropriate trainings (Levels 1-4, and the 4 AALAS online modules) must be completed prior to initiaiting training of protocol specific surgeries. From the Guide: “Researchers conducting surgical procedures MUST have appropriate training to ensure that good surgical technique is practiced – that is, asepsis, gentle tissue handling, minimal dissection of tissue, appropriate use of instruments, effective hemostasis and correct use of suture materials and patterns (Brown et al, 1993; Heon et al. 2006).”
• When trained personnel are ready to perform surgeries independently, they must FIRST contact the Attending Veterinarian to schedule an assessment of their training and skills. Once the assessment is completed and the AV has signed off, the surgeon is free to perform AUP approved surgical procedures on their own.

Designated Surgical Area

• The specific location where surgeries will be performed must be indicated in the AUP.
• Whenever possible, a dedicated surgical space should be used. If a non-dedicated space is to be used, such as in the laboratory, the PI must provide justification of this departure in the AUP. Examples of justifications include specialized equipment requirements and variation in health status of animals undergoing surgery.
• Members of the IACUC must approve, in advance, all spaces where surgery will take place. Considerations include:
  • What is the nature of the procedure and the potential for physical impairment or post-operative complications?
  • Can the space be maintained in a manner that ensures cleanliness and minimizes unnecessary traffic and contamination from other activities being conducted in the room at other times?
  • The working surface (e.g. bench top, hood, etc.) and surrounding equipment (e.g. shelves, chairs, etc.) should be constructed of materials that are easily sanitizable.
  • The specific surgical area should not be located under air vents to minimize contamination and reduce the risk of postoperative infection. 
  • The immediate area should not be cluttered or used for storage of equipment unrelated to the surgical procedure. Storage containers should be easily sanitizable. Cardboard and Styrofoam should be avoided.
• Prior to initiating a surgical procedure, the immediate area should be dinsinfected with 10% bleach, 70% ethanol or other TeACS approved disinfectant: Eg., work surfaces; vaporizer, microscope and stereotax knobs; pen for writing; drill handle.
• Terrestrial Animal Care Services maintains two dedicated surgery suites that are available for rodent surgery:
  • 114 Streisinger
  • 149 LISB
• Additionally, there are numerous procedure rooms that are used by specific labs that conduct survival surgery. Eg: L153, L154.

Use of Approved Anesthetic and Analgesic Agents

• When in the planning phase of an AUP, you may refer to the IACUC Policy Anesthesia of Laboratory Animals for approved anesthetic and analgesic drugs, cocktails, doses, and route of administration.
• Every surgical IACUC protocol must describe a clear plan for providing in-date, pharmaceutical grade injectable or inhalation anesthetics and a description of how and when analgesics will be administered. In order to provide flexibility when performing the procedure, it is recommended to include a dose range and more than one option for the anesthetic and analgesic regimens when appropriate.
• Injectable anesthetics: Animals must be weighed prior to surgery to calculate the appropriate dose of anesthetics for the intended route of administration.
• Inhalation anesthetics: Inhalant anesthesia is the preferred method of general anesthesia for rodents. Vaporizers must be used to deliver inhalant anesthetics to rodents. Anesthetics must be scavenged with appropriate devices or methods. Anesthesia machines must be re-certified annually and tested for leaks when installed in new areas. The use of bell jars or drop method is prohibited for delivering anesthetics for any surgical procedure unless approved in your AUP.
• Analgesics: Surgery is considered a painful procedure; therefore administration of analgesics is required for any animal that undergoes a major survival surgical procedure. Analgesics must be administered before an animal is expected to be painful, not after significant signs of pain are noted. The goal is to have every animal patient maintained post-surgically in a pain-free state. Animals given pre-operative analgesia often require less anesthetic to reach a surgical plane, and thus may be more stable anesthetic patients. Pre-emptive analgesia is recommended. 

Aseptic Technique

• Successful aseptic technique involves adequate preparation of the area where surgery is to be performed, of the equipment and instruments that will come in contact with the animal, of the surgeon and of the animal itself. Careful pre-planning in these areas can significantly improve surgical outcomes.
• Consideration should be paid to whether the procedure requires complete aseptic procedures or a "tips-only" approach. It will be detailed in the AUP which approach is warranted. You must follow the procedures outlined as such.

Animal Preparation

• See additional details in the ACS Surgery Pre- and Post-operative Care of Rodents SOP.
• Anesthetize and prepare the animal in accordance with the details in the IACUC-approved AUP.
• Apply plain ophthalmic ointment to both eyes to prevent corneal desiccation.
• Restrain the animal as needed. Avoid overstretching of limbs. Use padding under animal to avoid excessive pressure.
• Remove hair from the surgical site using clippers, depilatory cream or plucking.
• Perform a surgical preparation of the incision site:
  • Use povidone iodine (Eg. Betadine) or chlorhexidine (Eg. Nolvasan) alternating with alcohol.
  • Start with alcohol and perform 3 alternating scrubs of the area as described in the SOP.
  • If you finish with an antiseptic, it must be the "solution" not the "scrub". Disinfectant "scrub" has a cleansing agent that can be irritating when left on skin.
  • Avoid excessive wetting of the animal. This can lead to hypothermia.
• Consider covering the rodent with a sterile drape to avoid contamination of the incision, instruments and supplies.Transparent drapes are recommended in order to continuously monitor breathing. “Press ‘n’ Seal®” wrap may be used in place of a sterile drape. These have been shown to be nearly sterile when taken directly from the packaging, are clear to allow good patient monitoring and visualization, and help to support thermoregulation by creating a sealed barrier around the patient. Using this method, the surgical incision can be made directly through the wrap and patient’s skin. This step is mandatory when a body cavity is being opened.

