A transthyroidal method for arytenoid adduction: a basic anatomical study

Arytenoid adduction is a very effective procedure for medializing the posterior part of the vocal fold in vocal fold paralysis. Major drawback of the method is the technically sometimes-difficult access to the arytenoid with increased postoperative morbidity. Aim of this study was to provide basic anatomical data regarding the accessibility of the arytenoid cartilage through a thyroplasty window. Furthermore, to investigate the feasibility of an arytenoid adduction by fixation of a surgical screw to the arytenoid cartilage by using this approach.

10 cadaver larynges, six female and four male, were dissected and measured for our points of interest. A standard manufacture-made surgical screw attached to a suture was anchored to the fovea oblonga of the arytenoid cartilage.

Our anatomical measurements proved a mean distance from the posterior edge of the thyroid window to the arytenoid of about 8-9 mm in male larynges and 7-8 mm in female larynges. The distances did not differ significantly between the sexes. Pulling the anchored surgical screw medializes the posterior part of the vocal fold.

Our data showed that there is a very constant morphometric relation between the thyroplasty window and the arytenoid cartilage. It is known that gender-related differences result in a veritable laryngeal dimorphism in nearly all absolute laryngeal dimensions. These differences appear to a much lesser extend in the distances from the surface to the depth, as was confirmed in our series. Using these findings led us to identification of the fovea oblonga near the muscular process as the most favorable point for fixation of a surgical screw through a conventional thyroplasty window. Pulling the attached suture medializes the arytenoid cartilage.