A novel extraoral ultrasound-guided approach for mandibular nerve block in Rahmani sheep.

BACKGROUND: Regional anesthesia is the favored choice in ruminant animals compared to general anesthesia, primarily due to its high safety margin and reduced demand for cost-intensive equipment in addition to its field applicability. Ultrasound-guided nerve block has gained significant attention in the field of veterinary medicine. This study utilized twenty-seven sheep of the native Rahmani breed to both demonstrate and evaluate the effectiveness of the ultrasound guided inferior alveolar nerve block technique. METHODS: The research comprised three phases: Phase 1 involved an anatomical examination of mandibles and sheep heads to locate the mandibular foramen and delineate the mandibular nerve course. Phase 2 included ultrasound-guided injection of methylene blue dye at specific sites along the mandibular nerve in cadaveric sheep heads. In Phase 3, clinical implementation of ultrasound-guided inferior alveolar nerve blocks was conducted in 27 live sheep, assessing efficacy, onset, and duration. RESULTS: Vertical extraoral ultrasound-guided nerve block was achieved successfully in 25 sheep (98%). A preliminary cadaveric study showed good distribution of the injectate at the mandibular nerve site. The mean onset time was 138 ± 18 s, and the mean duration time was 54 ± 4.1 min. Prominent analgesia of the ipsilateral mandible, medial surface of the cheek, and lateral border of the tongue was observed. CONCLUSIONS: Ultrasound-guided mandibular nerve block holds promise as a technique for providing effective and safe anesthesia in sheep undergoing mandibular procedures.

Comparison of a blind and an ultrasound-guided technique for Retrobulbar anesthesia in dogs undergoing unilateral subconjunctival enucleation.

OBJECTIVE: This study compared the quality of retrobulbar anesthesia using a blind inferior-temporal palpebral approach (ITP) with an ultrasound-guided supratemporal (ST) technique in dogs undergoing unilateral enucleation. ANIMAL STUDIED: Twenty-one client-owned dogs were undergoing enucleation. PROCEDURES: Dogs were randomly assigned to receive ITP (n = 10) or ST (n = 11) with 0.5% ropivacaine at 0.1 mL/cm of neurocranial length. The anesthetist was blinded to the technique. Intraoperative data included cardiopulmonary variables, inhalant anesthetics requirement, and requirement for rescue analgesia (intravenous fentanyl 2.5 mcg/kg). Postoperative data included pain scores, sedation scores, and need for intravenous hydromorphone (0.05 mg/kg). Treatments were compared using Wilcoxon's rank sum test or Fisher's exact test as appropriate. Comparison of variables over time were tested using a mixed effect linear model on rank. Significance was set at p = 0.05. RESULTS: Intraoperative cardiopulmonary variables and inhalant requirements were not different between groups. Dogs receiving ITP required median (interquartile range, IQR) 1.25 (0, 2.5) mcg/kg intraoperative fentanyl while those receiving ST required none (p < 0.01). Intraoperative fentanyl was required in 5/10 and 0/11 of dogs in the ITP and ST groups, respectively (p = 0.01). Postoperative analgesia requirements were not significantly different between groups; 2/10 and 1/10 dogs in the ITP and ST groups, respectively. Sedation score negatively affected pain score (p < 0.01). CONCLUSIONS: The ultrasound-guided ST technique was more effective at decreasing intraoperative opioid requirements than the blind ITP approach in dogs undergoing unilateral enucleation.

Image analysis comparison of nerve staining with food dye, methylene blue or tissue marker.

OBJECTIVE: Novel locoregional techniques use dye studies to confirm successful nerve targeting. The goal was to objectively quantify and compare nerve staining characteristics of dye mixtures commonly reported in the literature using image analysis software. STUDY DESIGN: Prospective, randomized cadaveric study. METHODS: Thirty-six brachial plexus nerves from unpreserved pig cadavers were randomized into three groups of 12: FD (1:10 mixture of blue food dye and bupivacaine 0.5%), MB (methylene blue 1%) and TM (0.1:10 mixture of blue tissue marker and lidocaine 2%). Nerves were immersed in dye for 1, 15, 30 or 60 minutes (n = 3 each). Images of nerves before immersion (baseline) and at each time point with epineurium intact (superficial staining) and after longitudinal bisection (deep staining) were processed using image analysis software. Color saturation values were divided into quartiles (dark, medium-dark, medium-light or light). Percentage of stained nerve area in each quartile was calculated and compared using two-way anova. RESULTS: Superficially, at minute 1, dark saturation covered 40% of nerve area in FD versus 19% in MB (p = 0.04) and 0% in TM (p < 0.0001). In bisected nerves, dark and medium-dark saturations occurred only in FD; medium-light saturation comprised anywhere from 4% to 22.5% over time in FD versus <1% at any time in MB (p = 1.000; p = 0.343; p = 0.383; p = 0.262). Deep staining was not found in TM at any point. CONCLUSION AND CLINICAL RELEVANCE: Food dye rapidly stains superficial and deep nerve layers. Based on these characteristics, investigators can choose the appropriate dye for their study.

