Standing hand-assisted laparoscopic ovariectomy in 65 mares

Objective: To review the efficacy and safety of unilateral ovariectomy by use of a standing hand‐assisted laparoscopic approach and evaluate the effect of ovary size on posttransection hemorrhage after application of a linear stapling device. Study Design: Case series. Animals: Horses (n=65) aged 2–20 years. Methods: Medical records of mares that had ovariectomy performed by use of a standing hand‐assisted laparoscopic approach were reviewed. Data retrieved were signalment, ovary removed (left, right), ovarian size, ovarian pathology, intraoperative and postoperative complications, and length of hospitalization. Results: Mean ovarian diameter was 17 cm. Histopathology (52 mares) confirmed 41 granulosa cell tumors (79%), 8 ovarian cysts (15%), 1 teratoma (2%), and 2 ovaries (4%) without abnormalities. Hemorrhage was observed laparoscopically in 16 mares after transection of the mesovarium. Complications encountered during surgery included 1 mare collapsing in the stocks and 1 mare that hemorrhaged excessively from the incision. Postoperative complications included 2 cases of mild colic. Overall complication rate was 6%. Conclusions: All attempts to remove the target ovary were successful. The approach is safe for the mare, as complications encountered were similar to those recently reported for other approaches.     

Bilateral laparoscopic ovariectomy in standing mares: 22 cases

OBJECTIVE: To describe a technique for laparoscopic bilateral ovariectomy in standing mares and report the outcome of 22 clinical cases. STUDY DESIGN: Prospective study. ANIMALS OR SAMPLE POPULATION: A total of 22 mares between 4 and 23 years of age, weighing between 360 and 600 kg. METHODS: Mares with normal ovaries, as determined by palpation per rectum, were restrained in standing stocks and sedated with detomidine (0.01 to 0.02 mg/kg intravenously [i.v.]) and butorphanol (0.01 to 0.02 mg/kg i.v.). The laparoscope and instrument insertion sites were infiltrated with 2% lidocaine before incision. One laparoscope portal and two instrument portals were located in each paralumbar fossa. Ovariectomy was accomplished by intracorporeal dissection and ligation of the ovarian pedicles. The two instrument portals in each flank were ultimately connected resulting in a 4 to 5 cm laparotomy to facilitate ovarian removal. RESULTS: No major operative or postoperative complications occurred. Minor complications included incomplete hemostasis of an ovarian pedicle with a single ligature (three mares), transient inappetence, pyrexia and incisional infection. Owner satisfaction and cosmetic results were considered excellent. CONCLUSIONS: Standing laparoscopic ovariectomy appears to eliminate many of the potential complications associated with traditional surgical methods for ovariectomy and avoids the risk of general anesthesia. CLINICAL RELEVANCE: This technique requires minimal laparoscopic instrumentation and will provide surgeons with an alternative approach for bilateral ovariectomy in mares.     

Evaluation of a vessel-sealing device for use in laparoscopic ovariectomy in mares

OBJECTIVE: To evaluate a vessel-sealing instrument (LigaSure) as a method for hemostasis of the ovarian vasculature. STUDY DESIGN: Prospective study. ANIMALS OR SAMPLE POPULATION: Thirteen mares (8 experimental, 5 patients), aged 2 to 20 years and weighing 405 to 500 kg. METHODS: Thirteen mares had standing bilateral laparoscopic ovariectomy using a vessel-sealing device (LigaSure) to provide hemostasis. Eight reproductively normal experimental mares were divided into 2 groups: 1 group was re-examined laparoscopically 72 hours and the other group 10 days after the initial standing laparoscopic ovariectomy. The vessel-sealing device uses high current and low voltage, along with pressure, to reorganize the collagen into a translucent seal to achieve hemostasis of the ovarian vasculature. RESULTS: No major operative or postoperative complications were encountered. Complete hemostasis of the ovarian pedicle was accomplished. One mare had a fever for 24 hours' postoperatively; this responded to a single dose of flunixin meglumine. CONCLUSIONS: The LigaSure appears to be a safe method for hemostasis of the ovarian vasculature. CLINICAL RELEVANCE: Benefits of the LigaSure include no foreign material remaining in the abdomen and minimal to no need for surgical dissection before application. The LigaSure eliminates complications with potential ligature slippage and bleeding during dissection.     

