Laryngeal Compensation for Voice Production After CO2 Laser Cordectomy

Carbon dioxide (CO2) laser cordectomy is considered one of the modalities of choice for treatment of early glottic carcinoma. In addition to its comparable oncological results with radiotherapy and open surgical procedures, it preserves of laryngeal functions including voice production. The aim of this study was to detect how the larynx compensates for voice production after different types of CO2 laser cordectomy for early glottic carcinoma together with assessment of the vocal outcome in each compensation mechanism.

One hundred twelve patients treated with CO2 laser cordectomy were classified according to their main postoperative phonatory site. Perceptual analysis of voice samples using GRBAS (grade, roughness, breathiness, asthenia, and strain) scale was done for 88 patients after exclusion of the voice samples of all female patients to make the study population homogenous and the samples of 18 male patients due to bad quality (4 patients) or unavailability (14 patients) of their voice samples and the results were compared with those obtained from control group that included 25 age-matched euphonic male subjects.

Five types of laryngeal compensation were defined including: vocal fold to vocal fold, vocal fold to vocal neofold, vocal fold to vestibular fold, vestibular fold, to vestibular fold, and arytenoids hyper adduction. Characters changes of voice produced by each compensation type were found to be statistically significant except for breathiness, asthenia and strain changes in vocal fold to vocal fold compensation type.

The larynx can compensate for voice production after CO2 laser cordectomy by five different compensation mechanisms with none of them producing voice quality comparable with that of controls.