Share thisRodent surgeries are commonly performed within the biomedical field since rodents comprise over 90% of animals used in research. These surgeries range from basic procedures such as osmotic pump implantation to complex procedures such as gastric bypass. The frequency of rodent surgery has been growing steadily since the development of the transgenic mouse. There are certain factors that determine the success of rodent surgeries.1-5
Facilities
The area chosen for rodent surgery must be clean as well as clear of clutter and unnecessary equipment prior to surgery. The surfaces must be easily sanitizable, and the procedures must be conducted in a low traffic area that is not used for other activities during the time of surgery. All of these aspects decrease the potential for surgical contamination.1-3The surgical area should be large enough to allow enough space for the animal, surgical instruments, and any other items that might be required during the surgical procedure, and should not restrict the surgeon’s movements. This decreases the chance of contamination from inadvertently bumping into non-sterile items. A cramped area makes it difficult to maintain the suture sterile. In our experience, because of its length, the suture tends to be one of the items to become more readily contaminated during surgery, as it can easily fall outside of the sterile area.
Magnification and Illumination
Good visualization during rodent surgery by incorporation of magnification plays an integral part in the outcome of the surgery, however there is little consensus regarding its implementation. Most rodent surgeries are performed without the use of magnification. Once surgeons begin to use magnification and become comfortable using it, they often conclude that working without the benefit of magnification is inadequate. The advent of microscopy in rodent surgery has increased options for surgeons and has significantly improved the quality of surgery. A single-binocular scope is fine for a single working surgeon. Dual-head stereo microscopes with 10X or 12X magnification, either on a floor-stand or table-top (Carl Zeiss, Leica, Nikon) are ideal for the occasion where more than one surgeon is involved. Attaching cameras to the microscopes will allow for the production of training videos or the collection of images for research or teaching purposes. Performing surgical procedures under a microscope gives the surgeon the ability to assess finite details of the procedure which will decrease the amount of mistakes secondary to poor visualization. Lessening intra-operative mistakes can make procedures more cost effective. While there can be a substantial learning curve and upfront cost associated with utilization of a microscope during surgical procedures, the long term benefits associated with improved surgical outcome and increased animal welfare make the investment worthwhile.
Illumination is just as important as magnification. Many rodent surgeons who perform procedures such as jugular or carotid catheterizations perform them without the assistance of additional illumination. When a light source is utilized, it is commonly an incandescent light such as a desk lamp. Utilization of a light source improves visibility and decreases eye strain which can lead to fatigue and poor surgical outcomes—especially when a surgeon performs several surgeries in a row. A cold light source such as halogen or xenon is preferred since other light sources emit significantly more heat, which can desiccate tissues and even cause thermal tissue damage. Fiber optic illuminators equipped with a dual goose neck are particularly useful as they allow the surgeon needed flexibility in directing the light to exact locations. The utilization of appropriate magnification and lighting during rodent surgery enhances visual acuity, which in turn increases the chance of a successful outcome.