Long-term maintenance of arytenoid cartilage abduction and stability during exercise after laryngoplasty in 33 horses

<b>Objectives</b> To (1) assess long-term maintenance of arytenoid cartilage abduction (ACA) after laryngoplasty (LP); and (2) correlate the residual grade of ACA and postoperative abductory loss with arytenoid cartilage stability (ACS) during exercise.<p></p> <b>Study Design</b> Case series.<p></p> <b>Animals</b> Horses re-examined after laryngoplasty (n = 33).<p></p> <b>Methods</b> Of 89 LP horses (2005–2010), 33 had historic ACA data available and upper airway endoscopy at rest and during over-ground exercise (mean, 33 months; range, 4–71 months) after surgery. ACA grade at 1 and 6 weeks postoperatively were correlated to long-term ACA grade. Effects of long-term ACA grade and magnitude of postoperative abductory loss on ACS during exercise were investigated.<p></p> <b>Results</b> Median ACA grade at 1 week (n = 33) was 2, reducing to grade 3 by week 6 (n = 16). Grade 3 abduction was maintained in the long-term. Correlation between ACA at 1 week and the long-term was poor (ρ = .43, P = .1), but there was good correlation between week 6 and long-term (ρ = .89, P < .001). Arytenoid cartilage instability was observed during exercise in 7/33 of horses, and not significantly associated with the ACA grade (P = .50), or the number of grades of ACA lost (P = .64).<p></p> <b>Conclusions</b> Limited abductory loss occurs after 6 weeks postoperatively. Resting ACA grade was not a useful predictor of ACS during exercise.<p></p&gt