Le Docteur Rossignol est un des fondateurs de la clinique de Grosbois. Il y travaille depuis 1986 avec le Docteur Corde qui est maintenant parti à la retraite.
Diplômé de l’Ecole Nationale Vétérinaire de Maisons-Alfort, il est passionné de chirurgie depuis le début de son activité. Il est diplômé du titre de spécialiste en chirurgie « ECVS » depuis 2011 et il est reconnu mondialement pour les techniques qu’il a développées en chirurgie de la gorge et des fractures. Il est appelé fréquemment à opérer en Europe mais aussi aux Etats Unis, Afrique du Sud, Japon, Australie.
Fabrice Rossignol forme des chirurgiens au diplôme de spécialiste et son équipe produit des nombreuses publications de renommée internationale, à l’instar des meilleures écoles Américaines. Il est également formateur permanent pour l’AO Vet et convié à de nombreux congrès.
Beste KJ, Ortved KF, Rossignol F, Ducharme NG. Transendoscopic correction of epiglottic entrapment with a silicone- covered laser guide and diode laser in 29 horses. Vet Surg. 2020 Jan;49(1):131-137.
Objective: To describe the use of a silicone-covered laser guide and diode laser for surgical correction of epiglottic entrapment and report postoperative outcomes in horses with epiglottic entrapment.
Study design: Retrospective case series.
Animals: Thoroughbred and standardbred racehorses (n = 29) with epiglottic entrapment.
Methods: A silicone-covered laser guide was placed endoscopically to direct the diode laser cutting action during transection of the entrapping subepiglottic membrane and to act as a physical barrier between the membrane and the epiglottic cartilage. Postoperative complications and trainer satisfaction were recorded via use of a follow- up questionnaire. Race records were reviewed to determine return to racing and detect differences in the number of starts, wins, or earnings before and after surgery. Results: The entrapping membrane was successfully released in all horses. Mild postoperative complications such as swelling of the surgical site (12 horses) and coughing or mild nasal discharge (5 horses) were recorded during the first few days after surgery. Ninety-six percent of trainers were satisfied with the outcome of the procedure; 93% of horses returned to racing.
Conclusion: Laser guide-assisted transection of the subepiglottic membrane corrected epiglottic entrapment in standing horses.
Clinical significance: Ease of surgical technique, mild postoperative complications, and a good prognosis to return to racing make this a suitable alternative to the traditional laser procedure.
Brandenberger O, Martens A, Robert C, Wiemer P, Pamela H, Vlaminck L, Barankova K, Haspeslagh M, Perkins JD, Ducharme N, Rossignol F. Anatomy of the vestibulum esophagi and surgical implications during prosthetic laryngoplasty in horses.Vet Surg. 2018 Oct;47(7):942-950.
Objective: To describe the anatomy of the entry to the equine esophagus (vestibulum esophagi) and to assess the risk of penetrating its adventitia and/or lumen during laryngoplasty.
Study design: Ex vivo cadaveric study.
Sample population: Five isolated equine larynges and 39 equine head and neck specimens.
Methods: The anatomy of the vestibulum esophagi was studied by dissection of 5 cadaver specimens. Then, a bilateral laryngoplasty was performed, including 5 suture placements through the muscular processes, caudal, rostral, and sagittal, with straight and curved needles. Two of the 3 surgeons performing the implantations were unaware of the goals of the study. Suture positions and iatrogenic trauma to the lumen and/or adventitia of the vestibulum esophagi were identified during dissection of the specimens. Risk factors for penetrating the adventitia were evaluated with a multivariate regression model.
Results: The vestibulum esophagi spans between both wings of the thyroid cartilage over the entire width of the larynx, covering the rostral spine (arcuate crest) of the arytenoid cartilages. It is covered by the thyropharyngeus and cricopharyngeus muscles. Masked surgeons were associated with a significantly higher number of adventitia penetrations (72%) compared to the nonmasked surgeon (9%). The lumen of the vestibulum esophagi was penetrated in 4.6% of suture placements and only by the 2 masked surgeons.
