Clinical Assistant Professor University of Illinois College of Veterinary Medicine
Cadaveric larynges are commonly used to evaluate the laryngoplasty (LP) procedure. The purpose of this study was to assess the effect of repeated freezing and thawing on the suture pull-out strength in equine arytenoid and cricoid cartilages. Bilateral LP constructs were created using a standard LP technique in ten grossly normal equine cadaveric larynges. One hemi-larynx was randomly allocated to the single freeze and thaw group and the other allocated to the repeated freeze and thaw (three complete cycles) group. The suture ends of each LP construct were attached to a load frame and subjected to monotonic loading until construct failure. Mean load (N) and displacement (mm) at LP failure were compared between groups. All constructs failed by suture pull-through the arytenoid cartilage. The mean load at failure was similar between groups (118.9 ± 25.5 N in the single freeze and thaw group and 113.4 ± 20.5 N in the repeated freeze and thaw group, p = 0.62). The mean displacement at failure was similar between groups (54.4 ± 15.1 mm in the single freeze and thaw group and 54.4 ± 15.4 mm in the repeated freeze and thaw group, p = 0.99). Limitations of the study include only one model of repeated freeze-thaw cycles being evaluated with no fresh specimens as a comparison group. Laryngeal specimens that have been subjected to repeated freezing and thawing can be utilized in the experimental evaluation of LP procedures because there is no alteration of the suture pull-out strength of the relevant cartilages.
