Efficient spay/neuter techniques (Proceedings)

Think back to when you first learned to perform ovariohysterectomies and neuters. It is probable that you were taught these procedures early in your surgical education at a time when you had limited surgical skills. Your instructors, therefore, taught very cautious techniques: double ligating everything, ligating pedicles before you transect, extensive exposure and many other techniques, to compensate for your lack of skill and experience. Often as people get more experience in surgery their efficiency improves, but there is a tendency to continue to use the techniques they were originally taught; techniques that were designed to compensate for lack of experience. The techniques used in high volume spay neuter clinics are safe and much more efficient that many of the techniques commonly taught in veterinary schools.

Helpful hints

When prepping the patient for surgery, clip the hair, vacuum, and then use a lint roller to remove any remaining hair. While this procedure will not significantly improve efficiency it will almost totally eliminate the frustration of chasing loose hairs out of your surgical field.

Where does the surgeon stand?

How do you decide where you stand while doing a spay? Do you stand with the patient's head to your right or to your left? Most right-handed veterinarians stand with the patient's head to their left and most left-handed veterinarians stand with the patient's head to their right. But why is this? Try standing with the patient's head to the side of your dominant hand. There is a very valid reason for this. If you strum the suspensory ligament of the ovary this allows you to strum it with your stronger hand. If you cut the suspensory ligament it allows you to cut the ligament easily with your dominant hand.

Positioning of the patient

In a spay, position the patient with the front legs along it's side rather than pulled forward past it's head. Pulling the legs forward, which is most commonly done, tightens the muscles of the back and tightens the suspensory ligaments of the ovaries. Pulling the limbs along side the patient's thorax will relax the suspensory ligaments and make delivery of the ovaries through an abdominal incision easier. A simple restraint devise allows this positioning of the patient and helps prevent tilting of the patient to one side or the other.

Placement of the incision

One of the keys to efficient surgeries is making a small incision. While most surgery instructors promote long incisions and maximum exposure, lengthy incisions are more time consuming to close. Small incisions, obviously, can be closed more rapidly than long incisions. The proper location of the incision varies with species and with age of the patient. In a cat spay the tissue that is most difficult to exteriorize is the uterine body. In the adult dog it is more difficult to exteriorize the ovaries. Puppies are intermediate. In the cat spay the skin incision should be located on the ventral abdominal midline at the exact midpoint between the umbilicus and the anterior brim of the pubis. In the adult dog, the skin incision is on the ventral abdominal midline in the cranial third of the distance between the umbilicus and the anterior brim of the pubis. In the puppy spay (6 months or younger) the skin incision is on the ventral abdominal midline a little cranial to the location of the cat spay incision and a little caudal to the location of the incision in an adult dog.

Let's look, again, at the adult dog spay. In the adult dog it is most difficult to exteriorize the ovaries. The right kidney and the right ovary are located further cranial in the abdomen than the left kidney and left ovary. It is, therefore, more difficult to exterior the right ovary than the left ovary. To equalize the difficulty of exteriorizing the two ovaries make the entry into the abdomen through a right paramedian incision. You incise the skin on the midline, undermine only on the right side of the linea alba and, depending on the size of the dog, incise the rectus sheath 1 to 2 cm to the right of the linea alba. It is important to only incise the fascia. Avoid incising rectus abdominis m. to prevent hemorrhage. Entry into the abdomen is then accomplished by bluntly separating fibers of the rectus abdominis muscle and cutting the peritoneum.

Castration incisions in the cat, the puppy and in the adult dog can be made through the scrotum.

Ligation techniques

Most of you were probably taught to double ligate ovarian pedicles and uterine stumps and to ligate before transecting the tissue. Both of these techniques slow you down in surgery. It is much more efficient to single ligate and to transect the ovarian pedicles and uterine body prior to ligation. The most efficient technique is to place 3 hemostats, the first proximal, the second several millimeters distal to the first, but still proximal to the ovary and the third between the ovary and the uterine horn. Close the first hemostat one click, the second two clicks and the third three clinics. The purpose of the 1, 2, 3 clicks is to avoid crushing the ovarian pedicle which would predispose the pedicle to tearing. Before ligating, transect the ovarian pedicle just distal to the second hemostat. Ligate with either a square or surgeon's knot with a hand tie.

Hand ties

Becoming skilled at hand ties, both square knot and surgeon's knot, will improve efficiency in both dog and cat spays. To be efficient this skill must be practiced. But once you are skilled at hand ties it increases your speed significantly.

Pedicle tie/cord tie/figure eight knots

These are methods of ligation in which the structure is tied to itself around a hemostat. They can be used in cat castrations, puppy castrations and in legating the ovarian pedicles in cat spays.

Millers knot

The Miller's knot is a very secure, self-locking knot that can be placed either with an instrument or with a hand tie. It allows single ligation in many canine castrations. Some surgeons also use the Miller's knot on ovarian pedicles in dogs.

Pediatric techniques

While each of the techniques described above will improve efficiency of surgery, perhaps, the greatest impact on efficiency is by patient selection. Put simply spaying a two to five month old cat is much quicker than spaying an adult cat. Spaying or castrating a two to five month old dog is much quicker than spaying an adult dog. The patients are smaller, there is less risk of hemorrhage, and the incisions are smaller. (Pediatric techniques will be presented in another paper).

Each of these techniques will reduce the time it takes to perform the surgeries. When combined they can result in significant reduction in surgical time.

These techniques will be demonstrated through movies of each of the surgical procedures, cat spay, cat castration, puppy spay, puppy castration, dog spay, and dog castration.