Ultrasound-guided caudal quadratus lumborum block combined with the greater ischiatic notch plane block as motor-protective analgesia for the pelvic limb in dogs.

OBJECTIVE: To develop an ultrasound-guided caudal quadratus lumborum block (C-QLB) technique in canine cadavers and to compare sensory and motor blockade resulting from the combination of ultrasound-guided greater ischiatic notch (GIN) plane and C-QLB approaches (GIN-CQLB group) versus a lumbosacral plexus (LSP group) approach [combination of lateral pre-iliac (LPI) and parasacral (PS) techniques] in dogs. STUDY DESIGN: Descriptive anatomical study and prospective randomized, blinded, experimental crossover trial. ANIMALS: A total of six canine cadavers and six adult Beagle dogs. METHODS: Phase I: following ultrasound-guided C-QLB injections of 0.3 mL kg-1 of dye, using the interfascial plane located lateral to the quadratus lumborum muscle at the level of the sixth lumbar vertebra (L6) as injection point, the spread of injectate and nerve staining was evaluated using gross anatomical dissection. PHASE II: sensory and motor blockade achieved with the GIN-CQLB or LSP blocks in Beagle dogs were evaluated and compared. The assigned technique was performed with 2% lidocaine: 0.2 mL kg-1 for the GIN and PS approaches and 0.3 mL kg-1 for the C-QLB and LPI approaches. RESULTS: Dissection revealed distribution of dye around the lumbar hypaxial musculature, extending into the paravertebral spaces, with staining of 3 (2-4) [median (interquartile range)] spinal nerves, spanning L3 to L6. The median motor blockade in the GIN-CQLB and LSP groups was 7 (7-8) versus 16 (10-16) (p = 0.026), whereas the median sensory blockade was 5 (4-5) versus 3 (3-3) (p = 0.025), respectively. CONCLUSION AND CLINICAL SIGNIFICANCE: The GIN-CQLB approach desensitized the thigh dermatomes effectively. Compared with the LSP approaches, GIN-CQLB exhibits a motor-protective effect by preserving tonic muscle function.

Investigation of a maxillary nerve block technique in guinea pigs (Cavia porcellus): A cadaveric study comparing two injectate volumes.

OBJECTIVE: To investigate and describe an extraoral approach to perform a maxillary nerve block in guinea pigs. STUDY DESIGN: Prospective, randomized, blinded, descriptive, cadaveric study. ANIMALS: A total of 14 adult guinea pig cadavers. METHODS: Two cadavers were used for anatomic dissection and determination of maxillary nerve block approach. A maxillary nerve block via infraorbital approach was then performed in 12 cadavers. A low volume (0.1 mL) or high volume (0.2 mL) of diluted methylene blue injectate was randomly assigned to the right or left side, with the other volume used for the contralateral side. The maxillary nerve was dissected after each injection by an investigator blinded to injectate volume. The region of dye distribution was identified, and the degree of staining assigned an accuracy score (0-2). Nerve coverage was considered adequate if ≥6 mm of circumferential staining was present. RESULTS: Accuracy evaluation indicated successful dye deposition in 10/12 [2 (0-2), median (range)] injections in the low volume group and 8/12 [2 (1-2)] injections in the high volume group. The majority (79.2%) of injections resulted in adequate nerve staining. There were no statistically significant differences between injectate volumes for accuracy (p = 0.64) or adequacy (p > 0.99) of staining. CONCLUSIONS: The infraorbital approach is a simple and practical method for maxillary nerve blockade in guinea pigs. An injectate volume of 0.1 mL results in adequate maxillary nerve coverage; however, additional studies are needed to assess the efficacy in clinical use.

Ultrasound-guided retromammillary injections in dogs: a feasibility, descriptive and anatomical study.