Conclusion: Penetration of the adventitia was more common when surgeons were unaware of the anatomical extent of the vestibulum esophagi.
Clinical significance: Anatomical knowledge of the extent of the vestibulum esophagi reduces the risk of penetrating its lumen or adventitia during suture placement on the muscular process of the arytenoid cartilage.
Curtiss A, Goodrich L, Rossignol F, Richardson DW. Pancarpal and partial carpal arthrodesis with 3 locking compression plates in 6 horses. Vet Surg. 2018 Jul;47(5):692-704.
Objective: To report the outcome of horses after pancarpal or partial carpal arthrodesis with 3 locking compression plates (LCP).
Study design: Case series.
Animals: Six horses ranging in age from 8 months to 16 years and weighing 227-580 kg with severe carpal pathology including acute fractures, chronic osteoarthritis, and chronic angular limb deformity.
Methods: Pancarpal or partial carpal arthrodesis was performed with 3 LCP. Autologous cancellous bone grafts were used in 5 of 6 cases to facilitate joint arthrodesis.
Results: External coaptation was maintained for 4 to 6 weeks after surgery. Radiographic follow-up was available in all 6 cases, all of which reached arthrodesis and pasture soundness by 4-5 months postoperatively. One case required implant removal at 6 months because of implant exposure through the skin but returned to pasture soundness after removal.
Conclusion: Carpal instability due to acute fractures or chronic disease was successfully stabilized with 3 short LCP, leading to pasture soundness in all 6 horses.
Clinical significance: The use of 3 short LCP should be considered as a strategy to facilitate pancarpal or partial carpal arthrodesis by providing superior stability without placement of implants in the diaphysis of the radius and third metacarpus.
Brandenberger O, Rossignol F, Perkins JD, Lechartier A, Mespoulhès-Rivière C, Vitte A, Rossignol A, Ducharme N, Boening KJ. Ex vivo biomechanical stability of 5 cricoid-suture constructs for equine laryngoplasty. Vet Surg. 2017 Jul;46(5):705-713.
Objective: To determine the biomechanical properties of 5 suture constructs in the equine cricoid under cyclic loading and load to failure testing.
Study design: Ex vivo study.
Samples: Seventy-five equine cadaver larynges.
Methods: Each larynx was implanted with 1 of 5 cricoid-suture constructs. The standard laryngoplasty, where a suture is passed once through the cricoid, including its caudal edge, was used in 2 constructs: 1 with 5 USP Ethibond (ES) and 1 with 2 mm Fibertape (FS). In the third construct, the 2 mm Fibertape was passed twice through the cricoid including its caudal edge (Double Loop-DL). Constructs 4 and 5 used 2 mm Fibertape in a U-shaped loop passed through the cricoid but excluding its caudal edge. One construct was supported with a metallic button (MB) on the caudo-ventral aspect of the cricoid while the other included only the U-shaped loop (U). Constructs were subjected to cyclic loading and to single cycle to failure. Reduction of the left-to-right arytenoid angle quotient (LRQ), suture migration, and load at failure were compared.
Results: LRQ reduction after cyclic loading was lower in MB and U than ES constructs. During cyclic loading, suture migration was reduced in MB, U, and DL compared to ES constructs. Mean load at failure was lower in FS and U than in ES constructs.
Conclusion: Loss of abduction after equine laryngoplasty may be reduced and pullout forces increased by applying a MB construct in the cricoid cartilage. In vivo testing is required to verify these results.
Mespoulhès-Rivière C, Brandenberger O, Rossignol F, Robert C, Perkins J, Marie JP, Ducharme ND. Feasibility, repeatability, and safety of ultrasound-guided stimulation of the first cervical nerve at the alar foramen in horses. American Journal of Veterinary Research, November 2016, Vol. 77, No. 11, Pages 1245-1251.
