[Videofluoroscopic evaluation of the functional significance of the epiglottis in adults].

Our intention was to define the functional role of the epiglottis. Accordingly, we analysed its movements and correlation in 53 videofluroscopic exams: 26 were good health volunteers, 25 were patients with dysphagia and two were persons with pharyngeal diverticula. The exams register the rest phase, chewing, and the swallowing movements during the intake of the saliva, water, barium solution and different volumes of mass made with crumbled bread mixed with barium powder. We can see three sequential stages in epiglottic movement during swallowing. The first stage involves an upward epiglottic shift determined by hioepiglottic ligament, associated with a simultaneous bending caused by the tongue backward projection. The second stage is a posterior rotation of the epiglottis, limited by the adjustment of the epiglottic tubercle to the vestibular fold, determined by laryngeal upward shift against hyoid bone. The third stage in which occurs an eversion of the free extremity of the epiglottis beyond the horizontal plane can be absent in slow pressure swallowing. All stages of the epiglottic dynamics are passive. We have shown that the epiglottis has a protective action on the repiratory airways not limited to swallowing. It participates, during swallowing and regurgitation (vomica), through the passive adjustment of the intralaryngeal posterior surface of the epiglottis (epiglottic tubercle) to the vestibular folds. Both before and after swallowing, when frequently there are escapes of residues and small volumes out of the oral cavity, the epiglottis protects the repiratory airways, through its participation in the formation of the valleculae and as an insertion point for the aryepiglottic folds. In association with epiglottis participation there is a stretching of the aryepiglottic folds that allow a definition of the lateral channels. The upward and forward movements of the larynx associated with the opening of the pharyngoesophageal transition, that occurs synchronously with the ejection of the swallowed bolus, has been shown to be an important factor in the protective laringeal mechanism. The increase in the laryngeal resistance, in which the epiglottis takes part, is only efficient when there is wide and synchronous opening of the pharyngoesophageal transition. In this context the epiglottis is a secondary element in the protection of the respiratory airways.