Sectional anatomy of the larynx: implications for the transcutaneous approach to endolaryngeal structures.

A transcutaneous, transcricothyroid membrane approach to endolaryngeal structures is used for several techniques such as placement of electrodes for laryngeal electromyography and transcutaneous Teflon injection of the paralyzed vocal fold. The purpose of this study is to examine the sectional anatomy of the larynx with respect to the cricothyroid membrane and describe a suitable transcutaneous approach to endolaryngeal structures. Sixteen whole organ cadaveric larynges were frozen in clear gelatin to facilitate sectioning. Specimens were sectioned in the transaxial, sagittal, and coronal planes as well as 30 degrees, 45 degrees, and 60 degrees from the transaxial plane. For clinical orientation, the transaxial plane was defined as 90 degrees from the most anterior plane of the cricothyroid membrane. Sections were examined and angles and depths of penetration were measured with respect to the transcutaneous approach to endolaryngeal structures.