OBJECTIVE: to develop and assess the feasibility, repeatability, and safety of an ultrasound-guided technique to stimulate the first cervical nerve (FCN) at the level of the alar foramen of the atlas of horses.
ANIMALS: 4 equine cadavers and 6 clinically normal Standardbreds.
PROCEDURES: in each cadaver, the FCN pathway was determined by dissection, and any anastomosis between the first and second cervical nerves was identified. Subsequently, each of 6 live horses underwent a bilateral ultrasound-guided stimulation of the FCN at the alar foramen 3 times at 3-week intervals. After each procedure, horses were examined daily for 5 days.
RESULTS: in each cadaver, the FCN passed through the alar foramen; a communicating branch between the FCN and the accessory nerve and anastomoses between the ventral branches of the FCN and second cervical nerve were identified. The anastomoses were located in the upper third of the FCN pathway between the wing of the atlas and the nerve’s entry in the omohyoideus muscle. Successful ultrasound-guided electrical stimulation was confirmed by twitching of the ipsilateral omohyoideus muscle in all 6 live horses; this finding was observed bilaterally during each of the 3 experimental sessions. No complications developed at the site of stimulation.
CONCLUSIONS AND CLINICAL RELEVANCE: results indicated that ultrasound-guided stimulation of the FCN at the alar foramen appears to be a safe and straightforward procedure in horses. The procedure may have potential for use in horses with naturally occurring recurrent laryngeal neuropathy to assess reinnervation after FCN transplantation or nerve-muscle pedicle implantation in the cricoarytenoideus dorsalis muscle.
Rossignol F, Brandenberger O, Mespoulhes-Rivière C. Internal Fixation of Cervical Fractures in Three Horses. Vet Surg. 2016 Jan;45(1):104-9.
Objective: To describe the surgical treatment outcome of cervical fractures in 3 horses.
Study design: Case report.
Animals: Three client-owned horses with cervical vertebral fractures.
Methods: Three horses were refered for neck stiffness, pain, and ataxia after a cervical trauma because of a fall. Radiographic examination showed an oblique displaced fracture of the caudal aspect of the body of the second cervical vertebra (C2) in horse 1, an oblique displaced fracture of the caudal aspect of C4 involving the disc between C4 and C5 in horse 2, and a displaced transverse fracture of the body of the axis (C2) extending to the lateral arches and involving the vertebral canal in horse 3. In horse 1, the fracture was reduced and stabilized using a 14-hole narrow DCP plate, applied ventrally, and fixed with cancellous screws. A cervical fusion was performed. In horses 2 and 3, fracture fixation was performed using a 5-hole narrow LCP and 5 mm locking screws.
Results: All horses showed improvement and returned to full activity. The fracture healed in all horses.
Conclusion: Internal fixation of cervical fracture in these horses was associated with minimal complications, and was associated with healing and a highly functional outcome in all horses. The LCP was preferred and would be recommended for ventral stabilization of selected cases of vertebral fractures.
Rossignol F, Vitte A, Boening J, Maher M, Lechartier A, Brandenberger O, Martin-Flores M, Lang H, Walker W, Ducharme NG. Laryngoplasty in standing horses. Vet Surg. 2015 Apr;44(3):341-7.
Objective: To describe the clinical experience with standing laryngoplasty in a series of horses mostly nonracing.
Study design: Case series.
Animals: Seventy-one client-owned horses.
Methods: Medical records (April 2008-February 2014) of horses treated by standing laryngoplasty for abnormal respiratory noise and or poor performance were reviewed. Horses were included if they had a diagnosis of idiopathic right or left recurrent laryngeal neuropathy confirmed by videoendoscopy. All horses underwent a unilateral laryngoplasty with a unilateral or bilateral ventriculectomy or ventriculocordectomy. Follow-up endoscopy was performed in all horses within 24 hours postoperative, in 24 horses at 2-weeks, and in 65 horses at 6 weeks. Late follow-up was obtained from the trainer, owner, or referring veterinarian by telephone.
