Contribution of Undesired Medial Surface Shape to Suboptimal Voice Outcome After Medialization Laryngoplasty

Objectives: Voice production in pathological conditions or after surgical intervention often involves undesired medial surface shape such as reduced vertical thickness and/or left-right asymmetry in medial surface shape. The effect of such undesired medial surface on voice production remains unclear, and is often not taken into consideration during planning of surgical intervention, due to difficulty of imaging the medial surface in patients. This study aims to better understand how voice outcomes are impacted by undesired medial surface shape.

Methods: Computational simulations were conducted to parametrically manipulate medial surface shape and stiffness and observe its consequence on voice production.

Results: The results showed that undesired medial surface shape can result in incomplete glottal closure, weak voice production, increased phonation threshold, and significantly reduced vocal efficiency, particularly in the presence of left-right stiffness asymmetry.

Conclusions: In addition to approximating the vocal folds, medialization laryngoplasty should additionally aim to sufficiently increase medial surface thickness, which may improve voice outcomes in patients whose voices remain unsatisfactory or suboptimal after initial intervention. While a divergent implant may increase medial surface thickness, precise implant placement in anticipation of tissue and implant deformation during the insertion process is equally important in order to achieve desired medial surface shape and optimal voice outcomes.