Study of Arytenoid Adduction Under Laryngotracheal Intubation in Excised Human Larynges

The objective of this study was to assess the degree of medialization of the arytenoid vocal process obtained with the technique of adduction of the arytenoid cartilage under laryngotracheal intubation with tubes of different sizes.

This was an experimental study carried out with 16 human larynges excised from adult cadavers, nine male and seven female. Glottic closure was produced with adduction of the arytenoid cartilage, using the technique adapted from Isshiki. The medial projection of the arytenoid vocal process was assessed after using orotracheal tubes of sizes 5.0, 6.0, and 7.0 mm (with an external diameter of 6.9, 8.2, and 9.6 mm). The recordings were made on a digital camera and the measurements were checked using the "ImageJ" program.

In the procedures carried out with the 5.0 mm tube, the adduction obtained in relation to the midline (ML) was the same as that obtained in the absence of the tube (P < 0.05), with a gap of 0.194 mm [-0.169 to 0.448], but with hyperadduction in 31.2% of the cases. Adduction in the presence of the 6.0 and 7.0 mm tubes was less effective (P > 0.05), with a gap in relation to the ML of 0.403 mm [0.239; 0.641] and 0.639 mm [0.344; 0.756], respectively.

This study showed that it is possible to perform arytenoid adduction to medialize the vocal process of the arytenoid cartilage in the presence of orotracheal tubes of sizes 5.0, 6.0, and 7.0 mm. Although in the presence of the 5.0 mm tube it was possible to medialize the vocal process similar to the absence of the tube (P < 0.05), there was a risk of hyperadduction. In the presence of the 6.0 mm tube, there was an acceptable gap and low risk of hyperadduction of the vocal process.