Surgery and Other Experimental Procedures

Any person participating in a research activity involving vertebrate animals must be listed in the approved protocol, and must be qualified to perform the intended procedures on that particular species. In some instances investigators may be required to provide proof of proficiency or credentials to perform a particular procedure or work with a particular animal species. Experience and training may be obtained from the Principal Investigator (PI), through the veterinarian, or from relevant outside training opportunities.

Classification of surgery and other experimental procedures

The following list of definitions has been prepared to clarify categories and requirements for using animals in surgical and non-surgical procedures. This list is meant to serve as a guideline for research staff in the proper handling of animals in IACUC-approved facilities and in IACUC-approved research activities.

Surgery

Usually involves an incision and exposure of a tissue for an operative method or the operative manipulation of physiological or physical parameters to create a model of a clinical disease process or condition and/or treatment of a disease or condition. Surgery usually requires anesthesia, and is further subclassified as major or minor, and survival or non-survival (see below).

Procedure

Any manipulation of an animal for an experimental application, for examination purposes or for treatment of an induced or spontaneous disease or condition.

For clarity of definition, surgical procedures will be considered under the classification of Surgery while Procedures will include:

  • injection
  • bandaging or casting
  • imaging
  • antibody production
  • collection of blood and other clinical samples
  • non-invasive physiological monitoring
  • euthanasia, etc.

Procedures may or may not require the use of a sedative or anesthetic, and may or may not require the use of analgesics.

Survival surgery

Animal regains consciousness, for any period of time, after anesthesia.

Non-survival surgery (acute surgery, terminal surgery)

Euthanasia is performed while the animal is under general anesthesia. The animal never awakens or regains consciousness.

Major surgery

Any surgical intervention that penetrates a body cavity (i.e. cranial, thoracic, abdominal, pelvic, ocular or orbital, skeletal, joint), or has the potential for producing a permanent impairment of a physical or physiological function.

Examples of major surgery include:

  • Surgical access of a body cavity (see above)
  • Injury or repair of a tendon or ligament
  • Bisection (partial or complete) of muscle or tendon
  • Amputation of a limb
  • Nephrectomy or nephrotomy
  • Enucleation
  • Open surgical biopsy of a major organ
  • Surgical implantation of indwelling medical or monitoring devices
  • Orthopedic procedures involving a surgical approach
  • Neutering of male animals

Minor surgery

Any surgical intervention that does not penetrate a body cavity or that does not ordinarily have the potential to result in impairment of a vital physical or physiological function.

Examples of minor surgery include:

  • Percutaneous or cut-down approach to a superficial artery or vein for catheterization or other purposes
  • Tissue biopsy not involving surgical exposure of a body cavity
  • Skin and subcutaneous implants
  • Removal of small digits or tail amputation in small animals
  • Endoscopy, colonoscopy, tracheoscopy, and laparoscopy (in which only a small penetrating incision is made in the skin)
  • Surgical repair of a superficial injury

Large animal: Animal species that are taxonomically defined as lagomorphs or higher (e.g., rabbit, cat, dog, ferret, sheep, goat, swine, non-human primate).

Rodent: Animal species that include mice, rats, guinea pigs, hamsters, gerbils.

Non-animal: Vertebrate animals that are not classified as mammals. For regulatory purposes, non-mammals are considered different than mammals for requirements involving surgical and non-surgical procedures. Animals included in this category are fish, amphibians, reptiles, and birds.

Aseptic technique: A technique used for surgery or other procedures that is designed to maintain an object or anatomic area in a condition as free as possible from all microorganisms and infection. It is used whenever body tissues must be penetrated and the animal is intended to recover from anesthesia. It is designed to protect the animal as well as the person performing the procedure and may require the use of a dedicated room or area. Aseptic technique is further defined below as strict or modified, depending on the type of procedure performed and the animal classification.

Strict aseptic technique: This includes:

  • a dedicated, clean, and uncluttered work area
  • a pre-sanitized work area
  • the pre-surgical or pre-procedural preparation of skin surfaces (i.e., hair clipped, skin shaved if applicable, disinfectant soap scrub)
  • the surgery/procedure preparation of the skin site (iodophor and/or alcohol scrub)
  • the sterile draping of the surgery/procedure skin site
  • the use of sterile instruments and supplies
  • surgeons prep (i.e., removal of jewelry from hands and wrists; 5 minutes of thorough scrubbing of fingers to elbows using iodophor or surgical disinfectant
  • wearing of surgical clothing (i.e., scrub suit, cap, mask, shoe covers, sterile gown, sterile gloves)

Modified aseptic technique: This technique may, depending on the type of surgery or procedure and classification of animal, waive some of the requirements of the strict aseptic technique defined above. Modifications may involve waiving the need for a dedicated work area, requirement for sterile instruments and supplies, wearing of surgical clothing, pre-surgery or pre-procedure preparation of the animal subject or surgeon, and sterile draping of the surgery/procedure site.

