Ex vivo biomechanical stability of 5 cricoid-suture constructs for equine laryngoplasty.

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.

Mechanical comparison of 3 anchoring techniques in the muscular process for laryngoplasty in the equine larynx.

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.

Laryngoplasty in standing horses.

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.

Standing laparoscopic inguinal hernioplasty using cyanoacrylate for preventing recurrence of acquired strangulated inguinal herniation in 10 stallions.

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.

Two-step surgery combining standing laparoscopy with recumbent ventral median celiotomy for removal of enlarged pathologic ovaries in 20 mares.

OBJECTIVES: To report a combination of standing laparoscopic technique for intra-abdominal dissection of the mesovarial pedicle followed by a limited ventral median celiotomy under general anesthesia for removal of enlarged ovaries in mares. STUDY DESIGN: Case series. ANIMALS: Mares (n = 20) aged 3-22 years with unilateral enlarged ovaries. METHODS: Enlarged ovaries were confirmed by transrectal palpation and ultrasonography. After sedation, 3 laparoscopic portals were made in the paralumbar fossa. The mesovarium was desensitized and dissected using a vessel sealing device, and the ovary was left free in the abdomen. Then under general anesthesia, the mare was positioned in dorsal recumbency and an 8 cm ventral median celiotomy made for ovary retrieval in a specimen bag. RESULTS: This 2-step procedure was successfully used for removal enlarged ovaries (12-50 cm) in 17 mares and for management of behavioral problems in 3 mares. No operative or postoperative complications occurred. Owner satisfaction and cosmesis were considered excellent. CONCLUSIONS: Standing laparoscopy combined with a limited median celiotomy is a safe technique for ovariectomy in mares. This technique mitigates most of the disadvantages of standing flank ovariectomy and a conventional open ventral median approach.

An Extra-Articular Surgical Approach to Subchondral Bone Cysts in the Humeral Head and Talus in Two Horses.

To date, only a few reports describe the treatment. The present report describes an extraarticular surgical approach, with the insertion of an absorbable implant, to treat a Subchondral cystic lesion (SCL) in the humeral head 3year old racing Thoroughbred & in the talus of a 11year old Arabian horse. SCLs were radiographically visible and associated with severe lameness. Scintigraphy showed focal intense radiopharmaceutical uptake in both cases, and CT scan revealed signs of osteoarthrosis associated with SCL in the talus. The use of a biocompatible, osteoinductive and osteoconductive implant allowed a reduction of the SCL radiographic appearance of at least 70% in both cases and horses returned to their previous athletic activity. The results of the present study might provide substantial information about a new surgical option to treat SCLs in the scapulohumeral and tarsocrural joints and may broaden prognosis and prolong future athletic ability of affected horses.

A composite absorbable implant used to treat subchondral bone cysts in 38 horses.

BACKGROUND: In the last 30 years, several treatments have been proposed to treat subchondral cystic lesions (SCLs) but there have been no randomised studies to compare different methods and there is no consensus as to the optimal treatment. OBJECTIVES: To evaluate a biocompatible absorbable implant for the treatment of SCLs in young horses in different anatomical locations. STUDY DESIGN: Retrospective case series. METHODS: Horses with SCLs were treated with debridement through a trans-cortical extra-articular approach and an absorbable implant was inserted in the cavity. Clinical and radiographic follow-up was recorded and follow up ranged from 28 to 46 months (mean 37 months). Racing records were reviewed. RESULTS: Thirty-eight horses between 10 and 24 months of age were included in the study. In 36 of 38 horses treated, lameness resolved, and 77% average filling of the cyst was measured 120 days after surgery on radiographs. In two cases, surgical complications were recorded. MAIN LIMITATIONS: Information about the resorption of the implant is not available. Radiographs were performed in various hospitals or at farms or training stables, therefore, possible minor variations in technique and positioning occurred. CONCLUSIONS: The extra-articular approach to the SCLs followed by the insertion of the absorbable implant led to clinical and radiographic improvement of the SCLs at 120 days after surgery. This technique, feasible in different anatomical locations, may offer an alternative to treat SCLs in young horses.