Results: Laryngoplasty was performed under endoscopic guidance with the horses sedated, and the surgical site was desensitized with local anesthetic solution. Laryngoplasty was completed in all horses and was well tolerated. No hyperabduction was observed. Two horses developed incisional swelling that resolved with drainage only. Late follow-up reported satisfactory improvement in respiration in all but 3 horses.
Conclusions: Laryngoplasty performed with the horse standing avoids risks associated with general anesthesia and recovery and yields comparable results in nonracing horses, to laryngoplasty performed with the horse anesthetized. This technique reduces cost and allows accurate intraoperative adjustment of the degree of arytenoid abduction.
Lechartier A, Rossignol F, Brandenberger O, Vitte A, Mespoulhès-Rivière C, Rossignol A, Boening KJ. Mechanical comparison of 3 anchoring techniques in the muscular process for laryngoplasty in the equine larynx. Vet Surg. 2015 Apr;44(3):333-40.
Objective: To compare mechanical properties of 2 techniques with a conventional technique for anchoring the muscular process in a laryngoplasty procedure.
Study design: Experimental ex vivo study.
Sample population: Equine larynges (n = 60).
Methods: A single loop (SL), a screw (SC), and a double loop technique (DL) were compared. Constructs were subjected to cyclic loading, oscillating from 5 to 50 N for 3000 cycles, followed by a single cycle to failure test. Mean distraction, load at failure, stiffness, and failure mode were compared between groups.
Results: Mean ± SD distraction in cyclic loading was greater for DL (2.1 ± 0.7 mm) than for SL (1.9 ± 1.3 mm) and SC (1.539 ± 0.9 mm); however, there was no significant difference between SL and SC or between SL and DL. Mean ultimate failure load was greater for DL (240 ± 44.56 N) than for SC (189.59 ± 46.16 N) and SL (150.93 ± 44.43 N) and greater for SC compared with SL. Failure occurred by cartilage tearing for DL and SL, and by screw pull out (n = 13) or knot slippage (4) for SC.
Conclusion: In cyclic loading, SC is more stable than DL and at least as stable as SL. In single cycle to failure, DL is the strongest construct and SC is stronger than SL.
Rossignol F, Mespoulhes-Rivière C, Vitte A, Lechartier A, Boening KJ. Standing laparoscopic inguinal hernioplasty using cyanoacrylate for preventing recurrence of acquired strangulated inguinal herniation in 10 stallions. Vet Surg. 2014 Jan;43(1):6-11.
Objective: To describe a technique for standing inguinal hernioplasty in horses using cyanoacrylate glue, and to evaluate its effect on prevention of recurrent inguinal herniation in stallions that had previous acquired strangulated inguinal hernia (SIH).
Study design: Case series.
Animals: Stallions (n = 10) with a history of SIH.
Methods: Hernioplasty was performed in standing horses using 4 laparoscopic portals. The mesorchium was retracted caudomedially using Babcock forceps. A flexible polyethylene extension tube was introduced through the sheath of a laparoscopic needle and n-butyl-2-cyanoacrylate (2 mL) was injected into the inguinal canal including its margins while a 2nd Babcock forceps prevented deep ventral diffusion of the cyanoacrylate. The craniolateral parts of the vaginal ring were compressed until full adhesion between the visceral and parietal walls was achieved. In 2 horses, the lateral part of the vaginal ring was sutured before gluing. A contralateral approach was used to check the caudomedial part of the vaginal ring.
Results: No recurrence (1-4 years) of inguinal hernia was reported. No major complications occurred and cosmetic outcome was excellent. All horses were used for their intended purpose and 7 horses being used as breeding stallions remained fertile.
Conclusion: Standing inguinal hernioplasty using cyanoacrylate seems to provide efficient and secure closure of the vaginal ring in stallions.
Rossignol F, Vitte A, Boening J. Use of a modified transfixation pin cast for treatment of comminuted phalangeal fractures in horses. Vet Surg. 2014 Jan;43(1):66-72.
