Impact of unilateral carbon dioxide laser posterior transverse cordotomy on vocal and aerodynamic parameters in bilateral vocal fold paralysis

Abstract

OBJECTIVES: Carbon dioxide laser posterior transverse cordotomy is a common option for bilateral vocal fold paralysis. This study prospectively evaluated aerodynamic and acoustic effects of unilateral carbon dioxide laser posterior transverse cordotomy in bilateral vocal fold paralysis patients. METHODS: The study comprised 11 bilateral vocal fold paralysis patients (9 females, 2 males), with a mean age of 46.6 ± 14.1 years. All patients were treated by laser posterior transverse cordotomy. Pre-operative and two-month post-operative assessments were conducted, including: dyspnoea scales, maximum phonation time measurement, spirometry and bicycle ergometry. RESULTS: All subjective and objective aerodynamic parameters showed statistically significant improvements between the pre- and post-operative period. Objective spirometric and ergometric parameters showed a significant increase post-operatively. The changes in objective voice parameters (fundamental frequency (f0), jitter, shimmer, soft phonation index and noise-to-harmonic ratio) were statistically non-significant; however, there was a significant improvement in subjective voice parameters post-operatively, as assessed by the voice handicap index and grade-roughness-breathiness-asthenia-strain scale (p = 0.026 and p = 0.018 respectively). CONCLUSION: Unilateral carbon dioxide laser posterior transverse cordotomy is an effective procedure that results in improved dyspnoea and aerodynamic performance with some worsening of voice parameters.