In vitro evaluation of the effect of a prototype dynamic laryngoplasty system on arytenoid abduction.

Objective: To determine the effect of a prototype dynamic laryngoplasty system (DLPS) on arytenoid abduction.

Study Design: In vitro experimental.

Study Population: Ten equine larynges.

Methods: Dissected larynges were mounted, and the right arytenoid was maximally abducted for testing. A left-sided laryngoplasty (LP) was performed by using a strand of No. 2 FiberWire and a FASTakII anchor. Phase 1 involved tightening the suture, without the DLPS device in place, in 1-mm increments and acquiring a digital image of the rima glottidis at each increment. Phase 2 involved tying the suture with the DLPS in place at a left to right quotient (LRQ) of 0.7. Digital images were subsequently taken at 3 stages of DLPS activation (0, 25, and 50 or maximal psi) and analysed to calculate LRQ.

Results: All tests were completed for 9 larynges. In phase 1, a total shortening of 25.89 ± 1.27 mm was possible, which increased the LRQ from 0.59 ± 0.02 to 1.07 ± 0.12. In phase 2, activation of the DLPS increased the LRQ from 0.70 ± 0.05 to 0.97 ± 0.09. This change in LRQ equated to 18.7 mm of shortening on the basis of phase 1 results. The maximum psi of the DLPS achieved was 37.33 ± 5.96.

Conclusion: The DLPS increased the degree of arytenoid abduction in vitro. This change in LRQ equated to 18.7 mm of shortening of the LP suture based on phase 1 results.

Clinical Impact: These results support further evaluation of the DLPS to determine the effect of changes in DLPS on airway resistance.