Dorsal-to-palmar branch neuroanastomosis in horses undergoing palmar digital neurectomy does not reduce neuroma formation or improve outcome.

OBJECTIVE: Chronic foot pain, a common cause of forelimb lameness, can be treated by palmar digital neurectomy (PDN). Complications include neuroma formation and lameness recurrence. In humans, neuroanastomoses are performed to prevent neuroma formation. The aim of the study was to evaluate the outcome of horses undergoing dorsal-to-palmar branch neuroanastomosis following PDN. STUDY DESIGN: Retrospective case series. ANIMALS: Eighty-five horses with PDN and dorsal-to-palmar branch neuroanastomosis. METHODS: Medical records for horses undergoing this procedure at two hospitals between 2015 and 2020 were reviewed. Palmar and dorsal nerve branches of the PDN were transected and end-to-end neuroanastomosis was performed by apposition of the perineurium. Follow-up was obtained from medical records and telephone interviews. Success was defined as resolution of lameness for at least one year. RESULTS: Lameness resolved following surgery in 81/85 (95%) horses with 57/84 (68%) sound at one year. Postoperative complications occurred in 19/85 (22%) cases. The main limitations of the study were an incomplete data set, inaccurate owner recall, and variations in procedure. CONCLUSION: Compared to previous studies, this technique resulted in similar numbers of horses sound immediately after surgery, a comparable rate of postoperative neuroma formation but a higher recurrence of lameness rate at 1 year postoperatively. CLINICAL SIGNIFICANCE: End-to-end neuroanastomosis of the dorsal and palmar branches of the PDN does not reduce the rate of neuroma formation in horses. Long-term outcome was less favorable compared to previously reported PDN techniques.

Application accuracy of a frameless optical neuronavigation system as a guide for craniotomies in dogs.

BACKGROUND: Optical neuronavigation systems using infrared light to create a virtual reality image of the brain allow the surgeon to track instruments in real time. Due to the high vulnerability of the brain, neurosurgical interventions must be performed with a high precision. The aim of the experimental cadaveric study was to determine the application accuracy of a frameless optical neuronavigation system as guide for craniotomies by determining the target point deviation of predefined target points at the skull surface in the area of access to the cerebrum, cerebellum and the pituitary fossa. On each of the five canine cadaver heads ten target points were marked in a preoperative computed tomography (CT) scan. These target points were found on the cadaver skulls using the optical neuronavigation system. Then a small drill hole (1.5 mm) was drilled at these points. Subsequently, another CT scan was made. Both CT data sets were fused into the neuronavigation software, and the actual target point coordinates were identified. The target point deviation was determined as the difference between the planned and drilled target point coordinates. The calculated deviation was compared between two observers. RESULTS: The analysis of the target point accuracies of all dogs in both observers taken together showed a median target point deviation of 1.57 mm (range: 0.42 to 5.14 mm). No significant differences were found between the observers or the different areas of target regions. CONCLUSION: The application accuracy of the described system is similar to the accuracy of other optical neuronavigation systems previously described in veterinary medicine, in which mean values of 1.79 to 4.3 mm and median target point deviations of 0.79 to 3.53 mm were determined.

Use of a telovelar approach for complete resection of a choroid plexus tumor in a dog.

OBJECTIVE: To describe a telovelar approach to the fourth ventricle for excision of a choroid plexus tumor within the ventricle. ANIMAL: A 3-year-old entire male Chihuahua. STUDY DESIGN: Case report METHODS: A 3-year-old dog with two-month history of progressive vestibular signs and subdued mentation was diagnosed with a fourth ventricle tumor. Gross total resection of the tumor was achieved through a telovelar approach to the fourth ventricle. RESULTS: Complete removal of the tumor was confirmed on immediate postoperative MRI. The dog recovered from the surgical procedure without complications, displaying some neurological deficits as preoperatively. His neurological examination was normal 2 weeks after surgery and remained so until the time of writing this case report (28 months) without additional treatment. CONCLUSION: The telovelar approach allowed complete excision of a choroid plexus tumor located in the fourth ventricle of the dog reported here.

Cystoscopic Abnormalities in Dogs Presented for Episioplasty.

