One alternative technique for ovariectomy omits the forceps and leaves behind some tissue (albeit with a ligated vascular supply) between the ovarian pedicle and the uterus. After the ovarian pedicle and the tip of the uterus are ligated, the ovary and associated structures are kept exteriorized by hemostatic forceps placed through the fenestration of the mesovarium and clamped to the drape (Figure 1). The mesosalpinx-enclosed ovary is grasped with tissue forceps. Then scissors (or a scalpel) are used to transect the tissues from cranial to the uterine tip ligature to distal to the ovarian pedicle ligature in an arc (dotted line) about 0.5 cm from the ovary, and the ovary is removed.^1,2

Figure 1

Another common variant in dogs involves excising the mesosalpinx. The abundant canine periovarian adipose tissue has been suggested as a contributing factor to ovarian remnants in spayed bitches.³ To ensure that the ovary is positively identified and completely removed, the bulky fat-filled mesosalpinx is excised before the ovary is excised. Scissors are inserted into the slitlike entrance of the ovarian bursa located on the medial surface, and then the mesosalpinx is lifted from the ovary and stretched by opening the scissors. The mesosalpinx is then grasped free of the ovary and incised with scissors. Any portions of the mesosalpinx and associated uterine tube and infundibulum that cover the ovary are excised with scissors (Figure 2).

Figure 2

With the mesosalpinx completely removed, the now visible ovary is excised with scissors. Tissue adjacent to the exposed ovary is grasped with tissue forceps, and scissors are used to transect the tissues from cranial to the uterine tip ligature to distal to the ovarian pedicle ligature in an arc about 0.5 to 1 cm away from the ovary (Figure 3).⁴ This technique also leaves behind some tissue between the ovarian pedicle and the uterus. A possible drawback is that direct handling of a friable ovary may allow detachment and reimplantation of an ovarian tissue fragment.⁵

Figure 3

Ovariectomy without salpingectomy
As previously noted, in mature—especially obese—dogs, the ovary is hidden by large amounts of adipose tissue within the mesosalpinx. Some surgeons recommend, after placing the aforementioned ligatures, opening the ovarian bursa with scissors and then directly grasping the ovary with tissue forceps. The ovary is excised with scissors along its longitudinal ridge of attachment while leaving the mesosalpinx in situ.⁶ This sequence allows positive identification of the ovary coupled with efficient excision.

REFERENCES
1. Brass W. Ovar und uterus. In: Schebitz H, Brass W, eds. Operationen an hund und katze. Berlin, Germany:Parey, 2007;273-274.
2. Berge E, Westhues M. Tierärztliche operationslehre. Berlin, Germany:Parey, 1969;340-342.
3. Ball RL, Birchard SJ, May LR, et al. Ovarian remnant syndrome in dogs and cats: 21 cases (2000-2007). J Am Vet Med Assoc 2010;236:548-553.
5. DeNardo GA, Becker K, Brown NO, et al. Ovarian remnant syndrome: revascularization of free-floating ovarian tissue in the feline abdominal cavity. J Am Anim Hosp Assoc 2001;37:290-296.
6. Ibacache MPF. Evaluación de dos técnicas de abordaje quirúrgico utilizadas en la esterilización de hembras caninas (Evaluation of two surgical techniques used in sterilization of female dogs). Dissertation. Universidad Austral de Chile, 1997.