Effects of bilateral arytenoid cartilage stenting on canine laryngeal resistance ex vivo

Abstract

Objective: To evaluate the effect of Nitinol stents for bilateral arytenoid lateralization on canine laryngeal resistance.

Study design: Ex vivo experimental study.

Animals: Canine cadaver larynges (n=7).

Methods: Laryngeal resistance was calculated in all specimens with the epiglottis in open and closed positions. Bilateral arytenoid stenting was performed, rima glottidis width measured, and laryngeal resistance calculated. The effects of stenting on laryngeal resistance were evaluated by repeated measures ANOVA.

Results: Calculated laryngeal resistance in the 3 stented groups, 2 cm (0.034±0.059 cmH(2) O/L/s), 3 cm (0.034±0.059 cmH(2) O/L/s), and 4 cm (0.034±0.059 cm H(2) O/L/s), was significantly decreased versus the control (unstented) group (0.947±0.624 cmH(2) O/L/s; P=.0098) with an epiglottis in the normal position. Calculated laryngeal resistance in the 3 stented groups, 2 cm (43.407±17.348 cm H(2) O/L/s), 3 cm (70.659±34.705 cmH(2) O/L/s), and 4 cm (92.637±44.509 cm H(2) O/L/s), was significantly increased versus the control (unstented) group (29.561±14.499 cm H(2) O/L/s) (P=.0185) with an epiglottis in the closed position. The width of the rima glottidis correlated with the size of the stent (r=0.95, P<.001).

Conclusions: Bilateral arytenoid stenting significantly reduced calculated laryngeal resistance with an open epiglottis. Stenting resulted in a significant increase in laryngeal resistance versus the control with a closed epiglottis. Use of bilateral arytenoid stenting in clinical cases of laryngeal paralysis may provide an adequate decrease in open-epiglottis airway resistance to alleviate clinical signs, while increasing closed-epiglottis airway resistance. This could potentially lead to a decrease in the risk of postoperative aspiration pneumonia.