A recessed vulva is a conformational abnormality that predisposes affected dogs to urinary tract infections. An episioplasty can be recommended for correction of this abnormality when medical management of recurrent urinary tract infection fails. The objective of this study was to investigate the type and incidence of urogenital abnormalities visualized by cystoscopy in dogs presenting for episioplasty. Medical records of 29 dogs that presented for an episioplasty and had a concurrent or prior cystoscopy were reviewed. Eleven of the 29 dogs had urogenital abnormalities diagnosed on cystoscopic evaluation, and 1 dog was diagnosed with a urogenital abnormality during vaginal examination while under general anesthesia. Ten of the dogs with urogenital abnormalities had a corrective procedure performed, 8 of which were cystoscopically assisted. Cystoscopy provides the ability to directly visualize the urinary tract and obtain samples for biopsy and culture and facilitates correction of some anatomic abnormalities that may predispose the patient to developing recurrent urinary tract infections. Cystoscopy should be considered as a routine part of a thorough evaluation of the urinary tract in cases presenting for episioplasty.

Influence of crotch suture augmentation on leakage pressure and leakage location during functional end-to-end stapled anastomoses in dogs.

OBJECTIVE: To determine the influence of anastomotic crotch suture augmentation on leakage pressures and leakage location following intestinal functional end-to-end stapled anastomosis (FEESA) in dogs. STUDY DESIGN: Ex vivo, randomized, experimental. SAMPLE POPULATION: Chilled jejunal segments from 3 adult dogs. METHODS: Jejunal specimens were tested within 24 hours of collection. A FEESA was performed and randomly assigned to 1 of 4 treatment groups (n = 12/group): (1) no crotch suture (NCS); (2) simple interrupted crotch suture (SICS); (3) two simple interrupted crotch sutures (TCS) placed laterally on opposing jejunal limbs; (4) simple continuous crotch suture (SCCS) augmentation. Crotch sutures were performed using 3-0 USP polydioxanone. Initial (ILP) and maximal (MLP) leakage pressures (Mean ± SD mm Hg) and leakage location were recorded and compared between groups. RESULTS: Initial leakage pressure was greater after placement of TCS (37.8 ± 6.4, P < .039) and SCCS (47.6 ± 11.0, P < .002) than NCS (27.1 ± 2.5) and SICS (33.0 ± 6.0). Maximal leakage pressure was greater in specimens including SICS, TCS, and SCCS than those without crotch suture augmentation (P < .043). Leakage occurred at the anastomotic crotch in 8/12 NCS, 6/12 SICS, 11/12 TCS, and 12/12 SCCS constructs (P < .001). CONCLUSION: Augmentation of FEESA with TCS and SCCS increased ILP and decreased the occurrence of leakage from the anastomotic crotch, while all methods of anastomotic crotch augmentation increased MLP. CLINICAL SIGNIFICANCE: Augmenting the FEESA with crotch suture(s) improved the resistance of the jejunal anastomosis to leakage in normal cadaveric segments. Placing 2 crotch sutures or use of a simple continuous pattern for anastomotic augmentation appeared to be superior to the placement of a single suture.

Real-time analysis of intraoperative delays and variations in intraoperative workflow with level of experience of the primary surgeon in small animal surgery.

OBJECTIVE: To describe the causes of intraoperative delays and the changes in delays and surgical workflow with the level of training of the primary surgeon. STUDY DESIGN: Prospective observational study. SAMPLE POPULATION: Seventy-three small animal surgical procedures performed at an academic teaching institution between January 17, 2018 and April 10, 2018. METHODS: Procedures (trainee = 37, faculty = 36) totaling 103.2 h were observed and video recorded. Operative time was allocated to the surgical approach, exploration, exposure, intervention, and closure phases. Suballocations were made to specific tasks within these categories (such as cutting or hemostasis). Intraoperative delays and reasons were recorded. Differences in use of time between trainee and faculty surgeons were analyzed. RESULTS: Delays constituted 9.2% (±4.4) of the operative time, of which 6.5%(±3.6) were surgeon controlled and 2.6% (±2.7) were non-surgeon controlled. Surgeons preparing instrumentation outside of the operative field and retrieval of equipment from supply areas were the greatest contributors to delays. Intraoperative delays did not increase when the trainee was placed in the primary surgeon role (P = .78). During the approach faculty surgeons spent proportionally less time on hemostasis (P = .02), and during closure they spent less time suturing (P = .03) than trainees. CONCLUSION: Trainee surgeons did not have greater intraoperative delays. Delays were created when surgeons prepared their own instrumentation. Workflow differed between experts and trainees. CLINICAL SIGNIFICANCE: Advancing a trainee surgeon into the primary role is unlikely to increase intraoperative delays, which can be reduced by the inclusion of trained scrub technicians. A focus on efficient hemostasis and fluidity when suturing may improve operative efficiency for surgical trainees.

