Contributors: Philip Lhermette, Eric Monnet

 Species: Feline   |   Classification: Techniques

Introduction Requirements Preparation Procedure Aftercare Outcomes Further Reading

Introduction

  • Ovariectomy is a viable alternative to ovariohysterectomy   Ovariohysterectomy   in the dog and cat and has been practised in Europe since 1981. Ovariectomy is less complicated, less time consuming and produces less morbidity than ovariohysterectomy and is therefore the procedure of choice for gonadectomy in the healthy bitch. Laparoscopic ovariectomy reduces morbidity further and speeds recovery.
Print off the owner factsheet on Laparoscopic ovariectomy (keyhole spay) to give to your client.

Uses

  • A minimally invasive technique for surgical removal of the ovaries in dogs and cats.

Elective

  • Prevention of estrus.
  • Control of breeding.
  • Prophylaxis of mammary neoplasia Mammary gland: neoplasia if performed early - preferably before first season.
  • Reduced prevalence of acquired inguinal hernias Inguinal hernia.

Ovarian disease

  • Neoplasia Ovary: neoplasia.
  • Abnormal estrus cycles.
  • Ovarian cysts.
  • Uterine disease.
  • Prevention/prophylaxis of pyometra Pyometra /cystic endometrial hyperplasia (CEH).

Vaginal disease

Systemic disorders

Advantages

  • Reduced soft tissue trauma.
  • Reduced peri-operative pain.
  • Reduced hemorrhage.
  • Faster recovery.
  • Smaller wounds - less interference from patient and no buster collar required.
  • Improved surgical visualization.
  • As for open ovariohysterectomy, significantly reduces incidence of mammary tumors if done early.
  • Relatively safe procedure.

Disadvantages

  • Requires additional instrumentation/expense.
  • Requires laparoscopic training Laparoscopy.
  • As for open ovariohysterectomy, may predispose to urinary incontinence Urinary incontinence and obesity.

Technical Problems

  • Requires considerable practice and training.
  • Requires excellent hand/eye coordination.
  • Need to accustom to working in a 2 dimensional environment on a monitor.

Alternative Techniques

Time Required

Preparation

  • 15 minutes.

Procedure

  • 8-30 minutes. Usually faster than open procedure as smaller wounds to close.

Decision Taking

Criteria for choosing test

  • Always inform owner you are doing ovariectomy and leaving uterus in situ.
  • Always inform owner you may need to convert to an open procedure.
  • Always inform owner you may need to remove uterus if any uterine pathology seen at surgery - can convert to laparoscopic ovariohysterectomy.
  • Can be performed on any age of dog or cat but older patients more likely to have uterine pathology
  • Preoperative evaluation - full blood count, renal and hepatic function.

Risk assessment

  • Any history of pyometra or vaginal discharge.
  • Obesity Obesity can hinder visualization and increase procedural difficulty.
  • Empty the bladder to prevent iatrogenic injury and increase abdominal space.
  • Pregnancy.
  • Concurrent systemic disease - diabetes mellitus.
  • Family history of bleeding disorders Hemostatic disorders: inherited.

Requirements

Personnel

Veterinarian expertise

  • Training and experience in laparoscopic procedures.

Anesthetist expertise

  • Understanding of the effects of insufflation on venous return, cardiac output, ventilation and oxygenation.

Nursing expertise

  • Equipment and theater set up.
  • Operation of endoscopy tower including insufflator and electrosurgical equipment.
  • Operation of image capture equipment.
  • Equipment cleaning and sterilization.

Materials Required

Minimum equipment

  • Monitor.
  • Camera system.
  • Rigid endoscope (5 mm 0° for medium to large dogs, 2.7 mm 30° for small dogs and cats).
  • Examination sheath for 2.7 mm 30° rigid endoscope.
  • Light guide cable.
  • Light source - preferably xenon or metal halide.
  • Automatic CO2 insufflator with CO2 cylinder.
  • Two 6 mm laparoscopic cannulae with trocars (or Ternamian" tipped cannulae) - three for ovariohysterectomy.
  • An 11 mm laparoscopic cannula with trocar and 5 mm reducer.
  • A 3.6 mm laparoscopic cannula and trocar (or Ternamian" tipped cannula) for cats and small dogs.
  • Laparoscopic instruments - Babcock forceps, palpation probe, bipolar forceps and lead, scissors.
  • Electrosurgery generator (bipolar).
  • Large curved suture needle and suture material.
  • Veress needle and insufflation tubing.
  • No 11 scalpel blade and handle.
  • Standard laparotomy surgical pack.

Ideal equipment

  • Ovariectomy hook.
  • Bipolar vessel sealer/cutter.
  • Ultrasonic dissector/sealer.
  • Endograb" device.

Minimum consumables

  • Bupivacaine Bupivacaine local analgesic (1.5 mg/kg total).
  • 3:0 USP/2 Metric polyglactin 910 absorbable suture for closing linea alba.
  • Skin glue.