OBJECTIVE: To evaluate the feasibility of an ultrasound-guided technique targeting the medial branches of the dorsal ramus of the spinal nerves (DRSN) by injecting a dye solution at the caudal aspect of the base of lumbar mammillary processes [i.e. the retromammillary (RM) space]. STUDY DESIGN: Feasibility, descriptive, anatomical study. ANIMALS: Eleven canine cadavers. METHODS: Using anatomical dissections, the relationship between the mammillary processes and the branches of the DRSN of the thoracolumbar and lumbar spine was studied in two cadavers. Subsequently, ultrasound-guided RM injections were administered in nine cadavers, randomly assigned to low volume (LV; 0.01 mL kg-1) of a dye solution at multiple points from L3 to L6 on one side, and high volume (HV; 0.4 mL kg-1) at a single L4 point on the contralateral side. Gross anatomical dissections were immediately performed after the injections. The RM injections were feasible if ultrasonographic landmarks were identifiable in at least 80% of cases, and 80% of LV injections showed medial branch staining. A one-sample binomial test was used for testing feasibility. RESULTS: The medial branches emerged shortly after the DRSN exited the intervertebral foramen and traveled towards the caudal aspect of the base of the mammillary process, which served as the target injection point. With LV, 36 out of 36 (100%) injected medial branches were stained, meeting the criteria of feasibility (p < 0.001). The median (range) number of stained medial branches per cadaver were 4 (4-4) and 2 (1-3), with LV and HV, respectively. Although no lateral branches were stained with LV, 1 (0-2) was stained with HV. Neither ventral branch staining nor epidural spread was noted in any cadaver. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided RM injections are feasible and allow for selective staining of the medial branch of the DRSN in canine cadavers at the lumbar spine.

Ultrasound-guided and 'blind' sciatic nerve injection techniques: Comparison in rat cadavers.

OBJECTIVE: To compare the success rate and extent of sciatic nerve staining with a bupivacaine-dye solution using two injection techniques: 'blind' or ultrasound-guided approach. STUDY DESIGN: Prospective, experimental, randomized, cadaveric study. ANIMALS: Adult female Wistar rat cadavers [n = 24, mass 352 g (323-374)]. METHODS: Each sciatic nerve was randomly allocated to one of two groups: 'blind' (group B) or ultrasound-guided approach (group US) to injection. Following injection of bupivacaine-dye solution (0.1 mL), gross anatomical dissection was performed to visualize nerve staining, categorizing it as either positive or negative. The length of nerve staining was then measured and visual inspection conducted to identify potential nerve damage. Fisher's exact test was used to compare positive or negative nerve staining, and the Wilcoxon signed rank test used to compare the length of nerve staining between groups. RESULTS: In group B, the bupivacaine-dye solution stained 16/24 sciatic nerves (67% success). In group US, staining was successfully observed in all 24 nerves (100% success, p < 0.004). The length of nerve staining [median (interquartile range)] was 2 (2-3) mm in group B and 5 (4-6) mm in group US (p < 0.001). One sciatic nerve in group B had injectate distributed over 16 mm, suggestive of an intraneural injection. No signs of laceration or nerve damage were visible under 6× magnification in either group. CONCLUSIONS AND CLINICAL RELEVANCE: The ultrasound-guided approach for sciatic nerve injection demonstrated a higher success rate with superior injectate distribution when compared with the 'blind' approach. Ultrasound guidance is recommended over a 'blind' approach for sciatic nerve block in rats when possible.

Ultrasound-guided sciatic nerve block in Wistar rat cadavers: Relevant anatomy and injection distribution.

OBJECTIVE: To investigate the feasibility of an ultrasound-guided sciatic nerve block by describing the sonoanatomy and comparing the distribution of two volumes of bupivacaine dye solution for nerve staining. STUDY DESIGN: Randomized, experimental, assessor-blinded cadaveric study. ANIMALS: A total of 40 adult female Wistar rat cadavers. METHODS: After studying the sonoanatomy of the sciatic nerve and adjacent structures using a high-resolution linear transducer (19-5 MHz), rat cadavers were randomly divided into two groups that were administered either 0.1 mL (group 0.1) or 0.2 mL (group 0.2) of bupivacaine dye solution per nerve, delivered via an in-plane technique. The extent of nerve staining was subsequently evaluated following dissection. Statistical analysis consisted of assessing data distribution using the Shapiro-Wilk test, followed by paired t-tests for continuous data, Mann-Whitney U test and McNemar's test for categorical data. Statistical significance was defined as p < 0.05. RESULTS: The sciatic nerve was identified bilaterally as a double ellipsoid-shaped image, surrounded by a hyperechoic fascia separating the biceps femoris from the adductor muscle. The hypoechoic structure formed by the bupivacaine dye solution around the nerve was effectively visualized using ultrasound imaging. Sciatic nerve staining was successfully achieved in all pelvic limbs, with dye spread of 4.82 ± 1.55 mm and 5.47 ± 2.18 mm in groups 0.1 and 0.2, respectively (p = 0.128). CONCLUSIONS AND CLINICAL RELEVANCE: This study achieved a detailed understanding of the sonoanatomy of the sciatic nerve and its adjacent structures, highlighting the feasibility of the ultrasound-guided technique for injection in Wistar rats. Furthermore, the results show a comparable distribution of dye solution in both groups. Use of the ultrasound-guided sciatic nerve block technique in rats not only exhibits substantial potential for regional anesthesia but also opens avenues for translational studies.

