Development and evaluation of an anatomically designed and 3D printed device to enhance orotracheal intubation success in rabbits by inexperienced veterinarians.

OBJECTIVE: To assess whether the use of a three-dimensional (3D) printed device enhances the success rate of orotracheal intubation in rabbits. STUDY DESIGN: Prospective, crossover randomized controlled trial. ANIMALS: A total of six mixed-breed rabbits. METHODS: A device to guide the endotracheal tube was designed based on computed tomography images and then manufactured using 3D printing. Rabbits were randomly assigned for intubation by two inexperienced veterinarians using the blind (BLI), borescope- (BOR) or device- (DEV) guided techniques. Success rate, number of attempts, time to success, injury scores and propofol dose were recorded and compared. Significance was considered when p < 0.05. RESULTS: Success rate was higher in DEV (58.3%) than in BLI (8.3%) (p < 0.023), but not different from that in BOR (41.6%). Total time until successful intubation was lower in DEV (45 ± 23 seconds) and BOR (85 ± 62 seconds) than in BLI (290 seconds; p < 0.006). Time for the successful attempt was lower for DEV (35 ± 10 seconds) and BOR (74 ± 43 seconds) than in BLI (290 seconds; p < 0.0001). The propofol dose required was lower for DEV (2.3 ± 1.2 mg kg-1) than for BLI (3.4 ± 1.6 mg kg-1) (p < 0.031), but not different from BOR (2.4 ± 0.9 mg kg-1). Number of attempts and oxygen desaturation events were not different among techniques (p < 0.051 and p < 0.326, respectively). Injury scores [median (range)] before and after attempts were different in BLI [0 versus 1 (0-3), p < 0.005] and BOR [0 (0-1) versus 1 (0-3), p < 0.002] but not in DEV [0 (0-2) versus 0 (0-3), p < 0.109]. CONCLUSIONS AND CLINICAL RELEVANCE: The device facilitated orotracheal intubation with a time similar to the borescope-guided technique but faster than the traditional blind technique.

Past, Present, and Future Trends of Nickel Titanium Rotary Instrumentation.

This article reviews the historical development, properties, and trends of nickel titanium rotary instrumentation use for the veterinary endodontist.

Evaluation of a Fixed-Angle Wedge Osteotomy Guide.

OBJECTIVE: The aim of this study was to evaluate a fixed-angle cutting guide designed to aid in the performance of coplanar wedge osteotomies using a proximal tibial cranial closing wedge ostectomy model. STUDY DESIGN: A 30-degree cranial closing wedge ostectomy was created using canine tibia models with either a standard template (method T) or a wedge osteotomy guide (method G) by two surgeons. One surgeon was experienced with both procedures, and one surgeon had no previous experience with the wedge guide. The ostectomy wedges were evaluated for wedge angle, using a digital protractor, and coplanarity by using digital photographs and screen-measuring software. RESULTS: The mean (standard deviation) wedge angles of the T and G groups were 28.16 (1.33) and 28.4 degrees (1.46) respectively. The mean (standard deviation) divergence angles of the T and G groups were 3.21 (1.86) and 2.22 degrees (1.69) respectively. The measured reference angles of the template and cut guides were 31.27 and 29.60 degrees respectively. Individual and cross-surgeon analysis of outcomes found no significant differences when comparing wedge angle or coplanarity with either method regardless of surgeon experience. However, mean wedge angle of group G was significantly closer to the measured reference angles than group T (p < 0.01). CONCLUSION: Use of a fixed-angle surgical wedge guide was successful in consistently producing accurate closing wedge ostectomies regardless of surgeon experience. These results show that use of the guide is a valid method for performing wedge ostectomies.

Feasibility of a disposable canister-free negative-pressure wound therapy (NPWT) device for treating open wounds in horses.

