Principles of Rodent Surgery for the New Surgeon

The overall goal of this procedure is to outline the principles and practices involved in aseptic surgery in rodents. This is achieved by first introducing the concept of the sterile field. Next, the correct preparation of the work area that will allow for a smooth workflow and maintenance of the sterile field is demonstrated.

Then the steps necessary to prepare the animal and surgeon that will minimize the introduction of environmental contaminants and pain to the rodent are described. Finally, simple surgical considerations such as tissue handling and postoperative care of the surgical subject are discussed. Generally, researchers new to surgery will struggle because they're learning both aseptic technique and a technically demanding surgical procedure at the same time.

Visual demonstration of aseptic technique is important because often these skills are new to individuals that have no formal medical training. Before beginning any surgical procedure, it must be approved by the local legal or ethical authority. This might include an institutional animal care and use committee, an ethics committee, or the home office.

This video is meant to be an introduction or supplement to hands-on training that that is provided at your institution. The goal of surgical procedures on rodents is a sepsis or the lack of infection following surgery. To achieve this, the surgeon's hands must be disinfected, the instruments sterilized and the surgical area sanitized.

Even with excellent aseptic technique, bacteria originating from the patient may still be introduced into a wound. Proper aseptic technique limits the risk of introduction of infectious agents, primarily bacteria into wounds and surgical sites. The sterile field encompasses the area where the instruments are laid out and the area prepared on the animal for surgery.

A sterile field is the area above, below and surrounding the animal that contains the front of the surgeon and all the supplies and equipment necessary for the surgery. If equipment, materials, or the surgeon move outside the sterile field, the surgeon must stop and address the break of technique immediately to avoid the risk of infection. Rodent surgeries do not require dedicated surgical suites, but ideally are conducted in a hood or lamina flow cabinet.

The area should be tidy, well lit, and out of traffic flow. If the surgeries to be conducted on a laboratory bench top, it should be well cleaned with a disinfectant. Prior to setting up the surgical area, arrange the surgical area so that there are three distinct zones.

Preparation, surgery, and recovery for the preparation area, assemble the supplies needed such as lubricating, ophthalmic ointment, clippers, or eraser, and surgical scrub solutions for the surgical area, assemble and arrange the needed supplies, such as a recirculating water heating pad for keeping the rodent warm and a sterile waterproof pad. If successive surgeries are to be performed in a session, an instrument sterilizer such as a hot bead sterilizer should also be available. Finally, assemble the materials required to close the surgical incision, suture and needles, staple applicator staples or tissue glue.

Any other equipment necessary such as stereotaxic apparatus, implants, or an operating microscope should also be arranged. The recovery area should contain a large cage placed on a heating pad, which should typically be lined with flat paper bedding at the start of surgery. All instruments should be clean and sterile.

This is often accomplished by creating complete surgical packs that are autoclave.Stereotaxic. Instruments should be cleaned well between surgeries and parts, contacting animals such as the ear or incisor bars, or used by the surgeon, like the knobs should be disinfected before use and between animals. Knobs can be covered with sterile wrap to ensure sterility during surgery.

Instruments may be used for more than one rodent surgery without autoclaving and repacking, but should be cleaned and sterilized between rodents, such as with a hot bead. Sterilizer allow time for the instruments to cool down after sterilization before they contact tissue. Again, instruments may be called by dipping In sterile water, alcohol is not a sterrett.

Three types of drugs are typically administered to rodents prior to surgery, anesthesia, analgesics, and antibiotics. Anesthesia can be administered as an inhalant or injected. The most common inhalant anesthetic in use in rodents is isof fluorine.

Common injectable anesthetics include ketamine and xylazine with or without another sedative added. Many anesthetics abolish the blink reflex. Always use sterile ophthalmic ointment to protect the eyes before beginning any procedure.

Preemptive analgesics are recommended and include nonsteroidal anti-inflammatories such as flu nixon and and opioids such as buprenorphine or morphine. To prep the surgical area, first shave the hair. Hair can carry contamination into the surgical incision, so shave an area larger than the anticipated incision with wide margins.

For example, for a one centimeter incision, a three centimeter area is often prepared. This may be limited by the size of the animal or anatomical region. Perform three alternating applications of a surgical scrub and 70%ISA profile alcohol either in a circular pattern or unidirectional end with a final application of scrub solution, not alcohol.

Next, position the animal so that the surgical site is upwards facing The surgeon finally perform a toe pinch to verify that the animal is deeply anesthetized. Preparation of the surgeon should emphasize that a special activity will be taking place, one in which the surgeon must be cognizant of their every move in and out of the sterile field. The hair and face are generally covered by a cap and mask respectively.

These should be new at the start of the surgical session, but do not need to be changed between animals. Hands should be cleaned well before surgery. Sterile surgical gloves should be used for surgery.

Gloves should be changed between animals or if damaged or contaminated during a procedure. Ideally, surgeons should wear a disposable surgical gown, but a clean lab coat either disposable or recently laundered is acceptable. The lab coat does not need to be changed between animals, but should be changed between surgery sessions.

To begin surgery, drape with a sterile waterproof drape. Periodically monitor animals for proper oxygenation and anesthetic depth. If monitoring anesthetic depth involves a break in sterility, then a surgical assistant should perform this task.

Breaks in sterility should be corrected immediately. Common breaks in procedures include scratching your face or touching items outside the sterile field like a light source, gloves should be changed immediately if there is a lapse in sterility. Additional support for the animal should include intraperitoneal, subcutaneous, or intravenous administration of warm, sterile, physiologically balanced solutions, such as 0.9%Sodium chloride recover animals in warm cages bedded with paper towels or some other flat paper bedding, not standard animal husbandry bedding.

The recovery cage can be placed half on a heating pad, allowing the animal to move to a cooler area once it is mobile return. Post-surgical animals to animal holding only after they can move normally about the cage after surgery. Make food and water easier to access.

Water is added to the food to soften it so that animals may find it easier to eat. Animals should be monitored for signs of pain and may require postoperative analgesia. Also, monitor surgical wounds for inflammation or infection.

Wound closures should be removed 10 to 14 days after surgery. A successful surgery is one where there is no infection. Pain is minimal, and the goal of the researcher in performing the surgery is met.

Specific surgeries and their aims will differ from laboratory to laboratory, but aseptic technique is always indicated. Surgeries and learn skill. The more surgeries you perform, the greater your confidence and success will be in maintaining aseptic technique.

After watching this video, you should have an idea of how the principles of aseptic technique apply to rodent surgery. Every surgery will have its own specific technical needs, but the principles of asepsis always apply.