Ultrasound-guided trigeminal nerve approach at the level of the pterygopalatine fossa in cat cadavers.

OBJECTIVE: To describe an ultrasound-guided suprazygomatic approach to the trigeminal nerve block in cat cadavers. STUDY DESIGN: Prospective descriptive study. ANIMALS: Ten feline cadaver heads. METHODS: A 25:75 methylene blue-iopamidol mixture (0.1 mL cm-1 cranium length) was injected into 10 cadaver heads using an ultrasound-guided suprazygomatic approach. A computed tomography (CT) scan was performed to identify contrast presence at the orbital fissure, foramen rotundum and ovale, followed by anatomical dissection to identify staining of the pterygopalatine fossa (PPF), extraconal retrobulbar area, mandibular and maxillary nerves. Descriptive statistics were used to summarize results. RESULTS: A total of 20 injections were performed. Of these, 1/20 misinjection occurred and excluded from further reporting. The volume of injectate was 0.9 (0.9-1.1) mL [median (range)]. Staining of the PPF, extraconal space, maxillary and mandibular nerves over more than 6 mm was achieved in 19/19 (100%), 18/19 (95%), 17/19 (89%) and 19/19 (100%) of injections, respectively. CT showed presence of contrast within 5 mm of the orbital fissure, foramen rotundum and ovale in 18/19 (95%), 19/19 (100%) and 19/19 (100%) of the injections, respectively. No intracranial migration was observed. CONCLUSIONS AND CLINICAL RELEVANCE: This cadaver study illustrates that the suprazygomatic ultrasound-guided trigeminal nerve injection technique can successfully stain the PPF, retrobulbar cone extraconally, mandibular and maxillary nerves. Consequently, this technique has the potential to be used in vivo in cats to desensitize areas innervated by the trigeminal nerve.

Ultrasound-guided ventral approach to the brachial plexus block in barred owls (Strix varia): a cadaveric study.

OBJECTIVE: To develop an ultrasound (US)-guided ventral approach to the brachial plexus (BP) and evaluate nerve anatomy and staining in barred owl cadavers. STUDY DESIGN: Prospective, cadaveric study. ANIMALS: Eleven adult male and female barred owl cadavers with a body mass of 0.43-0.98 kg. METHODS: Eleven frozen cadavers were thawed for 48 hours, weighed and assigned a body condition score. Ten cadavers were placed in dorsal recumbency with wings abducted. US-guided visualization of the BP was achieved by placing a 13-6 MHz linear probe over the ventral aspect of the scapulohumeral joint, parallel to the sternum. A 22 gauge, 50 mm insulated needle was advanced in-plane in a caudal-to-cranial direction. In each owl, injection targeting one BP was performed with 0.4 mL kg-1 of a 1:1 0.5% ropivacaine and 1% methylene blue solution. Dissection was performed 15 minutes postinjection. Nerve staining was deemed successful if ≥ 1 cm of circumferential staining was achieved. The eleventh owl cadaver was injected with a 1:1 solution of 1% methylene blue and 74% ioversol contrast into both wings, and computed tomography (CT) was performed just before and 15 minutes after injection. RESULTS: The BP was clearly identified ultrasonographically in cadavers weighing > 0.5 kg. An injectate volume of 0.4 mL kg-1 provided complete staining of the BP branches in all cadavers. CT scan revealed no contrast within the coelomic cavity. CONCLUSIONS AND CLINICAL RELEVANCE: The US-guided BP injection using a ventral approach was easily performed in barred owl cadavers weighing > 0.5 kg. The injection of 0.4 mL kg-1 of a ropivacaine-dye solution resulted in complete staining of the BP branches in all wings, suggesting that this technique could provide analgesia for structures distal to the scapulohumeral joint. Clinical studies are necessary to confirm the safety and efficacy of this technique in barred owls and other bird species.

