Ex vivo evaluation of arytenoid corniculectomy, compared with three other airway interventions, performed on cadaveric equine larynges with simulated recurrent laryngeal neuropathy.

This study compares the effects, particularly laryngeal impedance, of four different surgical interventions on horse larynges with a simulated nerve disorder. Results indicated factors such as tracheal adapter diameter, individual laryngeal properties, type of intervention, and degree of laryngeal collapse affected laryngeal impedance. The study suggests that further investigation into certain procedures may be warranted, taking into account individual variations.

Objective and Methodology

• The research aimed to compare the impact on laryngeal air flow and pressure, also known as impedance, after performing arytenoid corniculectomy (COR) versus three other airway interventions which included left-sided laryngoplasty with ipsilateral ventriculocordectomy (LLP), LLP combined with COR (LLPCOR), and partial arytenoidectomy (PA).
• These procedures were performed on 28 cadaveric equine larynges, replicating the condition of left recurrent laryngeal neuropathy (RLN), a nerve disorder common in horses.
• The researchers used a box model construct that mimicked upper airway flow mechanics at the time of peak exercise in horses.
• They evaluated each larynx in states of simulated left RLN alone and with the intervention procedures in a specific order: LLP, LLPCOR, COR, and PA.

Results

• Impedance was calculated from changes in airflow and pressure, and the calculations for each larynx were compared between states.
• The study found that diameter of the tracheal adapter, individual larynx properties, type of intervention, and degree of laryngeal collapse affected the impedance.
• The interventions LLP and LLPCOR were found to have the least impedance, whereas the COR and PA interventions did not show a substantial difference from the state simulating left RLN.
• The residual intraclass correlation of the model used in the study was 27.6%.

Conclusions

• Though the impedance was found to be higher when dealing with simulated left RLN in the COR intervention than in the LLP intervention, the clinical success of the PA intervention in treating RLN in horses, coupled with the similar results achieved by the COR and PA interventions in the study, suggest that the use of COR for future investigations is justified.
• The residual interclass correlation noted that individual variation in laryngeal impedance might have a clinical effect, implying that each horse’s unique laryngeal characteristics should be taken into consideration when deciding on a surgical intervention.