Excised larynx evaluation of wedge-shaped adjustable balloon implant for minimally invasive type I thyroplasty.

Abstract

To describe the method of inserting a wedge-shaped adjustable balloon implant (wABI) via a minithyrotomy for medialization thyroplasty and evaluate its effect on a range of phonatory parameters using the excised larynx bench apparatus. Repeated measures with each larynx serving as its own control. A prototype wABI was deployed in six excised canine larynges of various sizes through a minithyrotomy and then filled with saline. Mucosal wave, aerodynamic, and acoustic parameters were measured for three conditions: normal, vocal fold paralysis, and paralysis with the wABI. Phonation threshold pressure (P < .001), flow (P < .001), and power (P = .002) were significantly lower for wABI compared to paralysis trials; values did not differ significantly from normal trials. Percent jitter (P = .002) and percent shimmer (P = .007) were also significantly decreased compared to the paralysis condition, and values were not significantly different compared to normal. The mucosal wave was preserved after insertion of the wABI. Effective vocal fold medialization with preservation of the mucosal wave was observed with the wABI in this preliminary excised larynx experiment. The wABI offers the potential for a minimally invasive insertion in addition to postoperative adjustability. Further studies in living animals and humans are warranted to evaluate clinical utility. NA.