Overground endoscopic findings and respiratory sound analysis in horses with recurrent laryngeal neuropathy after unilateral laser ventriculocordectomy.
Authors: Barakzai S Z, Wells J, Parkin T D H, Cramp P
Journal: Equine veterinary journal
Summary
# Editorial Summary: Recurrent Laryngeal Neuropathy and Laser Ventriculocordectomy Unilateral laser ventriculocordectomy is commonly performed to improve airflow in horses with recurrent laryngeal neuropathy (RLN), yet little objective evidence exists evaluating its effectiveness in naturally affected horses. Barakzai and colleagues prospectively examined ten RLN-affected horses (three grade B, seven grade C) using overground endoscopy and concurrent respiratory sound analysis before surgery and 6–8 weeks post-operatively, quantifying changes in laryngeal geometry (left-to-right quotient angle and rima glottidis area ratio) alongside formant analysis of recorded respiratory noise. Whilst post-operative sound analysis revealed a significant reduction in energy within the F2 formant (P = 0.05), the beneficial endoscopic improvements were heavily skewed towards grade B horses; notably, 6 of 7 grade C horses retained bilateral vocal fold collapse and 5 of 7 continued to display right-sided medial deviation of the ary-epiglottic fold despite successful left-sided surgery. These findings suggest that unilateral ventriculocordectomy delivers meaningful functional benefit in grade B cases, but grade C horses—particularly those with bilateral vocal fold collapse or concurrent medial deviation—may benefit more from bilateral procedures or supplementary interventions such as right ary-epiglottic fold resection or laryngoplasty. Practitioners should therefore consider pre-operative dynamic assessment in grade C horses to identify concurrent obstructive pathology that may require combined surgical approaches for optimal outcomes.
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Practical Takeaways
- •Unilateral laser ventriculocordectomy is an effective surgical option for grade B RLN cases with marked noise reduction documented objectively
- •Grade C horses with bilateral laryngeal obstructions (vocal fold collapse + ary-epiglottic fold deviation) require more aggressive surgical intervention than unilateral ventriculocordectomy alone—consider bilateral procedures or additional techniques
- •Continued respiratory noise post-operatively in grade C horses indicates unaddressed dynamic obstructions that may require right-sided vocal fold resection and/or laryngoplasty
Key Findings
- •Unilateral laser ventriculocordectomy produced significant reduction in energy in formant F2 (P=0.05) post-operatively in RLN-affected horses
- •Grade B horses (3/10) showed no other endoscopic dynamic abnormalities post-operatively
- •Grade C horses (7/10) retained right-sided vocal fold collapse and medial deviation of ary-epiglottic fold post-operatively despite unilateral left-sided surgery
- •Unilateral ventriculocordectomy alone was insufficient for grade C horses with bilateral dynamic obstructions