Mechanical Evaluation of the Equine Laryngoplasty

Abstract

Mechanical evaluation of the equine laryngoplasty. Experimental. Cadaveric cricoid (n=36) and arytenoid (46) cartilages. Arytenoid and cricoid cartilage specimens were embedded for testing. Suture material (2 Ethilon, 5 Ethibond, or 5 Fiberwire) was inserted simulating laryngoplasty procedures. Constructs were evaluated in single or cyclic loading. Single cycle tests recorded load at failure and stiffness. Cyclical tests recorded displacement after 10,000 cycles. ANOVA and t-tests were used (significance P<.05). The arytenoid Ethibond (241.10+/-47.67 N) constructs were stronger in single cycle than Ethilon (133.85+/-27.89 N) and Fiberwire (142.67+/-32.40 N). The cricoid Ethibond (220.39+/-49.11 N) constructs were stronger than Ethilon (171.93+/-21.19). The stiffness of Ethilon constructs was lower in both the arytenoid and cricoid compared with Ethibond and Fiberwire. The arytenoids failed at a lower load than the cricoids for Ethilon and Fiberwire but not Ethibond constructs. In cyclic testing complete failure of either cartilage did not occur. Arytenoid Ethibond constructs (0.43+/-0.21 mm) had less distraction than Ethilon (0.92+/-0.41 mm) and a trend for less compared with Fiberwire (0.83+/-0.43 mm; P=.0513). Cricoid Ethibond constructs (0.45+/-0.18 mm) had less distraction compared with Ethilon (1.04+/-0.30 mm) and Fiberwire (0.97+/-0.45 mm). Ethibond was superior to Ethilon and Fiberwire constructs in vitro. Abduction loss after laryngoplasty is a common complication. The results of this study suggest that the use of Ethibond should minimize abduction loss after surgery relative to the other materials tested.