Voice function in patients after extended fronto-lateral laryngectomy.

The main purpose of this study was subjective and objective evaluation of voice function before and after extended frontolateral laryngectomy, followed by reconstruction with a mucochondrial graft from the nose. The next aim of this study was analysis of phoniatric and acoustic results depending on: (1) the extent and localization of the neoplastic process; (2) the wound-healing process (including the time of decannulation and effective deglutition); (3) the substitute mechanism of phonation. In all, 40 patients (37 men and 3 women) having T1B (67.5%) and T2 (32.5%) glottic cancers were examined before and after the operation. The ENT investigation included each patient's history from the beginning of illness, a subjective evaluation of the voice by patients before and after the operation, determination of laryngeal mobility of the larynx and indirect laryngoscopy during phonation. Phoniatric examination included voice recordings, average voice pitch, voice range, maximum phonation time, microlaryngoscopy and microstroboscopy. Acoustic analysis covered the harmonic structure of the voice, jitter, shimmer, noise components and basic frequency. Results showed that the extent of the neoplastic process before operation did not affect essential voice quality after operation in stage T1B and T2 disease. The maximum phonation time was shortened in T1B patients from 16.5 s to 9.28 s and in T2 from 16.7 s to 9.8 s. The average voice pitch was decreased in T1B from 177.3 Hz to 111.74 Hz and in T2 from 163.8 to 99 Hz. A correlation between acoustic analysis and phoniatric examinations was found. The value of the first formant decreased by 15.1 Hz, jitter increased 2%, shimmer increased 0.9 dB and basic frequency decreased. The voice quality after operation showed a statistically significant dependence on the mechanism of phonation. The best results were found in patients in whom phonation was the result of removing the vocal fold and postoperative scar vibration. The worst results were found in those patients with a sphincter mechanism of phonation.