Antimicrobial prophylaxis is considered sufficient to preserve an acceptable surgical site infection rate in clean orthopaedic and neurosurgeries in dogs.

BACKGROUND: Surgical site infections (SSI) are associated with increased morbidity and mortality. To lower the incidence of SSI, antimicrobial prophylaxis is given 30-60 min before certain types of surgeries in both human and veterinary patients. However, due to the increasing concern of antimicrobial resistance, the benefit of antimicrobial prophylaxis in clean orthopaedic and neurosurgeries warrants investigation. The aims of this retrospective cross-sectional study were to review the rate of SSI and evaluate the compliance with antimicrobial guidelines in dogs at a veterinary teaching hospital in 2012-2016. In addition, possible risk factors for SSI were assessed. RESULTS: Nearly all dogs (377/406; 92.9%) received antimicrobial prophylaxis. Twenty-nine dogs (7.1%) did not receive any antimicrobials and only four (1.1%) received postoperative antimicrobials. The compliance with in-house and national protocols was excellent regarding the choice of prophylactic antimicrobial (cefazolin), but there was room for improvement in the timing of prophylaxis administration. Follow-up data was available for 89.4% (363/406) of the dogs. Mean follow-up time was 464 days (range: 3-2600 days). The overall SSI rate was 6.3%: in orthopaedic surgeries it was 6.7%, and in neurosurgeries it was 4.2%. The lowest SSI rates (0%) were seen in extracapsular repair of cranial cruciate ligament rupture, ulnar ostectomy, femoral head and neck excision, arthrotomy and coxofemoral luxation repair. The highest SSI rate (25.0%) was seen in arthrodesis. Omission of antimicrobials did not increase the risk for SSI (P = 0.56; OR 1.7; CI95% 0.4-5.0). Several risk factors for SSI were identified, including methicillin-resistant Staphylococcus pseudintermedius carriage (P = 0.02; OR 9.0; CI95% 1.4-57.9) and higher body temperature (P = 0.03; OR 1.69; CI95% 1.0-2.7; mean difference + 0.4 °C compared to dogs without SSI). CONCLUSIONS: Antimicrobial prophylaxis without postoperative antimicrobials is sufficient to maintain the overall rate of SSI at a level similar to published data in canine clean orthopedic and neurosurgeries.

Transorbital postcaruncular endoscopic surgery as an alternative to orbital exploratory surgery: A cadaveric study and case report in a dog with an orbital sarcoma.

OBJECTIVE: To describe a postcaruncular approach for transorbital endoscopy as an alternative, minimally invasive technique to access the orbital apex. STUDY DESIGN: Ex vivo and prospective clinical case report. ANIMALS: A 12-year-old male castrated cocker spaniel and three cadaver heads (one large breed dolichocephalic, one medium-sized breed mesocephalic, and one small breed brachycephalic). METHODS: Transorbital endoscopy was performed to obtain biopsies of an orbital apex mass by using a postcaruncular approach. A 2.7-mm 30° rigid endoscope fitted with a cystoscope working sheath was used with the aid of a blunt suction-dissector and fluid ingress. This procedure was first performed on three cadavers to assess feasibility and later performed in a clinical case. RESULTS: By using a transorbital postcaruncular approach, it was possible to visualize and obtain biopsies from structures within the orbital apex with minimal perioperative morbidity. Dissection and expansion of the working space was facilitated with the aid of fluid ingress; however, judicious use of fluids is recommended because secondary orbital edema and chemosis can occur. CONCLUSION: Transorbital endoscopy via a postcaruncular approach is feasible. CLINICAL SIGNIFICANCE: This technique should be considered in cases in which a histological diagnosis is required prior to definitive treatment as a method to obtain biopsy samples of the orbital apex region without major surgical dissection.

