Guidelines for Rodent Survival Surgery

Guidelines for the performance of rodent survival surgery are based on the 1996 edition of the National Institutes of Health (NIH) Guide for the Care and Use of Laboratory Animals and 9 CFR, the Animal Welfare Act (AWA).

The NIH Guide provides the following guidelines for rodent surgery:

(1) Major survival surgery on rodents does not require a special facility but should be      performed using sterile instruments, surgical gloves, and aseptic procedures to      prevent clinical infections.
(2) Major survival surgery is defined as any surgical intervention that penetrates a      body cavity or has the potential form producing a permanent handicap in an      animal that is expected to recover.
(3) Training in aseptic procedures should be provided for those who require it.

The Animal Welfare Act states: "Non-major operative procedures and all surgery on rodents do not require a dedicated facility but must be performed using aseptic procedures. Operative procedures conducted at field sites need not be performed in dedicated facilities but must be performed using aseptic procedures.."

The following guidelines are provided by the SUNY-Stony Brook Institutional Animal Care and Use Committee (IACUC) to assist investigators in complying with the NIH guidelines and the Animal Welfare Act.

Surgical Facility

• A separate facility for rodent surgery is not required. The area where surgery will take place must be disinfected prior to the surgical session (see Table 1). A clean or sterile towel or drape should be placed on the bench top to define the surgical area.
• The area in which the surgery is to be conduct must be clean, uncluttered and free from overhanging objects and chemicals. The area should be away from major traffic areas, doors and windows.
• Devices or equipment (e.g. animal restraining devices, monitoring equipment, stereotaxic devices, etc.) which are required to be in the surgical field must also be disinfected in order to reduce or potentially eliminate infectious organisms (see Table 2).
• The designated area should not be used for other activities during the surgical procedures.

Preparation of Surgical Instruments

• Instruments, implantable devices (catheters, trocars, osmotic pumps, telemetry) and suture material must be sterilized by using any of the methods listed in Table 2.
• The method of sterilization selected will depend upon the composition of the materials and the equipment available. Proper sterilization techniques (including the use of sterilization monitoring devices, if applicable) must be followed to assure that consistent results are obtained.
• The appropriate selection of suture material is essential. Characteristics and uses of different materials are listed in Table 3.
• DLAR can provide steam sterilization of instrument packs for investigators on a recharge basis.

Preparation of the Animal

• The fur must be removed from the surgical site, either by clipping, plucking or using a depilatory.
• An area approximately 15% larger than the area of the incision should be prepared.
• All loose fur should be vacuumed away, or sticky tape may be used.
• Clean and aseptically prepare the surgical site by using an appropriate scrubbing technique (e.g. scrubbing in gradually enlarging circular pattern from the interior of the shaved area to the exterior) and an effective disinfectant (e.g. alternating Betadine ? or Nolvasan™ and alcohol scrubs X 3). See Table 4.
• The surgical area should be draped using either standard draping material or Steri-Drapes™.
• It is recommended that animals be placed on a water re-circulating heating blanket or pads during surgery to prevent hypothermia.
• It is recommended that ophthalmic ointment be placed in the anesthetized animals’ eyes to prevent drying of the cornea.

Preparation of the Surgeon

• The surgeon must wear a clean lab coat, mask and sterile gloves. A sterile surgical gown and head cover are recommended for major or prolonged surgeries.
• The surgeon must scrub their hands before putting gloves on.

Maintaining a Sterile Field

• The surgeon should restrict his/her contact to the surgical site and previously sterilized equipment until the incision is closed.
• Use only sterile solutions and disinfect tops of containers before use.
• Do not let catheters or implants become contaminated.
• Use a sterilized area (surgical tray or sterile gauze) to rest materials on when not in use.
• Manipulation of tissues within the surgical field with gloved hands should be avoided; the ends of sterilized instruments should be used to manipulate and handle tissues.
• The exteriorizing of organs should be avoided if possible, but if required, should be placed on the sterile drape.
• Gloves must be changed if they come in contact with a non-sterile surface.
• Two separate sets of surgical instruments can be used – one set for incising and manipulating skin and another for manipulating deeper tissues.

Multiple Surgeries in a Single Session

• Animals, materials and area preparation must be completed prior to donning sterile gloves.
• Instruments and gloves may be used for a series of similar surgeries provided they are appropriately cleaned and disinfected between use (see Table 5). Note: alcohol alone is not an acceptable disinfectant.
• If using a glass bead sterilizer, recognize that only the tips of the instruments are sterile and tips must be allowed to cool before touching tissue.
• How often will the animals be monitored and by whom?
• Alternating 2 sets of sterile instruments is a method to provide the necessary time for instruments to sit in disinfectant for the required time. Instruments must be thoroughly rinsed with sterile saline prior to re-use.
• For major surgeries it is highly recommended that sterile gloves be changed between animals.

Post-operative Recovery

• The animal should be kept warm by the use of re-circulating water blankets, warming blankets, or lamps. Electric heating pads should not be used as they can cause thermal burns.
• If fluids are given, the fluids should be warmed.
• Animals recovering from anesthesia should be monitored and rotated from side to side every 15 minutes until they are able to maintain sternal recumbancy. After full recovery, animals may be returned to their home cage.
• If surgery is to be performed on either lactating females or on pre-weaned pups, please contact the DLAR veterinary staff to discuss methods for re-introduction of pups to the dam.

Post-operative Care

• Animals should be monitored on a daily basis as described in the approved IACUC protocol. Analgesics are to administered, per protocol. If unanticipated post-operative pain is observed, consult with the DLAR veterinary staff for pain management.
• Non-absorbable sutures or wound clips should be removed from 7-14 days post-operatively. If not removed, the remaining suture material or clips can act as a foreign body and lead to skin infections.