Objective: To describe the technique to perform diagnostic standing scapulohumeral joint needle arthroscopy with a 1.2-mm-diameter arthroscope in horses. Study design: Experimental study. Animals: Eight thoracic limbs in phase 1 and six horses in phase 2. Methods: In phase 1, the feasibility of the technique was evaluated by using a craniolateral arthroscopic approach. An evaluation of the visible structures of the scapulohumeral joint was performed with both a needle arthroscope and a 4-mm-diameter arthroscope. In phase 2, the technique was performed in six healthy sedated horses to validate the technique in live animals and to report any complications or limitations. Results: In phase 1, joint evaluation was similar between arthroscopes and allowed complete evaluation of approximately the lateral half of the humeral head and the lateral glenoid rim. In phase 2, all joints were successfully accessed, and fluid extravasation was mild. Arthroscopic visualization was complete for the centrolateral aspect of the joint in all horses and either complete (3/6) or partial (3/6) for the craniolateral and caudolateral structures, respectively. The procedure was rapidly performed and well tolerated, and no postoperative complications occurred. Conclusion: The described technique was simple and allowed direct inspection of the scapulohumeral joint. Nonetheless, the standing nature of the technique prevents evaluation of the medial aspect of the humeral head and most of the glenoid cavity. Clinical significance: Needle arthroscopy of the scapulohumeral joint is feasible in horses and offers a diagnostic technique that may improve the surgeon's diagnostic ability for certain shoulder pathologies.

Objective To describe the technique, experience, and limitations of using a 2‐mm flexible endoscope to perform standing minimally invasive sinoscopy. Study design In phases 1 and 2, we used cadaveric heads (ex vivo). In phase 3, we used unaffected horses (in vivo). Animals Five cadaveric equine skulls in phase 1 and 10 cadaveric equine skulls in phase 2. Six horses older than 5 years in phase 3. Methods In phase 1, the specimens were used to determine the suitability of the endoscope for sinoscopy and the ideal landmarks to approach the paranasal sinuses through minisinusotomies performed with a 14 gauge needle. In phase 2, a nonblinded evaluation of the visualization of the different sinus compartments was performed, and a score was attributed to each structure. Procedures were video recorded and compared with direct visualization of the sinuses after performing frontal and maxillary flaps. In phase 3, the technique was validated in healthy horses under sedation. Results The landmarks determined in phase 1 allowed a thorough exploration of the sinuses in phases 2 and 3. Sinoscopy findings were confirmed after direct visualization of the sinuses via frontal and maxillary bone flaps in phase 2. The procedure was well tolerated by all horses. Conclusion Minimally invasive sinoscopy was readily performed without relevant complications in standing horses. A thorough evaluation of most sinus structures was obtained only using the frontal and the rostral maxillary portals. Clinical significance Minimally invasive sinoscopy offers an alternative diagnostic tool to veterinarians. A specialized endoscope and appropriate training are required to perform this minimally invasive procedure.

Peripheral airway smooth muscle (ASM) mass is increased in severe equine asthma, but no information is available on age related changes in ASM. In this study, peripheral ASM dimensions were determined in healthy horses of different ages. The thickness of the peripheral ASM layer was constant in horses of different ages, but ASM occupied a greater proportion of the inner wall area in young horses compared to older horses. This finding suggests that equine airways experience a decrease in the relative abundance of ASM with age.

Nasal conchal bulla empyema can be found in up to 20% of horses with paranasal sinus disease but remains difficult to diagnose and can result in persistent unilateral discharge before presentation. Our aim in this experimental ex vivo study was to describe two extra-nasal approaches to access the nasal conchal bullae. Six cadaveric heads were used to determine the ideal landmarks to access the dorsal and ventral conchal bullae through two rhinocenteses performed with the aid of a 14G needle and a mallet through the maxillary bone, and to access both bullae simultaneously through a 13mm diameter trephination. Both techniques were performed bilaterally. To assess correct placement of the rhinocenteses and trephination, each bulla was injected with a coloured insulating foam before performing a maxillary bone flap to inspect the bullae. Both bullae were successfully entered with the 14G needle in all instances. The nasolacrimal duct was damaged while entering the ventral conchal bulla in 3/12 approaches. Trephination of the maxillary bone allowed access to both nasal conchal bullae in all cases but one, where the portal was placed too dorsally and did not allow access to the ventral conchal bulla. The opening created with the trephine could allow the use of a small instrument such as a rongeur which could have diagnostic and therapeutic benefits. The limitations are that this was an ex vivo study and nasolacrimal duct damage could have clinical repercussions if the duct becomes obstructed after accessing the ventral conchal bulla. It was concluded that the techniques described are simple, minimally invasive and provide access to the conchal bullae for diagnostic and therapeutic purposes. Additionally, they may reduce the need for CT or laser for the diagnosis and treatment of bulla empyema.

Les sinus paranasaux du cheval sont composés de sept cavités différentes et peuvent être affectés par des maladies très diverses. Les techniques diagnostiques traditionnelles (endoscopie, radiographie, sinusoscopie) peuvent être invasives et ne permettent pas toujours d’obtenir un diagnostic précis. Des études récentes ont cherché à pallier ces défauts en développant des techniques permettant l’accès aux sinus par endoscopie depuis les cavités nasales ou encore de réaliser une sinusoscopie de manière minimalement invasive. Pour le moment, le scanner reste le meilleur outil pour diagnostiquer les maladies sinusales, en particulier pour les sinusites d’origine dentaire. L’IRM, plus couteux et plus difficile d’accès, est intéressant pour le diagnostic des tumeurs. Le traitement chirurgical des sinusites peut être difficile et comporte de nombreuses complications. Afin de diminuer le taux de morbidité, des travaux récents ont permis de mettre au point différentes techniques visant à améliorer le drainage des sinus vers les cavités nasales, limiter les risques d’hémorragies et faciliter le traitement des affections bilatérales et des fistules cutanées.