Laser vocal cordectomy fails to effectively reduce respiratory noise in horses with laryngeal hemiplegia

• Published in: Veterinary surgery Vol. 34; no. 3; pp. 247 - 252
• Main Authors: Brown, J.A, Derksen, F.J, Stick, J.A, Hartmann, W.M, Robinson, N.E
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Inc 01.05.2005; Blackwell Publishing Ltd
• Subjects: Animal diseases; Animals; chordectomy; exercise; Female; horse; horse diseases; Horse Diseases - physiopathology; Horse Diseases - surgery; Horses; laryngeal hemiplegia; laser vocal chordectomy; laser vocal cordectomy; Lasers; Male; Noise; Physical Conditioning, Animal; recurrent laryngeal neuropathy; Respiratory Function Tests - veterinary; respiratory noise; Respiratory Sounds; Respiratory system; respiratory tract diseases; sounds; Surgery; therapeutics; Throat; Treatment Outcome; upper airway; vocal chord; Vocal Cord Paralysis - surgery; Vocal Cord Paralysis - veterinary; Vocal Cords - physiopathology; Vocal Cords - surgery; vocalization
• ISSN: 0161-3499; 1532-950X
• DOI: 10.1111/j.1532-950X.2005.00037.x

Objective— To report the effect of unilateral laser vocal cordectomy on respiratory noise and airway function in horses with experimentally induced laryngeal hemiplegia (LH). Study Design— Experimental study. Animals— Six Standardbred horses without upper airway abnormities at rest or during high‐speed treadmill exercise. Methods— Respiratory sounds and inspiratory trans‐upper airway pressure (PUi) were measured before (baseline) and 14 days after induction of LH by left recurrent laryngeal neurectomy, and again 30, 60, 90, and 120 days after endoscopically assisted laser cordectomy of the left vocal cord. Data were collected with the horses exercising on a treadmill at a speed producing maximum heart rate (HRmax). Results— In horses exercising at HRmax, induction of LH caused a significant increase in PUi, sound level (SL), and the sound intensity of formant 2 (F2) and 3 (F3). The sound intensity of formant 1 (F1) was unaffected by induction of LH. Laser vocal cordectomy had no effect on SL, or on the sound intensity of F1 and F3. At 30, 60, 90, and 120 days after surgery, PUi and the sound intensity of F2 were significantly reduced, but these variables remained significantly different from baseline values. Conclusions— Unilateral laser vocal cordectomy did not effectively improve upper airway noise in horses with LH. The procedure decreased upper airway obstruction to the same degree as bilateral ventriculocordectomy. Clinical Relevance— Currently, laser vocal cordectomy cannot be recommended for the treatment of upper airway noise in horses with LH.