Objectives: To (1) report a modified transfixation pin cast technique, using dorsal recumbency for fracture reduction, distal positioning of the pins in the epiphysis and distal metaphysis, and a hybrid cast, combining plaster of Paris (POP) and fiberglass casting, and (2) report outcome in 11 adult horses.
Study design: Case series.
Animals: Adult horses (n = 11) with comminuted phalangeal fractures.
Methods: Horses were anesthetized and positioned in dorsal recumbency. The phalangeal fracture was reduced by limb traction using a cable attached to the hoof. Screw fixation in lag fashion of fracture fragments was performed when possible. Transfixation casting was performed using two 6.3 mm positive profile centrally threaded pins with the 1st pin placed in the epiphysis of the metacarpus/tarsus at the center of, or slightly proximal to, the condylar fossa and the 2nd one 3-4 cm proximal. A hybrid cast was applied.
Results: Forelimbs were involved in 9 horses and the hind limb in 2. Pins were maintained for a minimum of 6 weeks. No pin loosening was observed at the time of removal (6-8 weeks). A pony fractured the distal aspect of the metacarpus at the proximal pin. Nine horses survived (82%); none of the horses developed septic arthritis despite the distal location of the distal pin, close to the fetlock joint.
Conclusion: This modified transfixation pin casting technique was associated with good pin longevity and could reduce the risk of secondary pin hole fractures and pin loosening.
Rossignol F, Ouachée E, Boening KJ. A modified laryngeal tie-forward procedure using metallic implants for treatment of dorsal displacement of the soft palate in horses. Vet Surg. 2012 Aug;41(6):685-8.
Objective: To describe a modified laryngeal tie-forward procedure (LTFP) using metallic implants.
Study design: Retrospective case series.
Population: Twenty-seven horses (including 24 race horses) with dorsal displacement of the soft palate (DDSP) or palatal instability (PI) diagnosed using high-speed treadmill endoscopy (n = 15), history and resting examination (n = 8), or dynamic endoscopy over ground (n = 4).
Methods: All horses underwent the modified LTFP. Modifications of the surgical procedure consisted in the use of 3 metallic stents called Suture Button(TM) through which the sutures are threaded and in a tying technique that involved a single knot connecting left and right suture loops (versus tying each separately). Lateral radiographs were taken 24 hours after surgery. Follow-up was obtained by telephone communication with trainers or owners.
Results: Surgery was performed without complications on all horses. The 3 metallic buttons were clearly visible on the postoperative radiographic examination. No evidence of suture breakage was observed 24 hours postoperatively based on radiographs.
Conclusion: In other aspects, this technique is not very different from that originally described by Ducharme et al; it is an innovation that could offer some advantages to the surgeons and increase suture resistance to pullout from the thyroid cartilage. Our technique was used without complication in a small group of horses and return to performance may be similar to the original technique.
Rossignol F, Perrin R, Boening KJ. Laparoscopic hernioplasty in recumbent horses using transposition of a peritoneal flap. Vet Surg. 2007 Aug;36(6):557-62.
Objective: To evaluate the efficacy of a laparoscopic peritoneal flap hernioplasty (PFH) to close anatomically the vaginal ring and to evaluate its protective effect in horses with a history of strangulated inguinal hernia (SIH) against future herniation.
Study design: Prospective study.
Animals: A first group of 5 ponies, 3 horses and 1 donkey with no history of SIH and a second group of 4 horses ‘clinical cases’ with a history of SIH.
Methods: A laparoscopic PFH was effected on all horses under general anaesthesia. Peritoneum ventro-lateral to the vaginal ring was elevated and cut on 3 sides, separated from the underlying muscle, then inverted and attached dorso-medially and laterally to the parietal wall using intra-corporeal stitches (6 cases) or laparoscopic staples (7 cases). Animals of the first group (n=9) underwent a standing laparoscopy 7 days post-operatively to visualize the vaginal rings. Horses of the second group were followed to confirm the absence of re-herniation.
