Evaluation of a novel, low-cost, 3D printed video laryngoscope with borescope in anesthetized Beagle dogs.

OBJECTIVE: To develop and evaluate a low-cost three-dimensional (3D)-printed video laryngoscope (VLVET) for use with a commercial borescope. STUDY DESIGN: Instrument development and pilot study. ANIMALS: A total of six adult male Beagle dogs. METHODS: The VLVET consisted of a laryngoscope handle and a Miller-type blade, and a detachable camera holder that attached to various locations along the blade. The laryngoscope and camera holder were 3D-printed using black polylactic acid filament. Dogs were premedicated with intravenous (IV) medetomidine (15 µg kg-1) and anesthesia induced with IV alfaxalone (1.5 mg kg-1). The VLVET, combined with a borescope, was used for laryngeal visualization and intubation. Performance was evaluated by comparing direct and video-assisted views in sternal recumbency. The borescope camera was sequentially positioned at 2, 4, 6, 8 and 10 cm from the blade tip (distanceLARYNX-CAM), which was placed on the epiglottis during intubation or laryngoscopy. At the 10 cm distanceLARYNX-CAM, laryngeal visualization was sequentially scored at inter-incisor gaps of 10, 8, 6, 4 and 2 cm. Laryngeal visualization scores (0-3 range, with 0 = obstructed and 3 = unobstructed views) were statistically analyzed using the Friedman's test. RESULTS: Under direct visualization, the 2 cm distanceLARYNX-CAM had a significantly lower score compared with all other distanceLARYNX-CAM (all p = 0.014) because the view was obstructed by the camera holder and borescope camera. With both direct and camera-assisted views, visualization scores were higher at inter-incisor gaps ≥ 4 cm compared with 2 cm (all p < 0.05). CONCLUSIONS AND CLINICAL RELEVANCE: During laryngoscopy and intubation, the VLVET and borescope facilitated both direct and video laryngoscopy at distanceLARYNX-CAM in Beagle dogs when inter-incisor gaps were ≥ 4 cm.

The use of a plastic guide improves the safety and reduces the duration of endotracheal intubation in the pig.

The successful endotracheal intubation of pigs using the standard orotracheal method is challenging and technically difficult, because of the pig's oral anatomy and the presence of excess tissue in the oropharyngeal region. Hence, the operator, who is usually an anesthetist, requires extensive training in order to successfully perform the procedure in pigs. In this report, we describe a safe and quick method of successful endotracheal intubation in the pig using an 80-cm blunt-tipped plastic vascular catheter, when the pig is placed in ventral recumbency. Specifically, the use of this plastic guide wire shortened the duration of the procedure and reduced the risks of the procedure. Since the use of the guide wire also improves the ease of the procedure, its use will also enable inexperienced operators to perform successful first-time endotracheal intubation of pigs without causing injury.

Evaluation of a laryngoscope and a rigid endoscope for the examination of the oral cavity of small mammals.

The oral cavities of 65 rabbits, 35 chinchillas, 38 guinea pigs, 19 degus and 13 prairie dogs suffering from a lack of appetite, hypersalivation, moist dermatitis, swelling of the lower jaw or mild exophthalmos were examined with a paediatric laryngoscope and rigid endoscope. The laryngoscope was safe and satisfactory for a preliminary examination, but changes in the less accessible caudal parts of the cavity could not be identified precisely. A rigid endoscope with 30 degrees optics made it possible to examine all parts of the oral cavity and oropharynx, and make detailed observations of surface lesions on the premolar and molar teeth and the mucosal surface of the gingiva, tongue and hard palate; endoscopy with 70 degrees optics provided an excellent view of the occlusal tooth surfaces, tooth crowns, and buccal mucosa. The collection of biopsy samples, the removal of foreign objects and the correction of malocclusions were greatly simplified by the use of the endoscope owing to the clear visualisation of the procedures, and the risk of injury was minimised. The examinations with a laryngoscope were made effectively on animals that were manually restrained, but a thorough examination with a rigid endoscope required the animals to be anaesthetised.

A laryngoscope designed for intubation of the rat.

We successfully intubated 257 rats with a laryngoscope that we designed for this purpose. Orotracheal intubation with this laryngoscope can be performed quickly and without harm to the animal. This instrument provides direct visualization of the vocal cords, allowing rapid, safe intubation of the rat. Maintenance of an adequate airway with endotracheal intubation is superior to tracheostomy for repeated experiments, and therefore this laryngoscope makes such studies easier and safer to perform.