BACKGROUND: Wounds are among the most common medical conditions affecting horses and have a major economic impact on the horse industry. Wound healing in horses is distinct to that documented in other species, and often results in delayed healing and extensive scarring, with compromised functional and aesthetic outcomes. To date, there is no conventional method objectively proven to accelerate healing or to successfully prevent complications associated with second intention healing. Several effects of Negative Pressure Wound Therapy (NPWT) may be particularly useful to the management of wounds in horses. However, cumbersome designs of classic NPWT devices render them unsuitable for equine practice. A new lightweight, portable and disposable unit of NPWT (PICO®), should facilitate the use of this modality by equine practitioners. The aim of this study was to evaluate the feasibility of using this canister-free system to treat experimental open wounds in horses. RESULTS: No difficulties were encountered with the application or maintenance of the PICO® system during the ex vivo experiment or during the preliminary in vivo experiment conducted on intact skin. All horses readily tolerated the PICO® but difficulties with adhesion and seal prevented the completion of the experimental wound study despite the use of many adjunctive adhesives. CONCLUSION: The current PICO® dressing design is not suitable to be used as a dressing for open wounds in horses though the device is well tolerated by equine patients. A dressing with a wider adhesive edge, a superior adhesive and a more flexible pad would likely be better adapted to enable its future use in equine practice.

Intracranial pressure monitoring in normal dogs using subdural and intraparenchymal miniature strain-gauge transducers.

BACKGROUND: Monitoring of intracranial pressure (ICP) is a critical component in the management of intracranial hypertension. Safety, efficacy, and optimal location of microsensor devices have not been defined in dogs. HYPOTHESIS/OBJECTIVE: Assessment of ICP using a microsensor transducer is feasible in anesthetized and conscious animals and is independent of transducer location. Intraparenchymal transducer placement is associated with more adverse effects. ANIMALS: Seven adult, bred-for-research dogs. METHODS: In a prospective investigational study, microsensor ICP transducers were inserted into subdural and intraparenchymal locations at defined rostral or caudal locations within the rostrotentorial compartment under general anesthesia. Mean arterial pressure and ICP were measured continuously during physiological maneuvers, and for 20 hours after anesthesia. RESULTS: Baseline mean ± SD values for ICP and cerebral perfusion pressure were 7.2 ± 2.3 and 78.9 ± 7.6 mm Hg, respectively. Catheter position did not have a significant effect on ICP measurements. There was significant variation from baseline ICP accompanying physiological maneuvers (P < .001) and with normal activities, especially with changes in head position (P < .001). Pathological sequelae were more evident after intraparenchymal versus subdural placement. CONCLUSIONS AND CLINICAL IMPORTANCE: Use of a microsensor ICP transducer was technically straightforward and provided ICP measurements within previously reported reference ranges. Results support the use of an accessible dorsal location and subdural positioning. Transient fluctuations in ICP are normal events in conscious dogs and large variations associated with head position should be accounted for when evaluating animals with intracranial hypertension.

Upper rate behavior in six dogs with dual-chamber pacemakers.

INTRODUCTION: This report provides clinical examples of upper rate behavior in dogs with dual-chamber pacemakers, with suggestions for programming alterations to avoid detrimental upper rate behavior. ANIMALS: Six dogs with dual-chamber pacemakers displaying upper rate behavior at upper atrial tracking rates. METHODS: Medical records of dogs with dual-chamber pacemakers with evidence of upper rate behavior were reviewed retrospectively from two institutions. Two of the six dogs were followed prospectively, and 24 h Holter monitors were placed to evaluate upper rate behavior correlated to programming settings. RESULTS: Pacemaker Wenckebach or 2:1 atrioventricular block was documented in four of six dogs, and automatic mode switch was documented in two of six dogs. Twenty-four-hour Holter monitors placed on two dogs after pacemaker optimization documented a pacemaker Wenckebach window at increased atrial rates with neither dog reaching their respective 2:1 block point throughout the recording period. CONCLUSIONS: Clinicians who implant dual-chamber pacemakers should be aware of upper rate behavior in animal species with high heart rates. Optimal programming of dual-chamber pacemakers can be achieved by selecting programmed timing intervals to limit deleterious upper rate behavior and create a more physiologic ventricular response at maximum tracking rates.