Results: The laparoscopic check-up showed that the vaginal ring had been effectively and completely covered in all cases except the first one. No adhesions was observed. In the four clinical cases, none of the horses have had a reccurence of SIH at the time of writing (6 months to 4 years).
Conclusion: Laparoscopic hernioplasty on a recumbent horse is feasible by closing the vaginal ring with a peritoneal flap. This technique was efficient in our cases to prevent recurrence of SIH but more cases are needed. This technique may reduce inflammation and irritation of the spermatic cord, which could otherwise jeopardise the animal’s breeding career.
Clinical relevance: Laparoscopic PFH coud be used in horses with a history of SIH.
Rossignol F, Perrin R, Desbrosse F, Elie C. In vitro comparison of two techniques for suture prosthesis placement in the muscular process of the equine arytenoid cartilage. Vet Surg. 2006 Jan;35(1):49-54.
Objective: To compare in vitro the load necessary for a partial and complete rupture of the muscular process arytenoid cartilage when a suture prosthesis is positioned by a bone trocar versus a trocar point needle and to compare failure mode.
Study design: Experimental using cadaver specimens.
Sample population: Larynges from 18 Thoroughbred race horses, aged 2-20 years.
Methods: Arytenoid cartilages were separated randomly into 2 groups: group 1-suture prosthesis inserted directly through the muscular process using a curved trocar point needle and group 2-suture passed through a hole predrilled with a 3 mm bone trocar. Distracting force (constant rate, 1 mm/s) was applied to the suture until failure of the muscular process. Partial failure load, maximum load at complete failure, and force-time curve were recorded. Each arytenoid cartilage was examined, radiographed, and classified as having a linear or curved failure plane.
Results: No significant differences in mechanical test variables were detected. Failure mode followed the fissures occurring at the beginning of failure and then followed the tension axis. Significantly more linear failures occurred in group 2 (trocar) and more curved failures occurred in group 1 (needle).
Conclusion: Use of a bone trocar for tunneling through the muscular process may reduce fissure formation.
Clinical relevance: Use of bone trocar to create a hole in the muscular process of the arytenoid cartilage for suture passage in laryngoplasty may reduce fissure formation and decrease the risk of cartilage failure from suture pullout.
Rossignol F: Removing the very large ovary. BEVA 2016.
The most common indication for ovariectomy in the mare is removal of granulosa cell tumors. When these tumors remain undiagnosed for prolonged periods, they may grow to a considerable size within the abdomen, making surgical removal quite a challenge. Large flank incisions increase surgical time for closure and increase the risk of complications during wound healing (seroma formation, wound dehiscence, infection) that may lead to a diminished cosmetic result. Flank incisions might also lead to depreciation in high level sport and race horses. Laparoscopy and laparoscopic-assisted remain the gold standard for removal such large ovaries and some techniques and strategies have been desbribed to reduce the size of the ovary and remove it, providing the benefits to mares afflicted with this condition. Dissection and hemostasis of the pedicle is no longer a major problem since the introduction of electrosurgical instruments. However, very large ovarian might have some adhesion with others organs, such as uterus or bowel that can also be challenging to dissect laparascopically.
