High-speed digital imaging of the neoglottis after supracricoid laryngectomy with cricohyoidoepiglottopexy

Objective: To determine the utility of high-speed digital imaging (HSDI) in evaluating vocal kinetics of the neoglottis after supracricoid laryngectomy with cricohyoidoepiglottopexy (SCL-CHEP). Study Design: Case series. Setting: The University of Tokyo Hospital. Subjects and Methods: High-speed digital recordings of laryngeal images were obtained from six patients after SCL-CHEP to clarify the vocal kinetics of the postoperative neoglottis. Simultaneous recording of electroglottograms (EGGs) were obtained and multiline kymograms were generated on the basis of the recorded images. The distribution of frequency, amplitude, and phase in the neoglottis were visualized by using gradients of colors superimposed onto the glottal and supraglottal areas of laryngeal images to produce laryngeal topograms. Furthermore, waveforms of estimated laryngeal sound source (ELSS) were obtained on the basis of glottal inverse filtering of the vocal signal to reflect vibratory motions in the neoglottis. The vibratory part of the neoglottis was determined as a possible sound source when the frequencies of the ELSS, EGG, and laryngeal topograms, as well as the waveforms of ELSS, EGG, and kymograms, were consistent with each other. Results: Spaces between the arytenoid(s) and epiglottis (5 patients) or pyriform sinus mucosa (1 patient) were estimated as the major source of sound during postoperative vocalization. The possible sound source could be determined by HSDI, even in the neoglottis, with more than one vibratory position. Conclusion: HSDI could be useful for evaluating the vocal kinetics of the neoglottis after SCL-CHEP.