Evaluation of the Distance Between Anterior Commissure of True Vocal Folds and the First Tracheal Ring and Related Laryngeal Indices in 40 Human Cadavers

Objective. Distorted anatomy in laryngotracheal pathologies expresses the need to determine a quantitative mean of the distance between the anterior commissure of true vocal folds and the first tracheal ring to better define whether a lesion is in the subglottis or has extended toward the trachea. Study Design. This is a descriptive cross-sectional study. Methods. In 40 cadavers, the larynx was exposed with an apron cut. The laryngofissure cut opened the larynx via the lateral aspect so that the anterior commissure was exposed. A needle was passed through the thyroid cartilage to reach the anterior commissure. The second needle was crossed over the first tracheal ring. The distance between the two needles was measured. Results. The mean distance between the anterior commissure of true vocal folds and the first tracheal ring was 26.82 +/- 4.28 mm (21.3-42.5 mm) in our subjects. This distance was 27.27 +/- 4.45 and 25.05 +/- 3.2 mm, in men and women, respectively. There was no statistically significant correlation between this distance with body mass index (BMI), age, and sex. Conclusions. The distance between the anterior commissure and the first tracheal ring in patients with laryngotracheal pathologies helps in determining the best therapeutic plan for patients.