Unilateral and bilateral laparoscopic ovariectomy of mares by electrocautery

Twelve horses underwent standing laparoscopic ovariectomy using electrocoagulation and fine dissection as the only means of achieving haemostasis of the severed ovarian pedicle. Four mares had bilateral ovariectomy performed as a treatment for aggressive behaviour thought to be associated with the oestrous cycle. Eight mares had unilateral ovariectomy performed for removal of a granulosa thecal cell tumour (gct). Electrocoagulation provided an effective means of haemostasis in both normal and pathological ovaries. Only one case (removal of a gct) had mild haemorrhage following electrocoagulation, necessitating the need for the application of endoscopic clips to achieve haemostasis. Six of the horses developed minor wound complications (none of them requiring any additional treatment). Long-term follow-up information showed complete resolution of abnormal behaviour in all eight horses with gcts, but in one of the four horses with normal ovaries the aggressive behaviour had not been completely resolved.     

Intraoperative pain responses following intraovarian versus mesovarian injection of lidocaine in mares undergoing laparoscopic ovariectomy

OBJECTIVE: To compare intraoperative pain responses following intraovarian versus mesovarian injection of lidocaine in mares undergoing laparoscopic ovariectomy. DESIGN: Randomized controlled trial. ANIMALS: 15 mares between 4 and 20 years old. PROCEDURE: Standard bilateral laparoscopic ovariectomy was performed. Prior to manipulation of the ovary, 2% lidocaine (10 mL) was injected into the ovary and saline (0.9% NaCI) solution (10 mL) was injected into the mesovarium on 1 side, with saline solution (10 mL) injected into the ovary and 2% lidocaine (10 mL) injected into the mesovarium on the other side. Presence (yes vs no) and severity (visual analogue scale) of pain were scored at 5 times (grasping of the ovary, dissection of the mesosalpinx, tightening of the first loop ligature, tightening of the second loop ligature, and transection of the ovarian pedicle) by 2 individuals blinded to treatment and each other's observations. RESULTS: During 4 of the 5 observation periods, significantly fewer mares had signs of pain following mesovarian injection of lidocaine, and during 2 of the 5 observation periods, visual analogue scale score was significantly lower. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that mesovarian injection of lidocaine is associated with significantly lower pain responses, compared with intraovarian injection, in horses undergoing laparoscopic ovariectomy.     

Luteoma in two mares treated by ovariectomy

A 15-year-old Paint mare (Case 1) and a 15-year-old Arabian mare (Case 2) were presented for aggressive and undesired behaviour. Reproductive evaluation revealed, initially, an enlarged ovary with a smaller/normal sized contralateral ovary in each case. Granulosa cell tumour (GCT) panel testing revealed elevated inhibin B in both cases and elevated anti-Mullerian hormone (AMH) levels only in Case 1 determined from currently established reference ranges. Based on a presumptive diagnosis of GCT, bilateral standing ovariectomy was elected for both mares. In each case neoplastic tissue consistent with luteoma was detected only on histological examination in the smaller/normal sized left ovary; the right ovary appearing normal. Long-term follow-up was performed 1 year and 5 years post-operatively by telephone. The owners were satisfied with the outcome and each patient demonstrated resolution of aggressive stallion-like behaviour. Each case returned to the owners' intended use. In conclusion, luteoma should be considered as a differential diagnosis for ovarian neoplasms in horses related to behavioural abnormalities, even in normal-sized ovaries.     