Canine Vertebral Screw and Rod Fixation System: Design and Mechanical Testing.

OBJECTIVES: To develop the canine vertebral screw and rod fixation system (CVSRF) and to compare the biomechanical properties between CVSRF and the screw and polymethylmethacrylate (Screw-PMMA) technique for internal fixation of the vertebral column in dogs. METHODS: The CVSRF consisted of vertebral screws with monoaxial side-loaded head, rods and specific inner screws connecting rod to the screw head. The CVSRF prototype was made from titanium alloy and manufactured by the rapid prototype machine. Vertebrectomy models were simulated by ultra-high-molecular-weight polyethylene blocks and tested with the CVSRF system (n = 8) and the Screw-PMMA technique (n = 8). The models were developed according to the American Society for Testing and Materials (ASTM F-1717-04). The biomechanical parameters were the compressive bending yield load, the compressive bending stiffness, the compressive ultimate load and the load displacement curve. RESULTS: The mean values of the compressive bending yield load, compressive bending stiffness and compressive ultimate load of the CVSRF were significantly higher than those of the Screw-PMMA technique (p < 0.01). The load displacement curve of the CVSRF showed higher rigidity and durability than that of the Screw-PMMA technique. CLINICAL SIGNIFICANCE: This mechanical study indicated that the CVSRF system can be used for canine vertebral stabilization and the biomechanical properties were better than those for the Screw-PMMA device.

An International Survey of Approaches to Chair Restraint of Nonhuman Primates.

Specifically designed restraint chairs are the preferred method of restraint for research studies that require NHP to sit in place for sustained periods of time. In light of increasing emphasis on refinement of restraint to improve animal wellbeing, it is important to have a better understanding of this potentially stressful procedure. Although chair restraint is used internationally, very little published information is available on this subject. We developed a survey to obtain an overview of equipment, procedures, and plans for improvement regarding chair restraint. We received 101 responses from people working in academic, government, contract research, and pharmaceutical laboratories within the Americas, Europe and Asia. Findings indicate that the majority of laboratories using restraint chairs work with macaque species. Restraint chairs are used for a wide range of procedures, including cognitive testing, recording neuronal activity, functional MRI, intravenous infusion, and blood sampling. Approximately 2/3 of laboratories use an enclosed 'box chair,' which the animal is trained to enter and then to extend its head through an opening on the top of the chair; the remaining one third of laboratories use an 'open chair' design, in which manual handling or the pole-and-collar system is used to transfer and secure the animal into the chair. Respondents reported that when selecting the type of chair to use, they considered comfort for the animal, ease of use, and the ability to adjust fit between animals of different sizes. Various training methods and timeframes are used to prepare macaques for restraint chair procedures. Several laboratories are incorporating greater use of positive reinforcement training. The community that uses these restraint procedures needs to work together to define best practice; our survey results can help in that effort.

An easy to produce and economical three-dimensional brain phantom for stereotactic computed tomographic-guided brain biopsy training in the dog.