Animal surgery and procedure areas

Procedure area: Routine procedures in large animals must be performed in designated procedure/treatment rooms. Non-survival procedures, including euthanasia, must not be performed in animal housing rooms. Routine survival procedures on small animals should be performed in either designated hoods in animal housing rooms, in dedicated procedure rooms in animal facilities, or in other IACUC-approved satellite locations (e.g., irradiators, imaging suites). If satellite locations are involved, rodents should be returned to specified holding rooms instead of their original housing rooms in order to prevent spread of infectious agents potentially encountered while outside the vivarium. Non-survival procedures on small animals (mice, rats, hamsters and guinea pigs) including euthanasia, should not be performed in animal housing rooms except as required in BL-2 rooms or rooms under quarantine, but may be performed either in dedicated procedure rooms in animal facilities or in other IACUC-approved locations (e.g., specific laboratories, imaging suites).

The location in which the procedure is to be performed must be specifically identified in the protocol. When procedures cannot be performed in a designated animal treatment/procedure room within an animal facility, the following are required: (1) the procedure must be performed in an area separate from other activities (a separate room is not required); (2) the activity in the area must be limited to the procedure conducted; (3) the area must be kept neat and uncluttered, and easily cleaned and sanitized; (4) personnel access to the area must be limited; (5) modified aseptic technique must be used.

Surgery area: The surgery area requirements are determined by animal classification and type of surgery, as follows:

Major survival surgery, large animal

Operations must be performed in a dedicated surgery facility using strict aseptic technique. 

IACUC-approved surgery facilities comprise:

  • surgical support areas
  • animal preparation areas
  • surgeon preparation areas
  • surgical supply areas
  • operating room(s)
  • post-operative recovery/care animal areas

Minor survival surgery, large animal

Operations do not require the use of dedicated surgery facilities, but strict aseptic technique must be followed. 

The surgery area requirements are:

  • a separate, easily sanitized, and uncluttered area (a separate room is not required)
  • the activity in the area must be limited to the procedure conducted
  • access to the room must be limited

Non-survival surgery, large animal

Operations do not require the use of dedicated surgery facilities, and modified aseptic technique must be followed: sterile supplies are optional, drapes are required, and instruments must be clean and sanitized.

Other surgery area requirements as described for minor survival surgery large animal are to be followed:

  • a separate, easily sanitized, and uncluttered area (a separate room is not required)
  • the activity in the area must be limited to the procedure conducted
  • access to the room must be limited

Survival surgery, rodents and non-animal

Operations do not require the use of dedicated surgery facilities, and modified aseptic technique must be followed:

  • sterile supplies must be used
  • dedicated laboratory clothing (e.g., lab coat, surgery scrubs, clean surgical gown) must be worn sterile clothing optional
  • a sterile field must be maintained
  • sterile drapes are optional but recommended
  • face mask and sterile gloves must be worn

Other surgery area requirements described for minor survival surgery large animals are to be followed:

  • a separate, easily sanitized, and uncluttered area (a separate room is not required)
  • the activity in the area must be limited to the procedure conducted
  • access to the room must be limited

Non-survival surgery, rodents and non-animal

Operations do not require the use of dedicated surgery facilities, and modified aseptic technique must be followed: sterile supplies are optional, dedicated laboratory clothing must be worn, and drapes are optional but recommended.

Other surgery area requirements as described for survival surgery rodents are to be followed:

  • a separate, easily sanitized, and uncluttered area (a separate room is not required)
  • the activity in the area must be limited to the procedure conducted
  • access to the room must be limited

Animal surgery records

  • Adequate and appropriate records of pre-operative/intra-operative/post-operative care must be maintained for all animals used in protocols involving surgical procedures.
  • Provision of pre-operative/intra-operative/post-operative animal care is the responsibility of the PI.
  • The veterinarian is responsible for monitoring post-operative care to ensure proper procedures and practices are followed to minimize pain and distress, and also to ensure that only procedures approved in the protocol are employed.
  • Animal care staff may provide emergency veterinary care when the Attending Veterinarian or his or her designee determines that immediate intervention is needed to save the life of the animal or relieve pain, and neither the PI nor his or her research staff members are available or cannot be contacted within a reasonable time (determined by the nature of the veterinary emergency).

For all survival surgery, large animal operations, the following records must be maintained by the PI or his or her designee in the animal facility in which that animal is housed:

  • animal history and IACUC protocol number
  • anesthesia records and intra-operative monitoring notes
  • surgery notes, clinical laboratory data
  • radiographs and other clinical imaging information
  • histopathology (biopsy) reports
  • daily observations and post-operative progress notes

For all non-survival surgery, large animal operations, the following records must be maintained by the PI or his or her designee in the animals individual health record:

  • animal history and IACUC protocol number
  • anesthesia records and intra-operative monitoring notes
  • surgery notes, intra-operative clinical laboratory data
  • radiographs and other clinical imaging information
  • necropsy and histopathology reports
  • The individual health record will be maintained by the animal care staff

For all survival and non-survival surgery, rodent and non-animal operations, the following records will be maintained by the PI or his or her designee on the cage card affixed to the animals cage or tank:

  • IACUC protocol number
  • date of surgery
  • name of operation performed
  • other records as listed above for large animals
  • These records may be maintained in the PI staffs offices or laboratories but must be easily accessible to the veterinarian and IACUC staff