Vocal fold medialization using autologous cartilage in a canine model: a preliminary study

Unilateral vocal fold paralysis can alter phonation. Medialization of the vocal fold using cartilage augmentation dates to the early 1950s. Improved phonation after cartilage chordal augmentation has been reported, but no study has as yet documented cartilage viability or size in this setting over time. The authors of this study evaluated thyroid alar cartilage as a medializing material in three mongrel dogs. Grafts were inserted lateral to the inner thyroid perichondrium at the vocal fold level via a window in the thyroid cartilage. Changes in weight, size, and volume were assessed 6 months after implantation. The average graft weight declined by 15%, and the average square area declined by 3%. Importantly, the average volume maintained was 87%. The grafts remained rigidly fixed to the thyroid cartilage in their placement positions. Histologic examination documented minimal resorption. The data suggest that thyroid alar cartilage is a viable filler in type I thyroplasty procedures.