Evaluation of two unilateral laryngoplasty techniques and their effect on arytenoid cartilage abduction in cats.

Abstract

The aim of this study was to evaluate two unilateral laryngoplasty (arytenoid lateralisation) techniques for use in the surgical management of laryngeal paralysis in cats. Left cricoarytenoid abduction (lateralisation) was performed in 20 ex vivo cat larynges; 10 following complete cricoarytenoid disarticulation (group LAA-dis) and 10 following no cricoarytenoid disarticulation (group LAA-nodis). For both groups, left arytenoid abduction (LAA) was measured in the resting and postoperative larynges using image analysis software. Measurements were evaluated using the Mann-Whitney U-test. For both groups, dorsal images of the postoperative larynges were assessed visually for evidence of epiglottic coverage of the entrance to the larynx. The mean percentage increase in LAA was 311.5% and 199.4% (P <0.006) for group LAA-dis (complete cricoarytenoid disarticulation) and group LAA-nodis (no cricoarytenoid disarticulation), respectively. In both groups, there was no evidence of a lack of epiglottic coverage of the entrance of the larynx for any of the postoperative larynges. Placement of a single, tensioned suture between the muscular process of the left arytenoid cartilage and the caudolateral aspect of the ipsilateral cricoid cartilage (unilateral cricoarytenoid lateralisation) resulted in abduction of the left arytenoid cartilage and a corresponding increase in the area of the rima glottidis on the operated side. The clinical significance of the difference in outcome between left cricoarytenoid abduction following complete cricoarytenoid disarticulation and abduction following no cricoarytenoid disarticulation remains unclear, and both might be considered appropriate for the surgical management of laryngeal paralysis in the cat.