Other requirements

  • Ovariectomy may be performed as a single port, two port or three port technique.
  • The two port technique is most common and least invasive but requires a wider coat clip unless an endograb device is used.
  • If using a single port technique an 11mm operating laparoscope will be required, together with suitable 5 mm instrumentation to fit the operating channel. This may be rather cumbersome for small dogs and cats, and requires a larger incision and more specialized instrumentation.
  • If using a three port technique a third cannula is introduced in the midline just cranial to the pubic bone and Babcock's forceps are introduced through this port to grasp the ovary and hold it for dissection instead of using a percutaneous hook or needle. This reduces the width of hair clip needed but requires an additional incision.

Preparation

Pre-medication

  • As for laparotomy.

Dietary Preparation

  • Fast for 12 hours before surgery.

Site Preparation

  • As for laparotomy.
  • If using a needle or ovariectomy hook to suspend ovary, make a wide clip down the costal arch to just below the lateral processes of the lumbar vertebrae and back up to the caudal abdomen in a diamond shape.
  • Drape in a square pattern with the corners on the midline and at the apex of clip on each flank.

Other Preparation

  • Empty the bladder.
  • Inject local analgesic at each port site (bupivacaine).
  • Place endoscopy tower and monitor at the head of the patient, preferably so monitor can be moved to each side opposite the surgeon.

Procedure

Approach

Step 1 - Placement of Veress needle

  • Inject bupivacaine in midline 3-6 cm cranial to umbilicus.
  • Make a small stab incision through the skin at this site with a No 11 scalpel.
  • Palpate spleen and move from midline if possible.
  • Grasp abdominal wall at umbilicus between finger and thumb and elevate.
  • Insert Veress needle through linea alba in caudolateral direction into the pocket thus formed.
  • Confirm correct placement by lateral movement on peritoneum, hanging drop method and drawing back on syringe attached to luer port.

Step 2 - Insufflation of abdomen

  • Connect insufflation tubing to insufflator and veress needle.
  • Insufflate abdomen to a maximum pressure of 6-10 mm Hg depending on size of patient (4-8 mm in cats).

Step 3 - Placement of first cannula

  • Inject site 2-6 cm caudal to umbilicus on midline with bupivacaine.
  • Make a 4-5 mm skin incision for a 6 mm cannula (2.5 mm incision for a 3.6 mm cannula) at this site (if using Ternamian" tipped cannula make a small stab incision in the linea alba).
  • Insert cannula through the linea alba until gas is heard escaping. Do not press down too hard to prevent iatrogenic damage to organs under the port site.
  • Remove the trocar.
  • White balance the camera and insert the endoscope with camera attached.
  • Inspect the abdomen.

Step 4 - Placement of second cannula

  • All instruments and cannulae  are now inserted into the abdomen under direct visual guidance.
  • Remove the Veress needle and enlarge the skin incision to 4-5 mm (9-10 mm if using an 11 mm cannula in a large or obese dog).
  • Introduce the second cannula in a controlled manner pointing slightly laterally to avoid direct entry into the falciform fat. Observe the entry on the monitor via the endoscope.
  • Introduce a palpation probe under direct visual guidance and examine the whole abdomen.
  • Examine both uterine horns to the cervix.

Core Procedure

Step 1 - First ovary

  • Withdraw endoscope into cannula and remove the palpation probe.
  • Rotate patient on the table into 45° left lateral recumbency.
  • Introduce Babcock's forceps into the cranial port under visual guidance and pass them down to the ovary under visual guidance. Insert one jaw into the ovarian bursa, close and clamp the forceps and elevate the ovary to the lateral abdominal wall.
  • Drop the handle of the Babcock's and leave the ovary suspended.

Step 2 - Fixate the ovary

  • Ballot the lateral abdominal wall with the tip of the ovariectomy hook or large curved needle. Introduce the hook or needle directly behind the ovary and pass it down and through the ovarian pedicle directly below the ovary, then up and around the ovary to suspend it against the abdominal wall. Lay the ovariectomy hook down. If using a needle, suture material is passed around the ovary and then clamped outside the body with hemostats.
  • Remove the Babcock's forceps from the abdomen.
  • If using an Endograb" device this is introduced in the same way as the Babcock's forceps and the first hook is placed in the ovarian bursa. The device is released and the second arm is picked up and elevated to the abdominal wall. The second hook is activated to attach the device to the abdominal wall.

Step 3 - Ovarian dissection

  • Introduce bipolar forceps or bipolar vessel sealing device into the cranial port under direct visualization.
  • Grasp the pedicle immediately below the ovary to seal the ovarian artery and vein. Dissect close to the ovary to reduce the amount of fat and tissue that must be removed from the port. Cut the sealed tissue with the vessel sealer or replace the bipolar forceps with scissors and cut.
  • Take care not to make contact with the peritoneal wall.
  • If the ovary has fallen slightly cranial to the hook, grasp the ovarian ligament and seal then cut it. Finally grasp the proper ligament and seal and cut it, leaving the ovary free on the abdominal wall.
  • If the ovary falls caudal to the hook dissect the proper ligament first and then the ovarian ligament to prevent the ovary falling off the hook.
  • Following dissection, check the area caudal to the kidney for any hemorrhage. Any bleeding vessels can be easily grasped and sealed with bipolar forceps.