Ultrasound-guided sciatic nerve block injections in barred owl (Strix varia) cadavers.

OBJECTIVE: To describe an ultrasound-guided approach to the sciatic nerve and the distribution of nerve staining using two injectate volumes of dye in barred owls. STUDY DESIGN: Descriptive, randomized, assessor-blinded, cadaveric study. ANIMALS: Twelve barred owl cadavers. METHODS: The sciatic nerve was visualized with a 13-6 MHz linear ultrasound probe placed on the medial aspect of the proximal femur in barred owl cadavers. A needle was inserted at the proximal caudal thigh, and cranially advanced in-plane until the tip was immediately adjacent and ventral to the sciatic nerve. Eleven owls were injected bilaterally with a 1:1 solution of 1% methylene blue and 0.5% ropivacaine, with high-volume (HV; 0.4 mL kg-1) and low-volume (LV; 0.2 mL kg-1) treatments. Nerve staining ≥ 1 cm circumferentially was determined by dissection 15 minutes post-injection. The coelom was then opened to inspect for aberrant dye spread. In one barred owl cadaver, a 1:1 solution of 1% methylene blue and 74% ioversol contrast was injected, and computed tomography was performed immediately before and 15 minutes after injection for evaluation of injectate spread. RESULTS: The HV treatment (0.4 mL kg-1) resulted in successful nerve staining in 100% of injections, whereas the LV treatment (0.2 mL kg-1) resulted in successful nerve staining in 91% of injections. There was no leakage of injectate into undesired locations (e.g. coelomic cavity) in any cadaver. CONCLUSIONS AND CLINICAL RELEVANCE: In barred owls, the sciatic nerve can be visualized with ultrasound and injecting a ropivacaine/dye solution under ultrasound guidance successfully stained the sciatic nerve in the majority of cases. This technique holds potential for providing analgesia distal to the stifle joint; however, further investigations are necessary to evaluate its practical application in a clinical setting.

Evaluation of preoperative rectus sheath block with bupivacaine for analgesia in cats undergoing ovariohysterectomy: a cadaveric and randomized clinical study.

OBJECTIVE: Phase 1: to determine the feasibility of desensitizing ventral branches of spinal nerves within the rectus sheath using an ultrasound-guided rectus sheath block (USRSB). Phase 2: to determine the effect of preoperative USRSB on intraoperative responses to surgical stimulation and postoperative pain. STUDY DESIGN: Cadaveric study and prospective, randomized, blinded, parallel-arm clinical trial. ANIMALS: A group of five cat cadavers and 37 shelter-owned cats undergoing ovariohysterectomy. METHODS: Phase 1: anatomical dissection was performed on one uninjected cadaver. Abdominal walls were dissected in four cadavers (eight hemiabdomens) following bilateral USRSB using 1:1 new methylene blue and 0.5% bupivacaine (0.8 mL kg-1 total). Phase 2: preoperative bilateral USRSB was performed with 0.8 mL kg-1 of 0.25% bupivacaine (RSB) or equivalent volume of 0.9% saline (CONTROL). Intraoperative systolic arterial blood pressure (SAP), heart rate (HR), respiratory rate (fR) and vaporizer setting (vap%) were recorded before skin incision, during celiotomy and abdominal wall closure. In recovery, cats were administered robenacoxib (2 mg kg-1; CONTROL) or 0.9% saline (0.1 mL kg-1; RSB) subcutaneously. Postoperative pain was evaluated for 6 hours using the Glasgow Composite Measure Pain Scale. RESULTS: Phase 1: spinal nerves T9-L3 were identified within the rectus sheath, and stained in 0%, 40%, 63%, 75%, 100%, 88%, 50% and 13% of hemiabdomens, respectively. Phase 2: 37 cats were included (RSB, n = 17; CONTROL, n = 20). Intraoperatively, SAP, HR and fR were not significantly different between groups. Vap% was significantly lower in RSB during celiotomy (p = 0.036) and closure (p = 0.044). Postoperatively, RSB cats were 5.3 times (95% CI 1.8-8.3) more likely to require rescue analgesia than CONTROL cats. CONCLUSIONS AND CLINICAL RELEVANCE: During surgery, USRSB with bupivacaine offered minor benefits and provided markedly less postoperative analgesia than robenacoxib, indicating that relying on USRSB provides insufficient postoperative analgesia for ovariohysterectomy in cats.