Laparoscopic ovariectomy in mares using a polyamide tie-rap

OBJECTIVE: To describe use of a polyamide tie-rap to ligate the mesovarium during standing laparoscopic ovariectomy in mares. STUDY DESIGN: Prospective study. ANIMALS: Ten mares. METHODS: Bilateral ovariectomy was performed in 10 mares. Standing laparoscopic ovariectomy was performed using 3 portals in the paralumbar fossa. A commercial polyamide tie-rap was prepared as a loop and marked with 4 colored lines close to the buckle, to enable us to check whether the loop was tightened securely. The ovary was grasped with forceps and after the mesovarium was minimally transected cranially and caudally, the loop of the tie-rap was inserted in the abdomen and placed around the mesovarium. It was firmly tightened, until at least 3 of the 4 marks were visible, then the end of the tie-rap was cut. The ovary was transected and removed through an enlarged 3rd portal. The contralateral ovary was removed similarly through the opposite paralumbar fossa. Repeat laparoscopy was performed in 8 mares, 2, 3, 4, and 12 weeks later. RESULTS: None of the mares had postoperative discomfort. On repeat laparoscopy, there was complete encapsulation of the stump and tie-rap after 3-4 weeks. In 2 mares, an adhesion between the left stump and the mesentery of the descending colon was observed. CONCLUSION: Ligation of the mesovarium can be easily and safely performed using a polyamide tie-rap during standing laparoscopic ovariectomy in mares. CLINICAL RELEVANCE: Standing laparoscopic ovariectomy using a polyamide tie-rap is a safe, technically easy and reliable surgical procedure in the mare.     

Use of an ecraseur for ovariohysterectomy in mares.

Ovariohysterectomy was performed in 20 mares at three stages of estrus. An ecraseur was used to severe the ovarian branch of the ovarian artery and vein and the ovarian suspensory ligament en masse. All other vessels supplying the ovaries and uterus were doubly ligated and transected. All mares survived. Complications were intraoperative hemorrhage in three mares, postoperative vaginal bleeding in two mares, and a hematoma in the remnant of the broad ligament in one mare. No adhesions between the uterine stump or remnants of the broad ligament and abdominal structures were detected by palpation per rectum.     

Instrument associated complication of a laparoscopic ovariectomy

The case reported here describes the retrieval of the end of a pair of laparoscopic forceps that became separated from the instrument shaft during a laparoscopic ovariectomy. This case details the procedures used to locate and remove the foreign body from the abdominal cavity. No complications associated with the intra‐abdominal foreign body occurred and the mare was discharged the following day.     

Feasibility of single-portal access laparoscopic ovariectomy in 17 cats

Laparoscopic ovariectomy (LapOVE) using single-portal access was attempted in 17 client-owned cats of different breeds admitted for elective ovariectomy. A 12 mm umbilical portal was placed 1 cm caudal to the umbilicus with the cat in dorsal recumbency. Then, a laparoscope with an operating channel was introduced into the portal with the cat in lateral recumbency. The right ovary was pulled to the abdominal wall using grasping forceps and fixed to the abdominal wall by a transabdominal suspension suture. The ovarian vasculature, suspensory ligament and proper ligament were progressively cauterised and transected with multifunction bipolar electrocoagulation forceps. The resected right ovary was exteriorised through the umbilical portal cannula. The left ovary was then removed from the abdomen in a similar fashion. Surgical time, intraoperative haemorrhage, amount of fat in the ovarian ligament, surgical complications and postoperative pain were recorded. The mean (sd) surgical time was 23 minutes and seven seconds (five minutes and 55 seconds). Intraoperative blood loss and fat deposition of the ovarian ligament were minimal. No intra- and postoperative complications were encountered. No cats needed rescue analgesia within 24 hours postsurgery.     

Evaluation of the harmonic scalpel for laparoscopic bilateral ovariectomy in standing horses

OBJECTIVE: To evaluate use of the Harmonic Scalpel (Ethicon Endo-Surgery Inc., Cincinnati, OH) for performing laparoscopic bilateral ovariectomy in standing horses. STUDY DESIGN: Experimental study. ANIMALS: Eight mares aged 2-20 years and weighing 410-540 kg. METHODS: Standing laparoscopic bilateral ovariectomy was performed in 8 mares with normal reproductive tract anatomy. The Harmonic Scalpel (an ultrasonically activated instrument) was used to simultaneously transect and obtain hemostasis of the ovarian pedicle. Necropsy was performed on 4 mares 3 days after surgery and 4 mares 30 days after surgery. Gross and histopathologic evaluation of the ovarian pedicles was performed to characterize tissue reaction. RESULTS: Complete hemostasis of the ovarian pedicles was obtained in all mares. Median transection time for the ovarian pedicle was 28 minutes. Postoperative complications included transient fever, moderate subcutaneous emphysema, and incisional seroma formation. On necropsy examination, there were no signs of generalized peritonitis, postoperative hemorrhage, or adhesion formation. Mild to moderate acute inflammation and scar formation with moderate chronic inflammation at the ovarian pedicle was found at 3 and 30 days. Median depth of coagulation necrosis at 3 days was 2.87 mm. CONCLUSIONS: The Harmonic Scalpel appears to provide reliable hemostasis of the ovarian pedicle during elective laparoscopic ovariectomy in horses. Clinical Relevance-The Harmonic Scalpel represents a safe alternative to other methods of hemostasis during elective laparoscopic ovariectomy in horses.     