Use of a bipolar sealing device to seal partial cystectomy with and without augmentation with a single-layer simple continuous suture pattern in an ex vivo canine model.

OBJECTIVE: To evaluate the ability of a bipolar sealing device (BSD) to seal canine bladder tissue and to determine the influence of suture augmentation on resistance to leakage of sealed partial cystectomies. STUDY DESIGN: Ex vivo, simple randomized study. SAMPLE POPULATION: Urinary bladders harvested from canine cadavers (n = 23). METHODS: Partial cystectomy of the cranial third of each bladder was performed with a BSD. This seal was augmented with a simple continuous pattern of 4-0 polydioxanone in half of the specimens. A pressure transducer inserted through the ureter measured intraluminal pressure at initial leakage and catastrophic failure as dyed saline was infused via a catheter inserted through the urethra. Initial leakage pressure and pressure at catastrophic failure were compared between sutured and nonsutured sealed partial cystectomies. RESULTS: Sutured sealed cystectomies showed initial leakage at lower pressures compared to non-sutured cystectomies (8.6 vs. 17.7 mm Hg; P = .0365) but were able to sustain greater pressures at catastrophic failure (34.3 vs. 21.8 mm Hg; P = .007). Catastrophic failure occurred along the seam of all nonsutured sealed cystectomies and at the suture holes in 10 of the 12 sutured bladders. CONCLUSION: Partial cystectomies were effectively sealed with a BSD in this canine cadaveric bladder model. Augmentation with a simple continuous suture pattern increased the pressure at which catastrophic leakage occurred but lowered initial leak pressure. CLINICAL SIGNIFICANCE: This study provides evidence supporting the evaluation of BSD use for partial cystectomy in live animals.

Minimally invasive microsurgical decompression of an intervertebral disc protrusion in a dog.

OBJECTIVE: To report the successful treatment of intervertebral disc protrusion with minimally invasive microsurgery in a large breed dog. STUDY DESIGN: Retrospective case report. ANIMAL: A 4-year-old, neutered male, German shepherd dog presented with chronic progressive ambulatory paraparesis and thoracolumbar pain; lumbar intervertebral disc protrusion and severe spinal cord compression at L2-L3 were diagnosed. METHODS: A minimally invasive approach was used to access the target surgical area by using a muscle splitting technique and retractors. Intraoperative fluoroscopy confirmed correct placement. Magnification and illumination through a surgical microscope were used (microsurgery) to perform the spinal cord decompression by means of a foraminotomy and lateral corpectomy. RESULTS: Technically, the combination of fluoroscopy and muscle splitting approach offered adequate minimally invasive access. Microsurgery allowed for precise and efficient spinal cord decompression. Clinically, no immediate postoperative neurological deterioration was observed. Opioid usage was limited to 24 hours postoperatively. Focal muscle swelling was observed postoperatively for 2 days, and hospital stay was 3 days. At 7 weeks postoperatively, neurological examination results were normal, and postoperative MRI confirmed spinal cord decompression. No complications were reported. CONCLUSION: The procedure was associated with a small incision, limited muscle trauma, early improvement of the neurological status, a short hospital stay, and limited postoperative pain. CLINICAL SIGNIFICANCE: This case provides evidence that minimally invasive microsurgery is an effective treatment for intervertebral disc protrusion in large breed dogs and may offer benefits regarding postoperative pain and functional recovery.

Visualization of Trigeminal Ganglion Neuronal Activities in Mice.

Visualization of dynamic cellular activity has greatly expanded our understanding of brain function. Recently, there has been an increasing number of studies imaging rodent brain activity in real time. However, traditional in vivo calcium imaging technology has been limited to superficial brain structures. Because the trigeminal ganglion (TG) is located deep within the cranial cavity of mice, few studies have been able to access to it. To circumvent this limitation, overlying brain tissue must be removed to expose the TG so that optical recording can access deep brain neural ensembles. This unit describes a procedure for conducting non-survival surgery to visualize the TG in live mice. Obtaining large ensembles of direct, real-time readouts of sensory neuron signaling, providing temporal and spatial information across the TG, will help to define the cellular basis of orofacial somatic sensing and pain perception. © 2019 by John Wiley & Sons, Inc.

