ADVANTAGES OF OVARIECTOMY OVER OVARIOHYSTERECTOMY
The midline incision for an ovariectomy is typically short and focused on the ovaries, while an ovariohysterectomy incision
is usually a compromise attempting to provide exposure to the entire length of the internal reproductive tract. A shorter
incision may reduce the chance of dehiscence and other wound complications. And since ovariectomy is limited to the ovarian
region, the chances of damaging ureters distally near the uterine body should be nonexistent.1 Ovariectomy should not pose the risk of vesicovaginal or ureterovaginal fistula, which has been associated with ovariohysterectomy.26,27
Although an ovariectomy should be faster to perform than an ovariohysterectomy in the hands of an experienced surgeon, that
was not found in one study.28 However, this study used an ovariohysterectomy technique in which electrosurgery was used and the broad ligaments were not
ligated, which may have increased the time efficiency of the ovariohysterectomy since there would only be three major ligations
as opposed to four major ligations in the ovariectomy.
In the procedures detailed earlier, ligation and transection through the tip of the uterine horn caudal to the proper ligament
were described. Some authors specify that ligation and transection should be located through the proper ligament and not through
the uterine tip.16,25 By not entering the lumen of the uterus, the possibility of vaginal bleeding is eliminated.1 It has similarly been claimed that ovariectomy through the proper ligament precludes stump granulomas.1 However, the proper ligament is quite short, and, especially in bitches, the mesosalpinx, mesovarium, and broad ligament
may contain substantial fat that renders it difficult to ligate and transect accurately through the proper ligament while
avoiding the fat-obscured ovary. Nevertheless, stump granulomas at the uterine horn tip in ovariectomies have not been described.1
Stump pyometras cannot occur in an ovariectomized animal.1 However, an ovarian remnant in an ovariectomized animal could result in pyometra.
In dogs with mammary cancer, a midline or flank ovariectomy may be preferred over an ovariohysterectomy because of its smaller
incision, which is less likely to complicate concurrent mammary lump excisions. Cats with mammary hyperplasia may be treated
by ovariectomy through a flank incision to minimize the risk of hemorrhage that would be incurred by a midline approach.
Since an ovariectomy is less invasive1,19 and requires less excision and ligation of tissues than an ovariohysterectomy does, it may result in less incision complications
and pain. However, that was not found experimentally in one prospective study.28
Ovariectomy and ovariohysterectomy are equally effective in preventing reproduction and reducing the risk of mammary cancer.
Ovariectomy and ovariohysterectomy share many of the same indications, but ovariectomy may be simpler and quicker to perform.
And the less invasive procedure may result in less discomfort and less likelihood of complications. As a result, in young
animals with normal uteri, ovariectomy may be preferred over ovariohysterectomy. With experience, veterinarians should encounter
little difficulty in adopting a form of this procedure.
Eric E. Ehrhardt, DVM, MS
Fruit Valley Veterinary Clinic
7100 State Route 104
Oswego, NY 13126