A comparison of the motor effects and analgesic efficacy following lumbar plexus block combined with sciatic nerve block or epidural in dogs undergoing tibial plateau leveling osteotomy.

OBJECTIVE: To compare motor effects and analgesic efficacy following an ultrasound-guided lateral approach to lumbar plexus blockade at L7 and sciatic nerve blockade (LPSNB) against epidural injection in dogs undergoing tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Prospective, randomized, blinded clinical trial. ANIMALS: A total of 27 healthy adult dogs undergoing unilateral TPLO surgery. METHODS: Dogs were allocated to either LPSNB (bupivacaine 2 mg kg-1, 0.75%) or epidural (morphine PF 0.1 mg kg-1 and bupivacaine 0.5 mg kg-1, 0.75%). Other aspects of clinical management were identical, including anesthetic drug protocol, area of presurgical clipping and bladder care. Time to perform the block, response to surgical stimuli, pain scores, rescue analgesia, time to stand and walk, motor score and time to first urination were recorded. One evaluator, unaware of treatment status, performed all evaluations. Student's t-test or Mann-Whitney U test was used to compare continuous variables between groups, and Fisher's exact test for categorical variables. RESULTS: Median (range) times to stand and walk were shorter for LPSNB [60 (40-120) minutes and 90 (60-150) minutes, respectively, p = 0.003] than for epidural [150 (120-240) minutes and 180 (120-360) minutes, respectively, p = 0.006]. Four dogs required rescue intraoperatively (three in epidural group, one in LPSNB group, p = 0.438). Pain scores over the 24 hour evaluation period were similar, and not significantly different, for each group. Time to spontaneous urination [LPSNB, 330 (240-360) minutes; epidural, 300 (120-1440) minutes, p = 1.0] did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE: An ultrasound-guided lateral paravertebral approach to the lumbar plexus within the psoas compartment at L7, combined with sciatic nerve blockade, allows faster return to normal motor function, with similar pain control and impact on urination when compared with epidural in dogs after TPLO surgery.

Unexpected diagnosis of canine lymphoma when performing an ultrasound-guided cystocentesis on a 3-year-old Rottweiler dog.

A 3-year-old spayed female Rottweiler dog was brought to a veterinary clinic because of weakness, lethargy, and hair coat changes. Hematology and clinical chemistry assessments revealed anemia, hypoalbuminemia, hyperglobulinemia, and hypothyroid. After persistent pyuria, an ultrasound-guided cystocentesis was completed, which revealed a large abdominal mass. A presumptive diagnosis of canine lymphoma with renal spread was made. Due to a poor prognosis, the dog was euthanized.

Diagnostic inattendu de lymphome canin lors de la réalisation d'une cystocentèse échoguidée sur un chien Rottweiler de 3 ans. Une chienne Rottweiler stérilisée de 3 ans a été amenée dans une clinique vétérinaire en raison de faiblesse, de léthargie et de changements de pelage. Les évaluations hématologiques et chimiques cliniques ont révélé une anémie, une hypoalbuminémie, une hyperglobulinémie et une hypothyroïdie. Après une pyurie persistante, une cystocentèse échoguidée a été réalisée, révélant une masse abdominale volumineuse. Un diagnostic présomptif de lymphome canin à propagation rénale a été posé. En raison d'un mauvais pronostic, le chien a été euthanasié.(Traduit par Dr Serge Messier).

Cardiovascular changes, laboratory findings and pain scores in calves undergoing ultrasonography-guided bilateral rectus sheath block before herniorrhaphy: a prospective randomized clinical trial.