Surgeon Preparation​

• All personnel taking part in the surgery must:
  • Wear clean lab coat, scrubs, or appropriate disposable gown.
  • A sterile gown is not required unless specified in the AUP.
  • Wear appropriate face mask.
  • Scrub hands with antiseptic soap.
  • Wear sterile gloves (sterile surgical gloves, autoclaved nitrile gloves or HP-PA disinfected gloves. See Sterile Glove Donning SOP).
  • Move carefully to avoid contamination of the surgical location.

Use of Sterile Instruments​

• All instruments must be cleaned and sterilized prior to the beginning of each surgical session. Alcohol alone is NOT a sterilant.
• If instruments are to be used for multiple surgeries in a single session, they must be sterilized between animals. Hot bead sterilizers are recommended in these cases.
• Autoclaves are available in Streisinger and LISB. See Streisinger Autoclave Use and LISB Autoclave Use SOPs.
• Once you've donned sterile gloves, arrange the sterile instruments so that the tips are within a sterile field and the handles are outside the sterile field. Do not contaminate the sterile tips of the instruments during this process. Instrument tips must be maintained within this sterile field throughout the surgery.
• Sterile supplies such as gauze and cotton tipped swabs should also be placed on the sterile field.
• Only the sterile tips of instruments, sterile gauze or sterile swabs should touch the actual surgical site.

Intra-operative Monitoring

• The anesthetist/surgeon should continuously monitor the animal’s basic physiological function for the duration of the procedure—from induction through recovery.
• Common monitoring parameters to assess anesthetic depth are: response to surgical manipulation, tail/toe pinch, respiratory rate/quality, mucous membrane color, heart rate.
• Many monitoring devices are difficult to use on mice but may be required with certain procedures.
• Changes in vital signs may require modifications in anesthetic dosing.
• If, at any time, an animal begins to respond to pain or attain an anesthetic depth that is too light, stop the procedure and adjust the inhalant anesthetic level or give a supplemental dose of injectable anesthetic. Re-confirm anesthetic depth before resuming work.
• Anesthetized animals must not be left unattended for the duration of the anesthetic episode.
• It is required that specific monitoring parameters be checked a minimum of every 15 minutes during anesthesia. See the ACS Surgical Record Procedure SOP for details and the form.
• Which parameters will be monitored must be detailed in the AUP and followed with each surgery.

Post-operative Care​

• Once anesthesia is complete, animals should be placed into a clean recovery cage (preferably with clean paper towel or cage liner on bedding) in sternal or lateral recumbency.
• The animal must be observed until they have regained postural reflexes and are ambulatory.
• You can place the cage in a recovery unit located in rooms L144 and L149. Alternatively, the animal can be observed in the recovery cage in the surgery area with a supplemental heat source. 
• Recovering animals should not be in the same cage as awake animals.
• During anesthetic recovery, the animal’s body temperature should be supported with an appropriate, well-maintained heating device (e.g. recovery unit, slide warmer, recirculating water heating pad, or heat lamp). To avoid burning, be cautious that the heating device is not too hot or too close to the animal. If a heat lamp is used, the rodent cage should be covered with a solid lid (e.g. microisolator top). There should always be a cooler location in the enclosure to which the animal can escape if they become too warm.
• Administer fluids and analgesics according to the AUP.
• Return to normal eating and drinking can be hastened by offering highly palatable Nutrical and moist food placed in a petri dish on floor of cage. See the TeACS Soft Food Administration SOP
• Recovered animals can be returned to their regular housing room when alert and active.
• Post-operative animals must be monitored daily for signs of pain, distress, discomfort and weighed and findings recorded on the Individual Health History Form for a minimum of 3 days according to the AUP.
• In the event an animal experiences unexpected post-operative complications, you should follow the ACS Animal (Sick/injured) Emergency SOP and immediately contact the AV. If an animal dies during surgery or in the immediate post-operative period, please notify the AV. In the event of unexpected deaths, it may be necessary to modify a surgical procedure or anesthetic / analgesic protocol.
• In the event that multiple major survival surgeries are performed, the animal will be allowed to recover for a minimum of 2 days.

Completion of Surgical and Post-operative Records

• When conducting survival surgery, you must follow the ACS Surgical Record Procedure SOP.
• Both the Individual Health History Form and the Surgical Record Form must be completed for each animal unless an alternative record-keeping system is approved in your AUP.
• For a minimum of 3 days post-op, make notes of observations, weight and treatments given - include medication, route, volume, and initial the chart.
• Only lab members or TeACS staff who have been trained to recognize signs of pain, distress and discomfort in rodents are permitted to perform the post-operative monitoring and to make a distinction about whether or not an animal requires additional pain medication.
• Identify each animal's cage with a pink post-op card.
• All medical records should be placed in the folder outside of the housing room where the animal is placed.

Approvals: 

approved by	date
IACUC Committee	1/11/18

 

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