Equine laryngoplasty: Effects of three anchoring techniques in the muscular process and three positions for suture implantation in the cricoid cartilage.

OBJECTIVE: To compare the effects of three anchoring techniques in the muscular process and three positions of laryngoplasty suture implantation in the cricoid cartilage on abduction of the arytenoid cartilage and interaction with the cricoarytenoid dorsalis (CAD) muscle compartments. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Twenty-two cadaveric equine larynges. METHODS: Three implantation techniques were assessed in the left muscular process. They were the use of a titanium corkscrew (CS), a standard caudal passage using a Jamshidi needle (JCa), and a standard cranial passage using a Jamshidi needle (JCr). Each was assessed in combination with three caudal locations in the cricoid cartilage (right, left, and left lateral). Each suture combination was tightened to submaximal abduction (Dixon grade 2). Force on the suture, degree of larynx caudal rotation, and CAD muscle indentation were evaluated. RESULTS: The force required for optimal arytenoid cartilage abduction was lower (p < .01) for constructs involving a CS (7.45 ± 4 N). The CS also resulted in lower (p < .01) CAD muscle indentation (2.01 ± 1.25 mm) and less larynx rotation (9 ± 3.87°; adjusted p < .05). CONCLUSION: When inserted into the muscular process at the CAD tendon insertion point, the biomechanical properties of the CS reduced the force required for optimal arytenoid cartilage abduction. The CS also minimized interference with the CAD muscle compartments and reduced caudal displacement of the left arytenoid cartilage when it was under suture tension. CLINICAL SIGNIFICANCE: The CS implantation avoided larynx deformation and muscle interaction, offering the possibility to combine a nerve graft and laryngoplasty as a treatment for recurrent laryngeal neuropathy.

Balloon catheter occlusion of the maxillary, internal, and external carotid arteries in standing horses.

OBJECTIVE: To assess the feasibility of balloon catheter occlusion of the internal carotid artery (ICA), external carotid artery (ECA), and maxillary artery (MA) in standing horses. STUDY DESIGN: Experimental and clinical cases series. ANIMALS: Eight healthy horses (phase 1) and 11 clinical cases (phase 2). METHODS: Occlusions were performed on standing horses under sedation and local anesthesia. In phase 1, four horses underwent bilateral ICA balloon catheter occlusion, and four horses underwent balloon catheter occlusion of the ECA and MA. In phase 2, horses were treated by occlusion of ICA (n = 7), ECA (n = 2), or ECA and ICA (n = 2). RESULTS: Internal carotid artery occlusion was successful in seven of eight and seven of nine arteries in phases 1 and 2, respectively. The procedures lasted 53 and 50 minutes, respectively, and catheters were inserted over 13 ± 0.7 cm (mean ± SD). External carotid artery occlusion was successful in seven of seven and four of four arteries in phases 1 and 2, respectively, with mean durations of 31 and 26 minutes, respectively, and a mean distance of catheter insertion of 11.9 cm. Maxillary artery occlusion was successful in five of seven arteries (phase 1), with a mean surgical duration of 47 minutes and a mean distance of catheter insertion of 42.8 cm. CONCLUSION: Balloon catheter occlusion of the ICA, ECA, and MA was achieved in most standing horses. CLINICAL SIGNIFICANCE: Balloon catheter occlusion in standing horses provides an alternative to prevent or treat hemorrhage related to guttural pouch mycosis, particularly in horses in which general anesthesia might pose a risk.

Thyrohyoideus muscle innervation in the horse.

OBJECTIVE: To describe the innervation of the thyrohyoideus (TH) muscle and to confirm our findings with stimulation of first cervical (C1) nerve branches. STUDY DESIGN: Ex vivo phase 1 and clinical phase 2. ANIMALS: Fourteen head and neck specimens and 17 client-owned horses. METHODS: In phase 1, the cranial nerve (CN) XII and the C1 nerve were dissected with their branches in 20 dissections were performed on 14 specimens (6 left and right side and 8 only left or right) Anatomy was noted. Samples of nerve bifurcations were collected for histological confirmation of anatomical findings. First cervical nerve branches were stimulated in horses undergoing cervical nerve graft to treat laryngeal hemiplegia. RESULTS: The nerve innervating the TH muscle arose directly from the C1 nerve in 17 of 20 dissections, from an anastomotic branch between CN XII and the C1 nerve in two of 20 dissections, and from the C1 nerve and the anastomotic branch in one of 20 dissections. No direct connection between the TH muscle and CN XII was found. Histological examination revealed that the anastomosis was composed of C1 nerve fibers passing over to CN XII. First cervical stimulation resulted in TH muscle contraction in 16 of 17 horses. CONCLUSIONS: The innervation of the TH muscle originated from the C1 nerve according to dissection, histological, and conduction studies, with variation in the branching pattern. CLINICAL SIGNIFICANCE: Care should be taken to preserve the C1 nerve during prosthetic laryngoplasty. The surgical technique for C1 nerve grafts should be reconsidered in light of these findings, along with new options to treat dorsal displacement of the soft palate..