Comparison of Serum Amyloid A Measurements in Equine Synovial Fluid With Routine Diagnostic Methods to Detect Synovial Infection in a Clinical Environment.

Synovial fluid analysis is utilized to diagnose septic synovitis. However, not all cases are clearly and rapidly discernible with the diagnostic tools available in the laboratory. Serum amyloid A (SAA), an acute phase protein, has been shown to be elevated in synovial fluid from inflamed synovial structures. The goal of this study is to describe the correlation between two diagnostic tests measuring equine SAA levels in septic and non-septic synovial structures and to understand the correlation between an elevated SAA result and synovial sepsis. Prospective estimation of sensitivity (Se) and specificity (Sp) of two tests, handheld and ELISA, measuring SAA in synovial fluid was completed in 62 horses presented with injured synovial structures. The comparison was made to a reference diagnosis based on white cell count, percentage of neutrophils, intracellular bacteria and bacterial culture on synovial fluid. Handheld test levels were classified as: 4 lines visible-SAA level negative; 3 lines visible-SAA level mild; 2 lines visible-SAA level moderate; and 1 line visible-SAA level severe and compared to the numerical value obtained with ELISA test. The ELISA SAA test had an area under the curve of 0.88 (0.78-0.98). An ELISA cut-off of 23.95 µg/mL maximized Se and Sp. This cutoff gave a Se of 0.93 (0.66-1.00) and Sp of 0.77 (0.63-0.88). The handheld test was highly correlated with the ELISA SAA test (Spearman rank correlation 0.96) and at a cutoff of moderate or higher for positive results gave identical Se and Sp. Se and Sp of synovial fluid SAA are very reliable when clinical signs of synovitis are present for >6 h. This test, in conjunction with traditional methods, can assist practitioners to rapidly diagnose and expedite appropriate intervention of synovial sepsis.

Comparison of efficacy and safety of single versus repeated intra-articular injection of allogeneic neonatal mesenchymal stem cells for treatment of osteoarthritis of the metacarpophalangeal/metatarsophalangeal joint in horses: A clinical pilot study.

The purpose of this prospective study was to evaluate the effects of single and repeated intra-articular administration of allogeneic, umbilical cord-derived, neonatal mesenchymal stem cells (MSC) in horses with lameness due to osteoarthritis (OA) of a metacarpophalangeal joint (MPJ). Twenty-eight horses were included. Horses were divided into two groups. Horses in group MSC1 received an MSC injection at M0 and a placebo injection at M1 (1 month after M0). Horses in group MSC2 received MSC injections at M0 and at M1. Joint injections were performed with a blinded syringe. Clinical assessment was performed by the treating veterinarian at M1, M2 and M6 (2 and 6 months after M0), including lameness evaluation, palpation and flexion of the joint. Radiographic examination of the treated joints was performed at inclusion and repeated at M6. Radiographs were anonymized and assessed by 2 ECVDI LA associate members. Short term safety assessment was performed by owner survey. A 2-month rehabilitation program was recommended to veterinarians. There was a significant improvement of the total clinical score for horses in both groups. There was no significant difference in the total clinical score between groups MSC1 and MSC2 at any time point in the study. There was no significant difference in the total radiographic OA score, osteophyte score, joint space width score and subchondral bone score between inclusion and M6. Owner-detected adverse effects to MSC injection were recorded in 18% of the horses. Lameness caused by OA improved significantly over the 6-month duration of the study after treatment with allogeneic neonatal umbilical cord-derived MSCs combined with 8 weeks rest and rehabilitation. There is no apparent clinical benefit of repeated intra-articular administration of MSCs at a 1-month interval in horses with MPJ OA when compared to the effect of a single injection.