Nerve Stimulator-guided Injection of Autologous Stem Cells Near the Equine Left Recurrent Laryngeal Nerve.

Recurrent laryngeal neuropathy (RLN) commonly affects horses and is characterized by abnormal respiratory sounds and exercise intolerance. The recurrent laryngeal nerve shows lesions of demyelination. The benefit of applying stem cells to demyelinated nerves has been demonstrated in various animal models. The aim of the study was to test the feasibility and safety of a peri-neuronal injection of autologous muscle-derived mesenchymal stem cells to the left recurrent laryngeal nerve in healthy horses by using an electrical nerve stimulator. Muscle-derived stems cell are obtained from five healthy Standardbred horses by sampling 20 mg of muscle tissue with a semi-automatic 14 G biopsy needle from the triceps muscle. Movements of the larynx are monitored via upper-airway video endoscopy. The left recurrent laryngeal nerve is approached with an insulated nerve block needle. Nerve stimulation is applied, starting at 2 mA, and the successful abduction of the left arytenoid is monitored. The stimulation intensity is reduced progressively. When a loss of the motor response is observed at 0.5 mA, 107 autologous muscle-derived stem cells are injected. Two examiners, who are blinded to the time point, score the laryngeal function of the horses prior to the treatment and at day 1, day 7, and day 28 after the injection of the cells. In a sixth horse, 1 mL of 2% lidocaine is injected to further confirm the correct positioning of the needle. This leads to a temporary paralysis of the left arytenoid cartilage. This study proves that the recurrent laryngeal nerve can be approached with the help of an electrical nerve stimulator and that the electrical stimulation of the nerve is well tolerated by the horses. No modification of the laryngeal function was observed in any of the horses after the injection of the stem cells. Further studies should be conducted to describe the effects of a peri-neuronal injection of autologous muscle-derived mesenchymal stem cells to horses suffering from RLN.

Minimally Invasive Spine Surgery in Small Animals.

Minimally invasive spine surgery (MISS) seems to have many benefits for human patients and is currently used for various minor and major spine procedures. For MISS, a change in access strategy to the target location is necessary and it requires intraoperative imaging, special instrumentation, and magnification. Few veterinary studies have evaluated MISS for canine patients for spinal decompression procedures. This article discusses the general requirements for MISS and how these can be applied to veterinary spinal surgery. The current veterinary MISS literature is reviewed and suggestions are made on how to apply MISS to different spinal locations.

Placement of vertebral screws for spinal stabilization and distraction in a dog with disc-associate cervical spondylomyelopathy: case report / Uso de parafusos vertebrais para distração e estabilização espinhal em um cão com espondilomielopatia cervical disco-associada: relato de caso

A 10-year-old male Rottweiler was evaluated for a 2-month history of recurrent forelimb weakness. Neurologic examination revealed proprioceptive ataxia, tetraparesis and moderate cervical pain. Disk-associated cervical spondylomyelopathy (CSM) with static lesion at C3-4 was diagnosed based on magnetic resonance imaging (MRI). The dog was surgically treated by a ventral slot procedure and distraction-stabilization of the vertebral bodies through insertion of vertebral screws with transverse connective bars. The patient had favorable clinical outcome. Neurologic assessment performed 120 days after surgery showed absence of neurologic defects. Radiographic assessment performed at the same time indicated adequate spinal cord decompression although vertebral fusion was not achieved. To the authors' knowledge, this is the first case of distraction-stabilization with vertebral (pedicle) screws to treat CSM in a dog. The treatment was well tolerated with no complications and excellent outcome and can be a viable option for this condition.(AU)