Self-Organization of Large Alumina Platelets and Silica Nanoparticles by Heteroaggregation and Sedimentation: Toward an Alternative Shaping of Nacre-Like Ceramic Composites.

Nacre-like ceramic composites are of importance in a wide range of applications, because of their mechanical properties, combining high mechanical strength and high fracture toughness. Those mechanical properties are the result of strongly aligned platelets glued in a matrix. Different methods exist to shape such a "brick-and-mortar" hierarchical structure. In this paper, we propose to use the phenomenon of heteroaggregation between silica nanoparticles and large alumina platelets. Experimental and numerical results show that silica nanoparticles can adsorb on alumina platelets with good distribution. This adsorption promotes the deagglomeration of alumina that can self-organize in layers by sedimentation. This phenomenon can be exploited to shape alumina-silica nacre-like composites.

Ex vivo study of minimally invasive procedures for cartilage removal from the metacarpophalangeal or metatarsophalangeal joint and for fetlock tension band application.

OBJECTIVE: To describe reliable minimally invasive procedures for (1) removing cartilage by joint distraction and articular drilling for equine metacarpophalangeal (MCP)/metatarsophalangeal (MTP) arthrodesis; (2) applying a palmar/plantar tension band without MCP/MTP joint luxation. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Cadaveric equine limbs (n = 12). METHODS: All limbs were used to evaluate the drilling technique. First the MCP/MTP joint was distracted with a 5.5-mm cortical screw. Then, through four stab incisions, articular cartilage was removed with a 4.5-mm drill. Six randomly chosen limbs were then tested for minimally invasive tension band application with a specially designed cannula. Accurate positioning of the tension band was assessed radiographically. All MCP/MTP joints were disarticulated, and the areas of removed cartilage were visually assessed and measured by using planimetry. RESULTS: The mean percentage of removed cartilage was 66.8% ± 7.6% for the metacarpus/metatarsus surface, 67.9% ± 8.6% for the proximal phalanx surface, and 59.5% ± 1% for the two sesamoid bones. The tension band could be accurately placed through four stab incisions with the cannula. CONCLUSION: This minimally invasive technique for cartilage removal was efficient and should be favorable for joint fusion in some clinical situations. The minimally invasive tension band application through stab incisions was feasible and repeatable. CLINICAL SIGNIFICANCE: These procedures should allow total minimally invasive MCP/MTP arthrodesis and be used in selected clinical cases.

Transendoscopic correction of epiglottic entrapment with a silicone-covered laser guide and diode laser in 29 horses.

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.

Standing MRI for surgical planning of equine fracture repair.

OBJECTIVE: To report the feasibility of standing MRI (sMRI) and document the value of sMRI in surgical planning for surgical repair of limb fractures in the horse. STUDY DESIGN: Retrospective case series. ANIMALS: Thirty-one horses with preoperative sMRI. METHODS: Medical records were reviewed for fracture type, application of a polyester cast, sMRI sequences performed, technical variables, and image quality. Fracture geometry and concomitant lesions were compared between sMRI and radiography. The relative value of sMRI with regard to surgical planning was classified as minor (sMRI did not provide additional findings), intermediate (additional lesions found or slight modification to surgical plan), or major (sMRI led to significant alternations in surgical plan). RESULTS: Standing MRI provided good studies in all horses. Standing MRI was classified as having major relevance in 12 of 31 horses, intermediate relevance in 14 of 31 horses, and minor relevance in 5 of 31 horses. CONCLUSION: Preoperative sMRI produced good studies in all horses and influenced the surgical planning in the majority of fractures in this study. Application of a polyester cast seemed to improve comfort without appreciable loss of image quality. CLINICAL SIGNIFICANCE: Standing MRI can be considered as an adjunct to plan the repair of equine fractures, and a polyester cast does not impair image quality.

Pancarpal and partial carpal arthrodesis with 3 locking compression plates in 6 horses.

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.

Anatomy of the vestibulum esophagi and surgical implications during prosthetic laryngoplasty in horses.

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.

Molecular Chemistry and Engineering of Boron-Modified Polyorganosilazanes as New Processable and Functional SiBCN Precursors.