OBJECTIVE: To develop and validate a three-dimensional (3D) brain phantom that can be incorporated into existing stereotactic headframes to simulate stereotactic brain biopsy (SBB) and train veterinary surgeons. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Canine brain phantoms were fabricated from osteological skull specimens, agarose brain parenchyma, and cheddar and mozzarella cheese molds (simulating meningiomas and gliomas). METHODS: The neuroradiologic and viscoelastic properties of phantoms were quantified with computed tomography (CT) and oscillatory compression tests, respectively. Phantoms were validated by experienced and novice operators performing SBB on phantoms containing randomly placed, focal targets. Target yield and needle placement error (NPE) were compared between operators. RESULTS: Phantoms were produced in <4 hours, at an average cost of $92. The CT appearances of the phantom skull, agarose, and cheese components approximated the in vivo features of skull, brain parenchyma, and contrast-enhancing tumors of meningeal and glial origin, respectively. The complex moduli of the agarose and cheeses were comparable to the viscoelastic properties of in vivo brain tissues and brain tumors. The overall diagnostic yield of SBB was 88%. Although NPE did not differ between novice (median 3.68 mm; range, 1.46-14.54 mm) and experienced surgeons (median 1.17 mm, range, 0.78-1.58 mm), our results support the relevance of the learning curve associated with the SBB procedure. CONCLUSION: This 3D phantom replicates anatomical, CT, and tactile features of brain tissues and tumors and can be used to develop the technical skills required to perform SBB.

Rehabilitative Soft Exoskeleton for Rodents.

Robotic exoskeletons provide programmable, consistent and controllable active therapeutic assistance to patients with neurological disorders. Here we introduce a prototype and preliminary experimental evaluation of a rehabilitative gait exoskeleton that enables compliant yet effective manipulation of the fragile limbs of rats. To assist the displacements of the lower limbs without impeding natural gait movements, we designed and fabricated soft pneumatic actuators (SPAs). The exoskeleton integrates two customizable SPAs that are attached to a limb. This configuration enables a 1 N force load, a range of motion exceeding 80 mm in the major axis, and speed of actuation reaching two gait cycles/s. Preliminary experiments in rats with spinal cord injury validated the basic features of the exoskeleton. We propose strategies to improve the performance of the robot and discuss the potential of SPAs for the design of other wearable interfaces.

Validation of a Portable Low-Power Deep Brain Stimulation Device Through Anxiolytic Effects in a Laboratory Rat Model.

Deep brain stimulation (DBS) devices deliver electrical pulses to neural tissue through an electrode. To study the mechanisms and therapeutic benefits of deep brain stimulation, murine preclinical research is necessary. However, conducting naturalistic long-term, uninterrupted animal behavioral experiments can be difficult with bench-top systems. The reduction of size, weight, power consumption, and cost of DBS devices can assist the progress of this research in animal studies. A low power, low weight, miniature DBS device is presented in this paper. This device consists of electronic hardware and software components including a low-power microcontroller, an adjustable current source, an n-channel metal-oxide-semiconductor field-effect transistor, a coin-cell battery, electrode wires and a software program to operate the device. Evaluation of the performance of the device in terms of battery lifetime and device functionality through bench and in vivo tests was conducted. The bench test revealed that this device can deliver continuous stimulation current pulses of strength [Formula: see text], width [Formula: see text], and frequency 130 Hz for over 22 days. The in vivo tests demonstrated that chronic stimulation of the nucleus accumbens (NAc) with this device significantly increased psychomotor activity, together with a dramatic reduction in anxiety-like behavior in the elevated zero-maze test.

Revision of a BFX total hip replacement stem using a Kyon stem and a head adaptor in two dogs.

OBJECTIVE: To report revision of BFX cementless press-fit stem loosening with a Kyon cementless stem and a head adaptor in two dogs. METHODS: Total hip arthroplasty stem revision was performed in two dogs with loosening of a previously implanted Biomedtrix press-fit BFX stem. Both dogs had a well-integrated BFX cup and single stage revision was performed using a standard Kyon stem and a head adaptor in order to couple with a 17 mm head and maintain the BFX cup. RESULTS: Revisions resulted in a stable functional prosthesis with successful bone integration at the one-year postoperative re-evaluation. CONCLUSIONS: Use of a Kyon stem with a head adaptor may be a successful option to provide immediate stem stability for revision of a loosened BFX stem with a properly osseointegrated cup.

Advances in Laparoscopic Surgery.

