An Ex Vivo Model to Evaluate the Effect of Cyclical Adductory Forces on Maintenance of Arytenoid Abduction After Prosthetic Laryngoplasty Performed With and Without Mechanical Arytenoid Abduction

摘要

Objectives: To (1) develop a model of cyclical adduction force on an abducted left arytenoid cartilage that mimics swallowing or coughing; (2) determine if arytenoid abduction by a clamp before knot tying will improve the maintenance of abduction under cyclical adduction testing. Study Design: Experimental. Sample Population: Cadaveric equine larynges (n = 14). Methods: Left laryngoplasty performed using a single suture of #5 Ethibond with (n = 7) and without (n = 7) abducting the arytenoid with a clamp before knot tying. Each laryngoplasty was loaded cyclically from 2 to 26 N at 0.5 Hz for 5000 cycles in a servohydraulic test frame. Arytenoid displacement data were collected at 1 Hz intervals and median percent loss of abduction compared between groups. Significance was set at P<.05. Results: Median left arytenoid abduction distance was 16.9 m m (range, 9.8-19.8 mm). One larynx in each group failed at <1000 cycles. Loss of abduction was determined by progressive displacement of the testing actuator and confirmed by measurement. There was no difference in loss of abduction between clamped and non-clamped larynges after 5000 cycles. This model of cyclical adduction resulted in arytenoid displacements similar to those seen in the 1st week postoperatively. Conclusions: Ex vivo cyclical adductory forces produced a significant loss of laryngoplasty abduction. The use of a clamp to abduct the arytenoid cartilage before knot tying did not reduce the loss of abduction