Objective: Posterior laryngeal stenosis is a known complication of endotracheal tube intubation. The placement of an endotracheal tube (ETT) through the glottis applies pressure on the laryngeal tissues between the arytenoids, which is some patients can lead to stenosis. Patients who are tall tend to be at less risk for the development of stenosis than shorter patients. The purpose of this study is to explore the effect of pharyngeal length on interarytenoid pressures.
Method/Design: We developed a prototype endotracheal tube (ETT) with an applied pressure sensor to measure posterior laryngeal pressures. Using an adjustable laryngeal model with a soft three-D printed larynx we measured interarytenoid pressures at several degrees of anterior laryngeal displacement leading to a more acute Hypopharyngeal-Laryngeal Angle ( HLA) . We then increased the length of the pharynx to determine the effect on the interarytenoid pressures.
Hypothesis: Our hypothesis is that at any given anterior displacement of the larynx an increase in pharyngeal length will result in a decrease in interarytenoid pressure by increasing the Hypopharyngeal -Laryngeal Angle .