Whatever the strategy for removal the ovary, the procedure is usually started using a standard standing laparoscopic technique in the same fashion as that for removal of normal ovaries
Food is withheld for 24 hours. We usually prefer to bed the mare with wood shavings and replace the hay by lucerne pellets 72 hours before surgery. The mare is restrained in standing stocks with the tail tied to prevent contamination of the operative field. Both flank regions are prepared for aseptic surgery. A sedative analgesic combination is administered. Local anesthesia of the trocar insertion sites is performed. Site for ovarian extraction is anticipated. Trocar positions can vary amoung the surgeons. We usually make the initial laparoscopic portal in the left flank for primary distension in order to avoid the base of the cecum. For right pathologic ovarian, the right flanc laparoscopic portal is performed after primary distension. Instrument portals are made after distension and under laparosopic control. We prefer to make the first instrument portal 7 cm ventral and slighly caudal to the laparoscopic portal and the second laparoscopic portal 7 cm ventral and slightly caudal to the first one. After a satisfactory examination of the target tissue has been accomplished, a laparoscopic needle is inserted through the dorsal instrument portal to infiltrate the dorsal mesovarian and mesosalpinx with 20 to 30 ml of 2% lidocaine. Whenever large or multiple cystic structures are evident, these structures should be aspirated using a laparoscopic needle to reduce the size and the weight of the ovary. This is best accomplished at the start of the procedure to improve access to the mesovarium and mesosalpynx. In granulosa cells tumors, the content of the liquid content is usually profuse, bloody and viscous. In this situation, a larger diameter laparoscopic needle connected to an aspirator can be useful. A grasping forceps is then introduced through this portal to grasp the mesosalpinx and place it under tension. The ligasure is then introduced through the ventral portal and used to divide the mesosalpinx of the oviduct. Traction is similarly applied on the ovarian to provide tension while the proper ligament is divided. Alternatively, dicision can be ashieved using bipolar electrocautery and/or sharp division using laparoscopic scissors as bleeding is usually minimal in this area. In very large ovarian, a close contact exists with the uterus, and various degrees of adhesion may exist. Strategic use of laparoscopic scissors may be necessary to prevent trauma to the uterus. In rare cases, other organ such as small colon might be also in contact or adhered to the medial part of the ovarian, and careful observation and repeated traction to the ovarian should be performed to prevent iatrogenic damage.
The ovarian is then suspended only by the mesovarium which contains a number of significant vascular structures. The ovarian is grasped with a laparoscopic Semm claw forceps introduced through the ventral portal. Hemostasis can be ashieved using double extracorporeal Roeder knot or modified Roeder knot or Ligasure . After double knotting, laparoscopic scissors are used to cut the mesovarium distal to the ligatures. Whatever the technique used, it is very important to perform the hemostasis while relaxing tension on the pedicle using the grasping forceps hold by the assistant, as the ovarian can be very heavy, leading to potential risk of tearing the vessels. In very large ovarian, it is sometimes advisable to start dissection at the dorsal mesovarium and let the ovarian progressively fall down to improve the access to the mesovarium. Hemostasis can also be performed using laparoscopic staples.
The free ovary is then suspended in the abdomen by the grasping forceps. Depending on ovary size, a number of techniques can be used to facilitate safe removal through the smallest possible abdominal incision. When standing flank extraction is chosen, I prefer to enlarge the ventral portal using a grid technique to about 8 to 10 cm. In very large ovaries, manual bagging or use of polypropylene band plastic retrieval bag (Wilderjans 2012) are the easiest way to remove very large ovary through small 8 cm incision. In the latter technique, an adhesive bag (one section adhesive bag, 48x38cm, Foliodrape® No. 258 322, Hartmann, Heidenheim, Germany) is fixed to a polypropylene band. The latter allows to open the bag within the abdomen without introducing the hand. Once the enlarged ovary is bagged, the opening of the bag is then pulled back through the incision site, completely isolating the ovary from the abdomen. An assistant can open the bag by pulling the edges of the bag apart, exposing a small part of the enlarged ovary. A combination of stab incisions in the ovary, sectionning of small pieces and aspiration allows to remove the ovary and the bag without contamination of the abdomen.
Another intersting technique we use to remove very large ovary is the two step procedure combining standing laparoscopic dissection and ovarian removal using a similar bagging technique through a small 8 cm ventral midline incision with the mare under general anesthesia. The ventral midline incision is a monolayer laparotomy, that allows easy introduction of the hand and drap positionning, and is faster to close. This technique is intersting to avoid scar tissue in the flank area especially in race or sport mares, to facilitate ovarian removal, and to manage concomittant adhesions between the ovary and uterus or bowel. In this situation, the incision can be easily enlarged and adhesion can be dissected under direct vision.