BACKGROUND: The study aimed to assess the clinical utility of a multiparametric approach to measure the impact of bilateral ultrasound-guided rectus sheath blocks (RSB) on heart rate, serum cortisol concentrations, and pain in calves undergoing herniorraphy. Fourteen calves were randomly assigned to receive either the RSB (RSB group, n = 7, injected with 0.3 mL/kg of bupivacaine 0.25% and 0.15 µg/kg of dexmedetomidine per side) or a sham injection (CG group, n = 7, injected with an equivalent volume of sterile saline solution). Monitoring included (i) continuous Holter recording from 120 min pre-surgery to 120 min post-surgery; (ii) serum cortisol concentration (SC) at -150 min pre-surgery (baseline), induction time, skin incision, end of surgical procedure (EP-t), and then 30 min, 45 min, 60 min, 120 min, 360 min after recovery; (iii) UNESP-Botucatu pain evaluation at -150 min pre-surgery and 30 min, 45 min, 60 min, 120 min, 240 min, 360 min after recovery. RESULTS: A significant difference in the heart rate was observed within the RSB group, in the time frame between 120 min to induction compared to the time frame between induction to EP-t period. The SC concentration was significantly higher in the CG at the skin incision. Calves in the RSB group recorded significantly lower pain scores at 45 min, 60 min, 120 and 240 min after recovery. CONCLUSIONS: The study demonstrated that monitoring heart rate and serum cortisol concentrations effectively quantified the effects of RSB during surgery. At the same time, the UNESP-Botucatu pain scale identified effects post-surgery when the calves regained consciousness. Overall, ultrasound-guided RSB appeared to enhance the well-being of calves undergoing herniorrhaphy.

Transvaginal ultrasound-guided oocyte retrieval in cattle: State-of-the-art and its impact on the in vitro fertilization embryo production outcome.

Transvaginal ultrasound-guided oocyte retrieval (commonly called OPU) and in vitro embryo production (IVP) in cattle has shown significant progress in recent years, in part, as a result of a better understanding of the full potential of these tools by end users. The combination of OPU and IVP (OPU-IVP) has been successfully and widely commercially used worldwide. The main advantages are a greater number of embryos and pregnancies per unit of time, faster genetic progress due to donor quick turn around and more elite sires mating combinations, larger spectrum of female age (calves, prepuberal, heifer, cow) and condition (open, pregnant) from which to retrieve oocytes, a reduced number of sperm (even sexed) required to fertilize the oocytes, among other benefits. OPU-IVP requires significant less donor preparation in comparison to conventional embryo transfer (<50% of usual FSH injections needed) to the extent of no stimulating hormones (FSH) are necessary. Donor synchronization, stimulation, OPU technique, oocyte competence, embryo performance, and its impact on cryopreservation and pregnancy are discussed.

Administration of carbetocin-a long-acting oxytocin analogue-before sperm collection by transrectal ultrasound-guided massage of the accessory sex glands in bucks (Capra hircus) and ibexes (Capra pyrenaica).

Transrectal ultrasonic-guided massage of the accessory sex glands (TUMASG) is a technique that allows collecting semen requiring few electrical stimuli or even no pulse. A long-acting analogue of oxytocin (carbetocin, 0.1 mg) was i.v. administered before TUMASG in 10 conscious bucks (Experiment 1) and 10 anaesthetized Iberian ibexes (Experiment 2) to shorten the time of semen collection, decrease the number of electrical stimuli and/or improve the semen quality. The ejaculated volume, concentration, quality parameters and kinetics variables of the sperm were determined in fresh semen. The time length of the procedures and the number of electric pulses applied were recorded. Furthermore, stress response indicators (number of vocalizations in Experiment 1; heart and respiratory rates, rectal temperature, cortisol levels, totals proteins and neutrophil-to-lymphocyte ratio in Experiment 2) were documented. In bucks, the administration of carbetocin tended to shorten the time needed for semen collection but no-showed differences in the fresh seminal quality. In the Iberian ibexes, there were no significant differences between groups in the time length of procedures or in the number of animals that ejaculated. Carbetocin administration only reduced the respiratory rate, did it modify fresh semen characteristics in ibexes. In conclusion, the administration of carbetocin did not appear as a useful tool to improve welfare during semen collection with TUMASG or semen quality in conscious bucks and anaesthetized ibexes, having only slight advantages related to the procedure.

Safety and accuracy of blind vs. ultrasound-guided dorsal retrobulbar nerve blocks in horses-A cadaveric study.

OBJECTIVE: There is limited knowledge regarding the safety and accuracy of ultrasound-guided retrobulbar nerve blocks in horses. The aim of this study was to compare these parameters between blind and ultrasound-guided injection techniques for the dorsal retrobulbar nerve block in horses. METHODS: Equine cadaver heads were used to inject the retrobulbar space with contrast medium (CM). Injections were performed either blindly based on anatomic landmarks (blind group, n = 44) or under ultrasonographic guidance (US-group, n = 44), equally divided between an experienced and unexperienced operator. Needle position and distribution of CM were assessed with computed tomography imaging and evaluated by a board-certified veterinary diagnostic imager blinded to the technique. Safety and accuracy of both techniques were compared. RESULTS: Ocular penetration was observed in two cases (n = 2/44) in the blind group but not in the US group (n = 0/44). No intrathecal, intraneural, or intravascular injections were seen in either group. Safety was significantly improved in the US group (p = .026). There was no statistically significant difference between the groups regarding the accuracy of the injection. Excellent accuracy was achieved more often with the ultrasound-guided technique (n = 11/22) than with the blind technique (n = 7/22) when performed by the unexperienced operator, but this difference was not statistically significant. CONCLUSION: To prevent globe-threatening complications and improve the safety of the injection, we recommend using the ultrasound-guided injection technique for the dorsal retrobulbar nerve block.