Recently, a new platform of abdominal access, called single-port surgery, has emerged in human and veterinary laparoscopy. The single-port platform enables all laparoscopic instruments, including the telescope, to pass individually through the same abdominal incision. Recently, there have been several published reports documenting the efficacy and safety of single-port procedures in veterinary patients. This article discusses the common single-port devices and instrumentation, as well as procedures now routinely offered in veterinary minimally invasive surgery.

Advances in Flexible Endoscopy.

Flexible endoscopy, a minimally invasive diagnostic and potentially therapeutic tool, has become more available over the past decades. A fiberscope is used to visualize the lumen of the area of interest and collect tissue or fluid samples for evaluation. Samples can be submitted for histopathology, cytologic analysis, and bacterial culture. Flexible endoscopy is being investigated. This article provides a brief review of equipment and basic flexible endoscopy followed by an overview of advanced flexible endoscopic procedures that focuses on the gastrointestinal tract. The procedures included here may become more readily available and improve diagnosis and treatment.

Analysis of factors affecting milking claw vacuum levels using a simulated milking device.

Bovine mastitis is typically caused by microbial infection of the udder, but the factors responsible for this condition are varied. One potential cause is the milking system, and although previous studies have investigated various methods for inspecting these devices, most have not assessed methods for evaluating the milking units. With this in mind, we analyzed the factors that affect the vacuum inside the milking claw by using a simulated milking device and by measuring milking claw vacuum when adjusting the flow rate in five stages. The factors analyzed in each milking system were the vacuum pressure settings (high and low line system) , milk tube length (200-328 cm), aperture diameter (14-22.2 mm), constricted aperture diameter (12 mm), tubing configurations, lift formation (0-80 cm), claw type (bottom and top flow) and use or non-use of a milk sampler. The study findings demonstrated that all of these variables had a significant impact on claw vacuum and suggest that a diagnostic method using a simulated milking device should be considered when inspecting modern milking systems.

Design of an endovascular morcellator for the surgical treatment of equine Cushing's disease.

BACKGROUND: A new paradigm of surgical treatment of equine Cushing's disease has been developed using the vascular system combined with a flexible morcellation instrument to reach the pituitary gland. OBJECTIVE: The goal was twofold: (1) to design, prototype, and test an instrument that can reach the pituitary gland using the vascular system unique to equids and (2) to test the feasibility of the endovascular approach. ANIMALS AND METHODS: The morcellator consists of a radial rotating cutting blade for tissue resection, a flexible shaft incorporating a cable drive for flexible actuation, and central morcellated tissue transportation lumen. The morcellator prototype was tested on a horse's cadaver head for the validation of the cutting blade design, actuator design, and feasibility of the endovascular approach. RESULTS: The overall assembled length of the morcellator tip was 13.9 mm, allowing for non-traumatic steering through the vascular system from the proximal end. The radially rotating cutting blade (barrel of Ø 4 and 4.4 mm width) incorporated multiple cutting edges to deliver the action force during resection and provides the necessary grasping force to draw the tissue towards the second cutting edge of the morcellator incorporated inside the blunted cuboidal static tip element (5 mm square and wall-thickness of 0.3 mm). In the tests, the morcellator was successfully guided towards the pituitary and managed to sample pituitary tissue. CONCLUSION AND CLINICAL IMPORTANCE: Continued development of the prototype and the endovascular approach may in time improve the outcome and quality of life of horses suffering from Cushing's disease.

Validation of an effective, easy-to-make hemostasis simulator.

The purpose of this study is to describe the construction method of a cost-effective, easy-to-make hemostasis simulator and to compare its effectiveness as a training tool to cadaver training. The simulator is made of materials commonly found in hospitals and clinics. These include a column manometer, a 500-ml saline bag, two intravenous fluid lines, a three-way stopcock, and a 6-mm-diameter Penrose drain. The device was tested on 10 final-year veterinary students. All participants tied 40 knots on the simulator and 40 knots on equine jejunal arteries sourced from a local abattoir. They were then asked to fill out a questionnaire comparing both methods. Participants assigned an overall assessment median score of 8.5/10 to the simulator and of 6.2/10 to cadaver practice. The simulator provided reliable haptic feedback, giving trainees a lifelike feel very close to that experienced when actually closing a blood vessel. In addition, it was effective in objectively evaluating students' ability to place ligatures on vessels. After adequate training, students' skills had significantly improved, alongside their confidence in placing hemostatic sutures. This proves our model is also useful in teaching basic open-surgery skills. Finally, its low production cost makes it ideally suited for self-practice.

