How to perform a two-portal laparoscopic ovariectomy - Veterinary Medicine
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How to perform a two-portal laparoscopic ovariectomy
Learn more about this laparoscopic procedure, which produces less pain and tissue trauma than a routine open ovariohysterectomy does. Then consider whether you should take the necessary steps to offer it in your practice.


VETERINARY MEDICINE


Many reasons exist for performing ovariectomies instead of ovariohysterectomies in healthy bitches. Compared with ovariectomy, ovariohysterectomy in dogs is technically more complicated and time-consuming and is likely associated with greater morbidity (larger incision, more intraoperative trauma, increased discomfort).1 No significant differences between the two procedures have been observed for the incidence of long-term urogenital problems, including endometritis, pyometra, and urinary incontinence.1 In addition, there is no benefit and, thus, no indication for removing the uterus during routine neutering in healthy bitches.1


Figure 1
Further, a recent study concluded that laparoscopic-assisted ovariohysterectomies caused less surgical stress and up to 65% less postoperative pain than a traditional open surgical spay.2 Thus, I believe that performing ovariectomies laparoscopically further reduces the incision size, tissue trauma, and overall level of pain experienced by the patient compared with performing an open ovariectomy or open ovariohysterectomy. And because of video magnification of the laparoscopic image, some surgeons think it is easier to visualize the ovary during laparoscopy than during an open procedure, helping to ensure complete removal of the ovarian tissue.3


Figure 2
I encourage all veterinarians interested in incorporating laparoscopy into their practices to take basic and advanced courses offered by The University of Georgia, Colorado State University, and elsewhere before applying this technique. I hope that my describing this technique in detail will help facilitate its acceptance and use in practice and its further refinement. I also hope my experience with the technique will help veterinarians avoid certain pitfalls that I have learned the hard way.

EQUIPMENT NEEDED

The equipment and instruments required to perform laparoscopic ovariectomy in dogs and cats are listed below. All personnel involved in performing laparoscopic surgery will need appropriate training in the procedure as well as in cleaning, disinfecting, sterilizing, and maintaining the instruments and equipment.

  • A laparoscope and cannulas/cannula-trocar assemblies. In my practice, I use a 5-mm-diameter, 0- or 30-degree field-of-view rigid endoscope with a working length of 28 to 33 cm with the threaded Ternamian EndoTIP (Karl Storz) 6-mm cannula for the primary camera/caudal portal in all dogs and cats. The metallic, threaded Ternamian EndoTIP cannula is used without a trocar and, thus, offers a safer entry technique and reduced slippage.4,5

For the secondary operative/cranial portal in cats and small dogs (< 20 lb), I use a 5-mm cannula-trocar assembly. In small patients in which I am concerned about instrument interference, I use the PassPort trocar (Patton Surgical), which is shorter (55 x 5 mm), for the operative/cranial portal. In medium (> 20 lb) and large dogs, I use a 10- to 14-mm cannula-trocar assembly. I have found that using a larger-diameter cranial cannula-trocar assembly in larger patients facilitates ovarian extraction, and the surgeon is less likely to drop the ovary or seed the abdomen with ovarian tissue during extraction. I use Autosuture's Versaport cannula-trocar assembly equipped with the Versaseal feature (Covidien) as the operative/cranial portal in medium and large dogs because it often allows ovarian extraction without losing the pneumoperitoneum.

  • An adjustable surgical table or tabletop positioner that allows patient repositioning intraoperatively, rotating right or left to elevate one side. I use the TT Endoscopic Positioner (Apexx Equipment) (Figure 1).
  • A laparoscopy tower (Figure 2) with a video monitor, a camera, a computer with recording hardware and software (I use AIDA Vet software [Karl Storz]), a camera head, an insufflator, a carbon dioxide gas cylinder (with full backup tank available), an insufflator line, a light source (with backup bulb), and a light cable. Ensure that the camera head, insufflator line, and light cable have been gas-sterilized or that sterile camera sleeves (e.g. Karl Storz) are available. When placing a sterile sleeve on the light cable, make sure the tape that secures the sleeve to the cable end does not depress the release where the cable attaches to the laparoscope.
  • A large gas-sterilized box (I use a Stack and Store Tool Box [Plano Molding] with -in drilled vent holes; Figure 3) containing the laparoscope and other surgical instruments and supplies needed for the procedure: four towels (inside), a large paper drape (outside, on top, and large enough to completely cover the patient and the instrument stand at the tail end of the surgery table), a Veress needle, an insufflation hose, a camera head, a light cable, a large needle holder, a No. 2 nylon suture with a large swaged needle (e.g. Ethilon 2 with cutting LR needle [Ethicon]), an EndoTIP 6-mm threaded cannula, a 5-mm cannula-trocar assembly, a 10- to 14-mm Versaport or equivalent cannula-trocar assembly, and endoscopic Babcock or rat-toothed forceps or graspers (e.g. V. Mueller Endolap 5-mm cobra-toothed grasper [Cardinal Health]). All cannulas should have an insufflation stopcock for added flexibility. I use pipe insulation with cutouts to protect the laparoscopes and EndoTIP cannulas inside the box. Additionally, the large sterile wrapper used for this box can be spread on the countertop for endoscopic instrument placement.
  • A general surgery pack and a No. 11 blade if using the Storz EndoTIP; otherwise use a No. 15 blade.
  • A bipolar electrosurgical unit or equivalent. Although this procedure can be performed with other endosurgical coagulation or ligation instruments, including lasers6 and harmonic scalpels,7 I use the LigaSure Vessel Sealing System (Valleylab) with a 5-mm LigaSure V Sealer/Divider hand piece for cats and small to medium dogs and a 10-mm LigaSure Atlas Sealer/Divider hand piece for medium-large to large dogs. Since this is a bipolar computer-driven vessel sealing and cutting system, no grounding plate is needed. Vessel sealing is activated with the power button on the instrument handle or the foot pedal, and it automatically deactivates once the proper amount of sealing energy has been delivered.
  • 10-mm Autosuture Endo Clips (Covidien) vascular clips. Keep these vascular clips in reserve in the rare case of uncontrolled bleeding.
  • A laparoscopic suction or irrigation unit.
  • Wall-mounted monitors on each side of the surgery table will greatly facilitate the procedure.

CAUTIONS AND CONTRAINDICATIONS


Table 1: Contraindications for Laparoscopy
If uterine disease is present (pyometra or mass) or if the animal is pregnant, it is best to perform or convert to an open procedure. When removing an enlarged uterus or an ovarian mass through a small portal site, a risk of rupturing the uterus or seeding the abdomen with tumor cells exists. However, if the diseased or gravid uterus can be safely removed laparoscopically, a third portal would need to be created just cranial to the brim of the pelvis on the midline, and the entire uterus with both ovaries attached would be removed through this most caudal portal (see "Laparoscopic-assisted ovariohysterectomy: An overview" in this article). The contraindications for laparoscopy are listed in Table 1.


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Source: VETERINARY MEDICINE,
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