A Biomechanical Study of Hyoid Bone and Laryngeal Movements During Swallowing Comparing the Blom Low Profile Voice Inner Cannula and Passy-Muir One Way Tracheotomy Tube Speaking Valves.

The aim of this prospective, consecutive, cohort study was to investigate the biomechanical effects, if any, of the Blom low profile voice inner cannula and Passy-Muir one-way tracheotomy tube speaking valves on movement of the hyoid bone and larynx during swallowing. Ten adult patients (8 male, 2 female) with an age range of 61-89 years (mean 71 years) participated. Criteria for inclusion were ≥18 years of age, English speaking, and ability to tolerate both changing to a Blom tracheotomy tube and placement of a one-way tracheotomy tube speaking valve with a fully deflated tracheotomy tube cuff. Digitized videofluoroscopic swallow studies were performed at 30 frames/s and with each patient seated upright in the lateral plane. A total of 18 swallows (three each with 5 cc bolus volumes of single contrast barium and puree + barium × 3 conditions) were analyzed for each participant. Variables evaluated included larynx-to-hyoid bone excursion (mm), maximum hyoid bone displacement (mm), and aspiration status under three randomized conditions: 1. Tracheotomy tube open with no inner cannula; 2. Tracheotomy tube with Blom valve; and 3. Tracheotomy tube with Passy-Muir valve. Blinded reliability testing with a Pearson product moment correlation was performed on 20 % of the data. Intra- and inter-rater reliability for combined measurements of larynx-to-hyoid bone excursion and maximum hyoid bone displacement was r = 0.98. Intra- and inter-rater reliability for aspiration status was 100 %. No significant differences (p > 0.05) were found for larynx-to-hyoid bone excursion and maximum hyoid bone displacement during swallowing based upon an open tracheotomy tube, Blom valve, or Passy-Muir valve. Aspiration status was identical for all three randomized conditions. The presence of a one-way tracheotomy tube speaking valve did not significantly alter two important components of normal pharyngeal swallow biomechanics, i.e., hyoid bone and laryngeal movements. Aspiration status was similarly unaffected by valve use. Clinicians should be aware that the data do not support placement of a one-way tracheotomy tube speaking valve to reduce prandial aspiration.

Epiglottis is not essential for successful swallowing in humans.

Controversy has continued for well over 100 years regarding the role of the epiglottis in deglutition. We describe the effect of isolated epiglottectomy on swallowing success in a case series of 3 adult human subjects with isolated epiglottectomy due to trauma, surgery, or cancerous erosion. The patients were 42, 51, and 70 years of age, and swallowing was analyzed objectively with videofluoroscopy. All subjects exhibited successful swallowing with all food types: thin liquid, puree, and solid food. Specifically, the patient with traumatic epiglottectomy exhibited rapid swallowing success, the patient with surgical epiglottectomy exhibited a short period of dysphagia due to postoperative edema, followed by swallowing success, and the patient with epiglottectomy due to cancerous erosion of the entire epiglottis exhibited long-term adaptation, with successful swallowing maintained. We conclude that the epiglottis is not essential for successful swallowing in humans, because individuals can readily adapt to isolated epiglottectomy and avoid tracheal aspiration.

Hyoid bone and laryngeal movement dependent upon presence of a tracheotomy tube.

The aim of this prospective, consecutive study was to investigate the biomechanical effects, if any, of the presence of a tracheotomy tube and tube cuff status, tube capping status, and aspiration status on movement of the hyoid bone and larynx during normal swallowing. Seven adult patients (5 male, 2 female) with an age range of 46-82 years (mean = 63 years) participated. Criteria for inclusion were no history of cancer of or surgery to the head and neck (except tracheotomy), normal cognition, normal swallowing, and ability to tolerate decannulation. Digital videofluoroscopic swallowing studies were performed at 30 frames/s and with each patient seated upright in the lateral plane. Variables evaluated included maximum hyoid bone displacement and larynx-to-hyoid bone approximation under three randomized conditions: tracheotomy tube in and open with a 5-cc air-inflated cuff; tracheotomy tube in and capped with deflated cuff; and tracheotomy tube out (decannulated). Differences between maximum hyoid bone displacement and larynx-to-hyoid approximation (cm) based on presence/absence of a tracheotomy tube, tube cuff status, and tube capping status were analyzed with the Student's t test. Reliability testing with a Pearson product moment correlation was performed on 21% of the data. No significant differences (p > 0.05) were found for both maximum hyoid bone displacement and larynx-to-hyoid bone approximation during normal swallowing based on tracheotomy tube presence, tube cuff status, or tube capping status. Intraobserver reliability for combined measurements of maximum hyoid displacement and larynx-to-hyoid approximation was r = 0.97 and interobserver reliability for the absence of aspiration was 100%. For the first time with objective data it was shown that the presence of a tracheotomy tube did not significantly alter two important components of normal pharyngeal swallow biomechanics, i.e., hyoid bone movement and laryngeal excursion. The hypothesis that a tracheotomy tube tethers the larynx thereby preventing hyoid bone and laryngeal movement during normal swallowing is not supported.