Institutional Animal Care and Use Committee
Southern Illinois University
Subject:
Mammalian Animal Surgery
Purpose:
To ensure surgical procedures are performed appropriately and in accordance with
applicable regulations and guidelines.
Guidelines:
Surgical procedures can be classified as survival vs. non-survival, and major vs. minor. In survival surgery,
animals recover from anesthesia following the procedure, while in non-survival procedures the animals are
euthanatized before recovery from anesthesia. Major surgical procedures penetrate or expose a body
cavity, or have the potential to produce substantial impairment of physical or physiologic functions. Minor
survival procedures do not expose a body cavity and cause little or no physical impairment.
Multiple major survival surgical procedures on a single animal are discouraged but, may be considered for
approval by providing appropriate scientific justification on the Animal Care and Use Protocol form. The
justification should describe why multiple major survival surgical procedures on a single animal are
necessary to meet the scientific objectives of the study. Cost savings alone is not an adequate reason for
performing multiple major survival surgical procedures in a individual animal. Multiple major survival surgical
procedures also must not be performed on any animal as part of different proposals. Animals that undergo
emergency major operative procedures as part of veterinary care, however, may still be used in a proposal
that requires a major survival operative procedure. Animals surviving a major operative procedure must be
identified to prevent their use in a second major survival operative procedure.
All surgical procedures performed on animals should be performed by or under the supervision of an
appropriately trained individual with experience in the respective technique(s). It is the responsibility of the
Principal Investigator to ensure that appropriate training has been provided. When possible, newly received
animals should be acclimated to their pre and post surgical housing for 5 days before performing surgery.
All rodent surgeries must be performed in areas, such as laboratories, that are able to be sanitized and are
free of unnecessary items. During surgeries, activities unrelated to the surgical procedure are discouraged
in the vicinity of the operative procedure to minimize the occurrence of aerosol contamination of the surgical
site.
In general, mammalian, non-rodent surgeries should be conducted only in surgical facilities dedicated to that
purpose and should be operated and maintained under aseptic conditions unless an exception is specifically
justified as an essential component of the research protocol and approved by the IACUC. Operative
procedures conducted at field sites need not be performed in dedicated facilities, but must be performed
using aseptic procedures whenever possible. Emergency situations may require immediate surgical
intervention under less than ideal conditions when movement to a surgical facility poses an unacceptable risk
to the animal or is impractical. When such situations arise, every effort should be made to perform the
procedure in as sanitary and aseptic a manner as is reasonably possible.
The functional components of a dedicated surgery suite include areas for surgical support, animal
preparation, surgeon's scrub, operating room (OR), and postoperative recovery. The non-surgical support
areas should be separated from the operating room by physical barriers. The interior surfaces should be
constructed of materials that are monolithic and impervious to moisture. Ventilation systems should provide
positive pressure in the operating room relative to adjacent areas. Surgical facilities should be maintained
and operated in a manner that ensures cleanliness and minimizes unnecessary traffic. In circumstances
where it is necessary to use an operating room for other purposes, it is imperative that the room be returned
to an appropriate level of cleanliness before its use for aseptic surgery.
Date of IACUC Approval: May 28, 2003
Pre-operative fasting for 6 - 12 hours may be necessary in some species to decrease the risk of aspiration
during anesthesia or to help evacuate the gastrointestinal tract prior to its surgical manipulation. For survival
surgical procedures of all species, the hair or fur should be removed from the surgical site, followed by
disinfection of the skin. Attempts should be made to maintain the animal's normal body temperature by
minimizing heat loss and/or providing supplemental heat as is appropriate for the given species. Smaller
species are particularly prone to hypothermia due to their large surface area to body mass ratio, allowing a
greater loss of body heat. The animal's eyes should be protected against corneal drying and ulceration.
If non-survival surgery is performed, the instruments and supplies must be clean, but do not have to be
sterile. If survival surgery is performed, all instruments and supplies having contact with the surgical site or
sterile field must be sterile.
For survival surgery in non-rodent species, a single set of sterilized instruments should only be used on one
animal before re-sterilizing. Provided the instruments are handled appropriately and have not contacted nonsterile surfaces, a single set of sterilized instruments may be used on up to 5 animals before the instruments
must be re-sterilized when performing serial rodent surgeries.
When non-survival surgery is being performed on any animal, the surgeon must wear gloves, but the gloves
do not have to be sterile. If survival surgery is being performed on rodents, the surgeon should wear sterile
gloves. If a survival surgery is performed on a non-rodent species, the surgeon must wear a scrub suit,
facemask and/or facial hair covering, hair covering, sterile gown, and sterile gloves.
During survival surgeries, aseptic techniques should be used to reduce the microbial contamination to the
lowest possible practical level. Antibiotics should not be considered as a replacement for aseptic procedures
and are not recommended to be given routinely following surgery. However, if a nonsterile part of an animal,
such as the gastrointestinal tract, is to be surgically exposed or if a procedure is likely to cause
immunosuppression, pre and post-operative antibiotics may be appropriate. The surgical site should be
closed in a manner acceptable by general veterinary standards. Silk or other braided suture material should
not be used when closing skin incisions due to the potential for wicking bacteria contaminated moisture into
the surgical site. Surgical or other painful procedures should not be performed on unanesthethized animals
paralyzed by chemical agents.
It is the responsibility of the investigative staff to monitor the animals during the anesthetic recovery period
and each day during the post-operative clinical recovery period, including weekends and holidays. Animals
should be recovered from anesthesia in a clean, dry, warm environment where they can be frequently
observed by trained personnel, and separated from other animals not recovering from anesthesia . During
anesthetic recovery, particular attention should be given to thermoregulation, cardiovascular and respiratory
function, and postoperative pain or discomfort. If the anesthetic recovery period is prolonged, it may be
necessary to rotate the animal approximately every 30 minutes from lateral recumbency on one side to
lateral recumbency on the other side to avoid hypostatic congestion of the lungs. Animals can be returned to
their cages/pens after they are able to ambulate relatively normally.
After anesthetic recovery, during the post-operative clinical recovery period, the necessary intensity of
monitoring will vary with the species and the procedure performed. During this period, the animals should be
assessed for signs of pain or discomfort and general well being, and the surgical site monitored for normal
healing progression and signs of post-surgical infection. Supportive care should be provided as needed. If
the procedures produce or are expected to produce more than momentary or slight pain or distress to the
animals, appropriate sedation, analgesia, or anesthesia should be administered unless it is described, in
writing by the principal investigator, to be contrary to the goals of the study for scientific reasons. Monitoring
and supportive care normally continues for 7 to 10 days or until the skin sutures or staples are removed.
Maintenance of records describing surgical procedures, anesthetic monitoring, post-operative observations
and treatments are recommended.
Date of IACUC Approval: May 28, 2003