Voice and healing after vocal fold epithelium removal by CO2 laser vs. microlaryngeal stripping.

ABSTRACT

Controversy exists regarding voice recovery after the use of laser vs. microforceps techniques in the removal of benign vocal fold lesions. The purpose of this study is to compare recovery of voice and healing between groups of cats undergoing vocal fold epithelium removal by CO2 laser and those having vocal fold stripping. Fourteen adult female cats underwent standardized unilateral vocal fold injuries by CO2 laser ablation or stripping. After a 6-week recovery period, phonations were evoked by electrical stimulation of the midbrain periaqueductal gray area. Phonations were recorded for acoustic analysis. The larynges were harvested, fixed, and sectioned for histologic correlation. Acoustic analysis showed the mean signal-to-noise ratios in the laser group (19.72) to be significantly higher than those in the stripped group (13.51) (p = 0.04). The stripped group showed significantly greater amplitude perturbation (8.68% vs. 2.43%, p = 0.02). No between-group difference was found for period perturbation. Histologically, the laser group showed minimal Reinke's space scarring and near-normal epithelial regeneration, and the stripped group showed marked subepithelial scarring, often involving the vocalis muscle. These results demonstrate superior recovery of voice and healing in animals undergoing vocal fold epithelium removal with the CO2 laser. Inferior outcomes seen in the stripped group may be related to difficulty in preserving Reinke's space during epithelium removal.