Surgical description and outcome of ultrasound-guided minimally invasive parathyroidectomy in 50 dogs with primary hyperparathyroidism.

OBJECTIVE: To describe the surgical technique and clinical outcome of minimally invasive parathyroidectomy for primary hyperparathyroidism (PHPT) in the dog. ANIMALS: Fifty client-owned dogs with PHPT that underwent minimally invasive parathyroidectomy. STUDY DESIGN: Retrospective cohort study. METHODS: An ultrasound-guided mini lateral approach was made via a plane established between the sternocephalicus muscle and sternohyoideus muscles to expose the thyroid gland and enlarged parathyroid gland. Abnormal parathyroid glands were removed en bloc via partial thyroidectomy. The technique for bilateral disease was similar, the skin incision was made on midline and moved laterally to develop the above-mentioned plane of dissection. Age, sex, breed, bodyweight, ultrasound findings, histopathological diagnosis, surgical time, preoperative clinical signs, and clinical outcome were extracted from the records for descriptive statistics. RESULTS: A total of 62 glands were surgically removed, including 17 hyperplastic glands (17/62, 27.4%), 34 adenomas (34/62, 54.8%), and two carcinomas (2/62, 3.2%). Hypercalcemia resolved shortly after surgery in 44 dogs (44/45, 97.8%). One dog had recurrent hypercalcemia (1/45, 2.2%), one dog had persistent hypercalcemia (1/45, 2.2%), two dogs had permanent hypocalcemia requiring life-long calcitriol supplementation (2/45, 4.4%), and one dog died from clinical hypocalcemia (1/45, 2.2%). CONCLUSION: Minimally invasive parathyroidectomy was associated with a low morbidity and led to favorable outcomes in 44/45 dogs in this series. CLINICAL SIGNIFICANCE: The results of this study supports the use of minimally invasive parathyroidectomy to treat PHPT in dogs.

Ultrasound-guided lateral pericapsular hip desensitization of the articular branches of the cranial gluteal nerve: A canine cadaveric study and feasibility study in dogs.

OBJECTIVE: To develop and assess the feasibility, as a diagnostic block, of an ultrasound-guided lateral pericapsular hip desensitization (L-PHD) technique in dogs. STUDY DESIGN: Prospective, randomized, anatomical and feasibility study. ANIMALS: A total of 11 canine cadavers and eight adult dogs scheduled for acetabular surgical denervation. METHODS: After studying the ultrasound anatomy of the lateral aspect of the gluteal region and determining an acoustic window to perform an ultrasound-guided L-PHD in three canine cadavers, the right and left hemipelves of eight canine cadavers were injected in the interfascial plane located lateral (LL-PHD group) or medial (LM-PHD group) to the deep gluteal muscle, with 0.05 mL kg-1 of dye per hip on each cadaver. The staining of the pericapsular nerves was assessed by anatomical dissection. Then, the LM-PHD was performed using 2% lidocaine as a diagnostic block in dogs scheduled for acetabular surgical denervation. Positive predictive value (PPV) was calculated for those animals who had favorable outcomes after acetabular surgical denervation. RESULTS: The ultrasound-guided LL-PHD and LM-PHD could be performed by inserting the needle lateral and medial to the deep gluteal muscle. Ultrasound-guided LL-PHD stained the cranial gluteal nerve and its muscular branches in all injections and partially stained the lumbosacral trunk in two out of eight cadavers. The LM-PHD selectively stained the articular branches of the cranial gluteal nerve in all but one cadaver. The PPV for LM-PHD successful test prediction was 85.7% (95% confidence interval: 48.6% to 98.6%). CONCLUSIONS: and clinical significance Ultrasound-guided LM-PHD using 0.05 mL kg-1 of dye selectively stained the articular branches of the cranial gluteal nerve in canine cadavers. The LM-PHD technique is feasible and could be used as a diagnostic block before acetabular surgical denervation in dogs.