Biomechanical evaluation of modified laryngoplasty by use of a toggle technique for stabilization of arytenoid cartilage in specimens obtained from equine cadavers.

OBJECTIVE To biomechanically compare modified and standard laryngoplasty constructs in monotonic load to failure and cyclic loading. SAMPLES 41 equine cadaveric larynges. PROCEDURES Laryngoplasty constructs were created by use of a standard technique on one side and a modified technique (with a toggle to anchor suture to the arytenoid cartilage) on the other side. For monotonic loading, laryngoplasty constructs were prepared and suture ends attached to a load frame; constructs then were loaded until mechanical failure. Mean load at failure and failure modes were compared between constructs. For cyclic loading, arytenoid cartilages were maximally abducted and constructs were circumferentially loaded for 10,000 cycles. Loss of arytenoid abduction was evaluated every 500 cycles with a subjective grading scale and objective change in rima glottidis cross-sectional area. RESULTS In monotonic loading, modified laryngoplasty constructs failed at a significantly higher mean ± SD load (191 ± 29 N) than did standard laryngoplasty constructs (91 ± 44 N). None of the modified laryngoplasty constructs failed by suture pull-through of the muscular process of the arytenoid cartilage, whereas most of the standard laryngoplasty constructs failed in that manner. In cyclic testing, 11 of 20 standard laryngoplasty constructs failed or achieved Dixon grade 3 abduction, whereas 0 of 20 modified laryngoplasty constructs failed. Modified laryngoplasty constructs lost significantly less rima glottidis cross-sectional area in circumferential testing, compared with loss for standard laryngoplasty constructs. CONCLUSIONS AND CLINICAL RELEVANCE The modified laryngoplasty technique was biomechanically superior to the standard laryngoplasty technique in this ex vivo study.