Um cão, macho, adulto, Rotweiller de 10 anos de idade, foi atendido com histórico de claudicação do membro torácico esquerdo com evolução para fraqueza havia aproximadamente dois meses. Ao exame neurológico, observou-se ataxia proprioceptiva nos quatro membros e dor cervical moderada. Mediante ressonância magnética, espondilomielopatia cervical disco-associada com a característica estática da compressão C3-C4 foi diagnosticada. Realizou-se cirurgia descompressiva por meio de slot ventral e estabilização-distração com o uso de parafusos vertebrais e barras conectoras. O paciente apresentou evolução clínica favorável do quadro. A evolução foi progressiva e, no último retorno, 120 dias após a cirurgia, não apresentou nenhum déficit neurológico ou sinal de falha do implante nas imagens radiográficas; no entanto, não foi evidenciada fusão vertebral. Pelo conhecimento dos autores, esse é o primeiro relato de EMC disco-associada tratada por distração e estabilização com parafusos vertebrais (pediculares) em um cão. A fixação espinhal por meio do uso de parafusos vertebrais foi uma alternativa viável no caso apresentado.(AU)

Magnetic Resonance Imaging Appearance and Mechanism of Action of Five Hemostatic Agents Used in Neurosurgery.

OBJECTIVE: To describe the magnetic resonance (MR) image appearance of 5 hemostatic agents placed in the brain, and to review their clinical application. STUDY DESIGN: Descriptive ex vivo and in vivo study. ANIMALS: Canine cadavers (n=4), client-owned dogs (n=4). METHODS: Heads from 4 canine cadavers were used, each with 5 hemostatic agents placed in specific locations in the brain. Hemostatic agents were used in their native form in 2 cadaveric brains, and in 2 others the materials were saturated with fresh whole blood prior to placement to mimic application in a field of active hemorrhage. The heads underwent MR imaging and the images were reviewed. Postoperative MRI images from 4 dogs undergoing brain tumor resection were retrospectively reviewed and compared to the images from the cadavers. All clinical cases and cadaveric specimens underwent surgical closure prior to MR imaging including placement of titanium mesh over the craniotomy defect with a dural graft of porcine small intestinal submucosa (SIS) sealed with Tisseel (fibrin sealant). RESULTS: The SIS and Tisseel used in the dural graft were consistently indistinguishable from the surrounding tissues on MR images. The MR imaging appearance of the remaining 4 hemostatic agents (Gelfoam, Avitene, Surgicel, and Floseal) placed on the surface or in the parenchyma of canine brain, varied with MR sequence weighting and blood saturation. CONCLUSION: Accurate evaluation of the degree of brain tumor resection on postoperative MR images requires careful differentiation between hemorrhage, residual tumor, and hemostatic agents implanted.

Side to side coaptation--new technic in peripherial nerve surgery--preliminary report.

This study presents and evaluates side-to-side nerve repair techniques for their ability to induce collateral nerve sprouting. The coaptation of the ventral branches of spinal nerves C5 and C6 to C7 through an incision epineurium was used to repair the nerve. The number of myelinated fiber axons and G-ratio was evaluated. Preliminary results indicate the possibility of using side to side coaptation in brachial plexus nerve surgery.

Long Term Outcome of Conservative Management or Surgical Treatment of Bovine Spastic Paresis: 79 Cases.

OBJECTIVE: To report the long term clinical outcome of calves treated surgically or managed conservatively for bovine spastic paresis of the gastrocnemius (BSP-G), quadriceps femoris muscle (BSP-Q), or mixed muscle involvement (BSP-M). STUDY DESIGN: Retrospective case study. ANIMALS: Calves (n = 79) with bovine spastic paresis. METHODS: Medical records of calves treated by partial tibial neurectomy or managed conservatively for bovine spastic paresis were analyzed for sex, breed, lineage history, and the onset, duration, and severity of clinical signs. Cases were classified as unilateral or bilateral BSP-G, BSP-Q, or BSP-M. Long term follow-up information was obtained by telephone questionnaire. RESULTS: The study group included 26 BSP-G (33%), 16 BSP-Q (20%), and 37 BSP-M (47%) calves. BSP-M and BSP-Q calves were significantly more bilaterally affected compared to BSP-G calves. Twenty-five of 26 BSP-G calves were treated surgically; 86% had complete resolution of clinical signs. Twenty-nine of 37 BSP-M calves were treated surgically; 81.5% improved, but none completely recovered. In all of the conservatively managed BSP-M calves, clinical signs gradually worsened. None of the BSP-Q calves were treated surgically; in 66.7%, clinical signs gradually worsened and 33.3% of calves spontaneously improved. CONCLUSION: Partial tibial neurectomy is advocated for the treatment of BSP-G and in selected cases of BSP-M. However, only partial resolution of clinical signs should be expected for BSP-M. No surgical treatment exists for BSP-Q calves, although spontaneous improvement is possible.