Development of visible and NIR imaging equipment for small animals with smart pad.

The portable visible and near-infrared (NIR) imaging equipment for a pre-clinical test with small animals was designed and developed in this paper. The developed equipment is composed of a CCD camera, a focusing lens, an objective lens, a NIR band pass filter and a NIR filter driving motor. An NIR ray is mainly used for imaging equipment because it has high light penetration depth in biological tissue. Therefore, NIR fluorescent agents are available for chemical conjugation to targeting molecules in vivo. This equipment can provide a visible image, NIR image and merged image simultaneously. A communication system was specifically established to check obtained images through a smart pad in real time. It is less dependent on space and time than the conventional system.

Make it spin: individual trapping of sperm for analysis and recovery using micro-contact printing.

In this article, we describe the development of a high throughput platform to spatially manipulate viable sperm for motility measurements and recovery of the best single sperm for fertilization purposes. Micro-contact printing was used to pattern islands of adhesive proteins (fibronectin) separated by sperm repellent species (Pluronic acid F-127) on commercially available polystyrene substrates. Following washing, arrays of viable single sperm were captured onto the islands demonstrating for the first time that sperm can be trapped by micro-contact printing with patterning efficiency of 90% while retaining 100% viability. These were then subjected to motility analysis whilst remaining spatially confined to the islands. Single sperm motility was assessed (n = 37) by software analysis measuring the number of rotations per second (degrees s⁻¹). The assignment of array coordinates allows the more active single sperm to be easily identified and recovered by a simple micromanipulator pipette aspiration step with automated possibility for assisted reproductive technologies or further quality correlation analysis. Taken together, we show for the first time a technique to simultaneously screen thousands of viable single sperm for motility assessment while retaining the ability for single species recovery for enhanced fertilization purposes.

In vivo biomechanical evaluation of a novel angle-stable interlocking nail design in a canine tibial fracture model.

OBJECTIVE: To compare clinical outcome and callus biomechanical properties of a novel angle stable interlocking nail (AS-ILN) and a 6 mm bolted standard ILN (ILN6b) in a canine tibial fracture model. STUDY DESIGN: Experimental in vivo study. ANIMALS: Purpose-bred hounds (n = 11). METHODS: A 5 mm mid-diaphyseal tibial ostectomy was stabilized with an AS-ILN (n = 6) or an ILN6b (n = 5). Orthopedic examinations and radiographs were performed every other week until clinical union (18 weeks). Paired tibiae were tested in torsion until failure. Callus torsional strength and toughness were statistically compared and failure mode described. Total and cortical callus volumes were computed and statistically compared from CT slices of the original ostectomy gap. Statistical significance was set at P < .05 RESULTS: From 4 to 8 weeks, lameness was less pronounced in AS-ILN than ILN6b dogs (P < .05). Clinical union was reached in all AS-ILN dogs by 10 weeks and in 3/5 ILN6b dogs at 18 weeks. Callus mechanical properties were significantly greater in AS-ILN than ILN6b specimens by 77% (failure torque) and 166% (toughness). Failure occurred by acute spiral (control and AS-ILN) or progressive transverse fractures (ILN6b). Cortical callus volume was 111% greater in AS-ILN than ILN6b specimens (P < .05). CONCLUSIONS: Earlier functional recovery, callus strength and remodeling suggest that the AS-ILN provides a postoperative biomechanical environment more conducive to bone healing than a comparable standard ILN.