A Quantitative Examination of Vocal Fold Vibratory Changes Using Two-Dimensional Scanning Digital Kymography After Angiolytic Laser Stripping for Vocal Fold Leukoplakia

Background and Objectives Vocal fold leukoplakia is characterized as white plaque on the epithelium of the vocal folds and can be treated by angiolytic laser stripping surgery. However, postoperative changes in the vibratory patterns of vocal folds have not been investigated quantitatively. The purpose of this study was to investigate the changes in vocal fold vibration after angiolytic laser surgery in patients with unilateral vocal fold leukoplakia using the twodimensional scanning digital kymography (2D DKG).Subjects and Method Medical records of seven males (age=62.14±12.40 yrs) with unilateral vocal fold leukoplakia who underwent angiolytic laser stripping were reviewed. Before and after the surgery (post-operative day=82.57±28.55 days), a multi-dimensional voice assessment was performed along with a 2D DKG study. For 2D DKG images, the amplitude symmetry index (ASI), phase symmetry index (PSI), and open quotient (OQ) were calculated using the ImageJ program. In addition, pre- versus postoperative data were compared, and the correlation between the changes in 2D DKG parameters and voice outcomes was explored.Results Results indicated that the absolute ASI (p=0.028) and OQ (p=0.028) of the 2D DKG study, grade (p=0.038) and breathy (p=0.034) of the GRBAS scale, σPitch measured by the electroglottography (p=0.043), the physical score of the VHI (p=0.042), and the total score (p=0.043) and the tiredness score (p=0.043) of the VFI decreased after surgery. Decrease in the absolute ASI was correlated with changes in the grade (rho=0.850) and breathy (rho=0.777) scale measures, while decreased OQ were correlated with the changes in the physical score of the VHI (rho=0.901) and tiredness score of the VFI (rho=0.847).Conclusion The improved vocal fold vibratory patterns after angiolytic laser surgery for vocal fold leukoplakia can be evaluated objectively using the 2D DKG study. Angiolytic laser stripping enables the preservation of vocal fold vibration after the surgery and is considered a valuable surgical option for treating vocal fold leukoplakia.