A series of boron-modified polyorganosilazanes was synthesized from a poly(vinylmethyl-co-methyl)silazane and controlled amounts of borane dimethyl sulfide. The role of the chemistry behind their synthesis has been studied in detail by using solid-state NMR spectroscopy, FTIR spectroscopy, and elemental analysis. The intimate relationship between the chemistry and the processability of these polymers is discussed. Polymers with low boron contents displayed appropriate requirements for facile processing in solution, such as impregnation of host carbon materials, which resulted in the design of mesoporous monoliths with a high specific surface area after pyrolysis. Polymers with high boron content are more appropriate for solid-state processing to design mechanically robust monolith-type macroporous and dense structures after pyrolysis. Boron acts as a crosslinking element, which offers the possibility to extend the processability of polyorganosilazanes and suppress the distillation of oligomeric fragments in the low-temperature region of their thermal decomposition (i.e., pyrolysis) at 1000 °C under nitrogen. Polymers with controlled and high ceramic yields were generated. We provide a comprehensive mechanistic study of the two-step thermal decomposition based on a combination of thermogravimetric experiments coupled with elemental analysis, solid-state NMR spectroscopy, and FTIR spectroscopy. Selected characterization tools allowed the investigation of specific properties of the monolith-type SiBCN materials.

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.

Internal Fixation of Cervical Fractures in Three Horses.

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.

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.

Use of a modified transfixation pin cast for treatment of comminuted phalangeal fractures in horses.

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.

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.

Use of Knotless Barbed Sutures in Laparoscopic Inguinal Hernioplasty in Horses: 40 Cases.

Inguinal hernias (IHs) and ruptures are a relatively common condition in horses, occurring in foals (congenital) and adult (acquired) animals. A retrospective observational analysis was conducted on 40 cases that underwent laparoscopic surgery to close the VRs using barbed sutures alone or combined with other techniques. Signalment, clinical presentation, surgery, and follow-up data were obtained. In total, fifty-nine VRs were closed using barbed sutures (alone or in combination with other methods), with six cases performed prophylactically and forty-four due to acquired IH. Of the forty-four cases with IH, four were non-strangulated hernias, while thirty presented with strangulated small intestines (twenty-eight acquired and two congenital). The results obtained in this study suggest that laparoscopic hernioplasty with barbed sutures is an effective and safe surgical procedure that could be recommended as a standard practice for managing inguinal hernias in horses, particularly when sparing testicles or preserving reproductive capabilities is a priority.

Laryngeal reinnervation using the spinal accessory nerve: Electromyographic study of the sternomandibularis muscle.

BACKGROUND: Selective laryngeal reinnervation using the first and second cervical nerve (C1C2) is a treatment option for recurrent laryngeal neuropathy that aims to restore the function of the cricoarytenoideus dorsalis (CAD) muscle. Despite the technique's satisfying success rate, it has several limitations. These triggered the search for another potential donor nerve that could reduce CAD muscle fatigue and shorten rehabilitation. The ventral branch of the spinal accessory nerve, providing motor innervation to the sternomandibularis (SM) muscle, was identified as a potentially well-adapted nerve. OBJECTIVES: To gather normative data from SM muscle activity induced by physiological spinal accessory nerve stimulation at rest and during exercise, and to determine SM muscle activity and fibre type recruitment relative to posture, gait and respiratory cycle. STUDY DESIGN: Clinical observational study. METHODS: Surface electromyography (EMG) of the SM muscle was performed in nine horses: trained warmbloods, Thoroughbreds and Standardbreds. Signals were recorded in different feeding postures and at exercise, which included standardised treadmill exercise tests, lungeing and ridden work. RESULTS: Timing of the SM muscle contraction coincided with inspiration at gallop. Intra-individual mean SM muscle activity increased with exercising speed (four times higher in Thoroughbreds at gallop than walk and seven times higher in Standardbreds at high-speed trot than walk). Moreover, the SM muscle was strongly activated at rest when the horse was grazing (seven times more than when it was eating out of a hay net or stable feeder). Frequency domain analysis revealed a predominant type I muscle fibre recruitment during feeding and at exercise (type I muscle fibre activity was at least 2.5 times higher than type II muscle fibre activity). MAIN LIMITATIONS: Lack of reference data on equine EMG. CONCLUSIONS: This study confirmed the potentially advantageous properties of the spinal accessory nerve for laryngeal reinnervation.

Holographic photopolymerization combined to microfluidics for the fabrication of lab-in-lab microdevices and complex 3D micro-objects.

We show here brand-new possibilities of lab-in-lab fabrication while combining holographic photopolymerization and microfluidics. One shot real-time 3D-printing can produce 3D architectured microchannels, or free-standing complex micro-objects eventually in flow. The methodology is very versatile and can be applied to e.g., acrylate resins or hydrogels.