Association of treadmill upper airway endoscopic evaluation with results of ultrasonography and resting upper airway endoscopic evaluation.

This research evaluates the effectiveness of laryngeal ultrasonography in diagnosing recurrent laryngeal neuropathy in horses, compared to traditional methods of upper airway endoscopy. It concludes that laryngeal ultrasonography is a valuable addition to the diagnostic toolkit, demonstrating high accuracy in diagnosing abnormal arytenoid movement in horses.

Research Objectives

• The study aimed to evaluate the efficacy of laryngeal ultrasonography in diagnosing recurrent laryngeal neuropathy in horses.
• The researchers hypothesized that horses with abnormal arytenoid movement during treadmill upper airway endoscopy would exhibit increased echogenicity of the left cricoarytenoideus lateralis muscle (CALM) and decreased size of the left CALM and vocalis, whereas those with normal arytenoid movement would have standard echogenicity and similar CALM and vocalis muscle size on both sides.
• The study further proposed that laryngeal ultrasonography would be more reliable in predicting abnormal arytenoid movement than resting endoscopy.

Methods

• The researchers examined the medical records of Thoroughbred racehorses older than 2 years that had undergone resting and treadmill upper airway endoscopy along with laryngeal ultrasonography.
• The horses’ arytenoid movement was graded during both resting and treadmill examinations.
• Ultrasonography was used to measure the relative echogenicity and cross-sectional area (CSA) of the left and right CALM and the vocalis muscle.
• Data analysis was conducted using Chi-squared tests, paired t-tests, and one-way ANOVA.

Results

• The research found that abnormal arytenoid movement was associated with an increased echogenicity of the CALM, while normal arytenoid movement was not.
• Laryngeal ultrasonography demonstrated a sensitivity of 90% and specificity of 98% in diagnosing abnormal arytenoid movement, while resting upper airway endoscopy showed a sensitivity of 80% and specificity of 81%.
• There was no difference in CSA of the left CALM and vocalis muscles between groups.

Conclusions

• The study concluded that laryngeal ultrasonography is highly accurate in diagnosing abnormally moving arytenoids.
• The research supports the inclusion of ultrasonography as a valuable diagnostic tool in assessing the equine upper airway.