Use of gonadotropin-releasing hormone for hastening ovulation in transitional mares

Natural GnRH and its analog have potential for hastening ovulation in mares. A study was conducted to evaluate the efficacy of a GnRH agonist given either as an injectable or s.c. implant for induction of ovulation in mares. Forty-five seasonally anestrous mares (March) were assigned to one of three groups (n = 15/group): 1) untreated controls; 2) i.m. injection of the GnRH agonist buserelin at 12-h intervals (40 micrograms/injection for 28 d or until ovulation) and 3) GnRH agonist administered as a s.c. implant (approximately 100 micrograms/24 h for 28 d). Six mares per group were bled on d 0, 7, 14 and 21 after injection or insertion of implant. Samples were taken at -1, -.5 and 0 h and at .5, 1, 1.5, 2, 4, 6 and 8 h after GnRH. Additional daily samples were drawn for 28 d after injection or until ovulation. Samples were assayed for concentration of LH and FSH. Progesterone concentrations were determined in samples collected on d 4, 6 and 10 after ovulation. Number and size of follicles and detection of ovulation were determined by ultrasonography. Number of mares induced to ovulate within 30 d was 0 of 15, 7 of 15 and 9 of 15 for groups 1, 2 and 3, respectively. During treatment, follicle sizes were smaller for mares in group 3 (implant). The LH response to GnRH agonist (area under curve) was similar among groups at d 0 but was greater (P less than .05) for mares in group 3 on d 7 and 14 and groups 2 and 3 on d 21 than for controls. A similar pattern was detected for peak concentrations of LH after GnRH on d 0, 7, 14 and 21. Daily concentrations of LH remained low in untreated control mares compared with GnRH-treated mares throughout the sampling period. Concentrations of LH for mares in group 3 that ovulated were elevated greatly above those for group 2 mares, whereas concentrations of FSH were similar in both treatment groups prior to ovulation.     

Fertility of mares after unilateral laparoscopic tubal ligation

OBJECTIVE: To develop a technique for laparoscopic tubal (oviductal) ligation and to evaluate pregnancy rates for mares that ovulated ipsilateral or contralateral to the ligated oviduct. STUDY DESIGN: Randomized prospective clinical trial comparing pregnancy rates after unilateral laparoscopic tubal ligation. ANIMALS: Twelve mares of light horse breeds. METHODS: One oviduct in each of 6 mares was surgically ligated with a laparoscopic technique; 6 other mares served as nonligated controls. Mares with unilateral tubal ligations (UTL) were inseminated with 500 million progressively motile sperm during 1 cycle when the dominant follicle was ipsilateral to the ligation site and 1 cycle when the dominant follicle was contralateral to the ligation site. Control mares were bred during 2 cycles regardless of the side of the dominant follicle. Pregnancy examinations were performed on days 12, 14, and 16 after ovulation by transrectal ultrasonography. RESULTS: None of the mares became pregnant when ovulations occurred from the ovary adjacent to the ligated oviduct. All 6 mares became pregnant on the first cycle when an ovulation occurred from the opposite ovary. Control mares became pregnant on 10 of 12 cycles (83.3 %). CONCLUSIONS: UTL was completely effective in preventing pregnancy when ovulation occurred ipsilateral to the ligation site. The surgical procedure did not interfere with the establishment of pregnancy when ovulation occurred from the contralateral ovary. CLINICAL RELEVANCE: UTL may be a clinically useful procedure for preparing a recipient mare for gamete intrafallopian transfer. The recipient mare could be allowed to ovulate and UTL would prevent fertilization of her oocyte but would not interfere with normal corpus luteum formation. The donor oocyte could be placed into the oviduct contralateral to the UTL site.