IMAGING DIAGNOSIS - MAGNETIC RESONANCE IMAGING OF INTRACRANIAL INFLAMMATORY FIBROSARCOMA IN A MIXED BREED DOG.

An 8-year-old mixed-breed dog presented with progressive behavioral changes and altered mentation. Magnetic resonance imaging (MRI) of the brain revealed an olfactory and frontal lobe extra-axial mass. The mass exhibited the following MRI signal intensity characteristics: T2W mixed, T1W iso- to hypointense, FLAIR hyperintense, and strong contrast enhancement. The mass was removed with cavitronic ultrasonic surgical aspirator (CUSA) assisted neurosurgery. Based on histopathological appearance and immunohistochemistry, the diagnosis of inflammatory fibrosarcoma was made. To our knowledge, this is the first report describing MRI characteristics of intracranial inflammatory fibrosarcoma in the veterinary literature.

Comparison of palmar digital neurectomy by the guillotine technique and palmar digital neurotomy associated with end-to-side neurorrhaphy in mares / Comparação entre neurectomia por técnica de guilhotina e neurotomia associada à neurorrafia em alça de balde em nervo digital palmar de éguas

Five mares were submitted to palmar digital neurectomy by the guillotine technique and palmar digital neurotomy followed by end-to-side neurorrhaphy (right and left thoracic limbs, respectively). Mares were checked for local pain sensation using hoof tester and submitted to lameness workup at 15-day intervals. No evidence of painful neuroma formation was detected. Palmar digital nerve (PDN) stump segments were collected within 60 days of surgery. Mean left and right limb PDN stump thickness corresponded to 5.96 mm and 7.16 mm, respectively. Schwann cells prevailed over connective healing tissue in all PDN stumps studied. Well-formed nerve-like structures with better organized nervous tissue and predominance of parallel nerve fiber orientation were documented in left limb PDN stumps. End-to-side neurorrhaphy tended to promote tissue organization, potentially reducing the chances of neuroma formation...

O nervo digital palmar (NDP) lateral do membro torácico direito (MTD) de cinco equinos fêmeas foi submetido à neurectomia pela técnica da guilhotina, e o do membro torácico esquerdo (MTE) à neurotomia e neurorrafia término-lateral. Os animais foram avaliados a cada 15 dias quanto ao teste de sensibilidade cutânea com pressão local com pinça de casco e de claudicação, não sendo notados sinais clínicos de neuroma doloroso. Aos 60 dias pós-cirurgia coletou-se segmentos dos cotos proximais dos NDPs. Os dos MTDs apresentavam em média, a espessura de 7,16 mm e aos dos MTEs de 5,96 mm. Nos cotos proximais dos nervos dos membros direito e esquerdo notou-se predominância de células de Schwann à grande quantidade de tecido conjuntivo cicatricial. Os do MTEs apresentavam estruturas de nervo típico, bem constituídas, com maior organização do tecido nervoso e predomínio de fibras nervosas orientadas paralelamente. A neurorrafia termino-lateral apresentou tendência a ocasionar maior organização entre as estruturas analisadas, o que lhe conferiu menor potencial em desenvolver neuromas dolorosos...

Minimally-invasive Technique for Injection into Rat Optic Nerve.

The rat optic nerve is a useful model for stem cell regeneration research. Direct injection into the rat optic nerve allows delivery into the central nervous system in a minimally-invasive surgery without bone removal. This technique describes an approach to visualization and direct injection of the optic nerve following minor fascial dissection from the orbital ridge, using a conjunctival traction suture to gently pull the eye down and out. Representative examples of an injected optic nerve show successful injection of dyed beads.