Step 4 - Removal of the ovary

  • Remove the vessel sealers or scissors from the abdomen.
  • Introduce Babcock's forceps under direct visualization and grasp the ovary taking care to grasp fibrous tissue at one end Laparoscopy: ovariectomy - suspend ovary . Grasping fat will allow the ovary to slip off during removal.
  • Remove the ovariectomy hook or suture needle and withdraw the ovary to the mouth of the cannula.
  • Withdraw the endoscope into the cannula and rotate the patient back into dorsal recumbency to realign the skin and linea alba incisions.
  • Remove the cranial cannula by sliding up the shaft of the Babcock's keeping firm hold of the ovary with the forceps.
  • Gently remove the ovary through the abdominal wall with a back and forward twisting motion. It may be helpful to grasp the ovary with hemostats as it comes into view.
  • In fat or large bitches it may be necessary to place an 11 mm cannula with reducer to retrieve the ovary.

Step 5 - Closure

  • Replace the cranial cannula. It is sometimes helpful to place closed Babcock forceps through the cannula and into the incision to act as a "guide wire" for replacing the cannula.
  • Rotate the patient into 45° right lateral recumbency.
  • Replace the endoscope and visualize the left kidney and ovary.
  • If the spleen obscures the view it may be necessary to rotate the patient almost into left lateral recumbency and then back to 45° to move the spleen out of the way.
  • The procedure is the repeated on the left ovary.
  • Following removal of both ovaries, check the abdomen for any hemorrhage and them remove all instruments and the endoscope.
  • Remove the cranial cannula.
  • Remove the valve unit from the caudal cannula to allow the abdomen to desufflate completely.
  • Elevate the abdominal wall a few times with the cannula to flush any remaining CO2 out.
  • Remove the cannula.
  • Close the linea alba at each site with 3:0 USP/2 Metric polyglactin 910 absorbable suture.
  • Close skin with intradermal suture or skin glue.

Aftercare

Immediate

Monitoring

  • As for standard laparotomy procedure. Monitor pain, temperature, heart and respiratory rate, defecation, urination, food and water.

Fluid requirements

  • As for standard laparotomy procedure.

Analgesia

  • Single dose of NSAID (meloxicam Meloxicam, carprofen Carprofen) with the pre-medication is usually sufficient, together with local analgesia at the port sites.

Antimicrobial therapy

  • Not usually required.

Wound Protection

  • None.

Special precautions

  • Reduced exercise for 2-3 days.

Potential complications

  • As for laparotomy.
  • Wound infection/dehiscence rare as wounds small and less often subject to self trauma.

Outcomes

Complications

  • Potential for laceration of spleen when introducing Veress needle or first cannula.
  • Potential for laceration/puncture of bladder if not emptied before procedure.
  • As for laparotomy.

Prognosis

  • Excellent.

Reasons for Treatment Failure

  • Conversion to open laparotomy due to surgeon inexperience in laparoscopic procedures.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Culp W T, Mayhew P D & Brown D C (2009) The Effect of Laparoscopic Versus Open Ovariectomy on Postsurgical Activity in Small Dogs. Vet Surg 38 (7), 811-817 PubMed.
  • van Goethem B V, Schaefers-Okkens A, Kirpensteijn J (2006) Making a rational choice between ovariectomy and ovariohysterectomy in the dog: A discussion on the benefits of either technique. Vet Surg 35 (2), 136-143 PubMed.
  • Devitt C M, Cox R E, Hailey J J (2005) Duration, complications, stress, and pain of open ovariohysterectomy versus a simple method of laparoscopic-assisted ovariohysterectomy in dogs. J Am Vet Med Assoc 227 (6), 921-7 PubMed.
  • Davidson E B, Moll H D, Payton M E (2004) Comparison of laparoscopic ovariohysterectomy and ovariohysterectomy in dogs. Vet Surg 33 (1), 62-69 PubMed.
  • Okkens A C, Kooistra H S, Nickel R F (2003) Comparison of long term effects of ovariectomy versus ovariohysterectomy in bitches. Der Praktische Tierarzt 84 (2), 98-101 VetMedResource.

Other sources of information

  • Freeman L (2012) Operative Laparoscopy; Ovariectomy, ovariohysterectomy. In: Clinical Manual of Small Animal Endosurgery. Hotston-Moore A & Ragni R A(Ed) Wiley-Blackwell, pp 143-147.
  • Hutchison R (2011) Laparoscopic spay of the female canine and feline. In: Small Animal Endoscopy 3rd edn. Tams T and Rawlings C (Ed), Mosby. pp 466-477.
  • Lhermette P, Monnet E, Sobel D (2008) Rigid Endoscopy: laparoscopy. In: Canine and Feline Endoscopy and Endosurgery, Lhermette P, Sobel D (Ed), BSAVA, Gloucester, pp 158-174.
  • Hancock R B, Lanz O I, Waldron D R et al (2004) Comparison  of postoperative pain following ovariohysterectomy via harmonic scalpel-assisted laparoscopy versus traditional ovariohysterectomy in dogs. ACVS Scientific Presentation Abstracts; E18.