Comparative Analysis of Preoperative and Postoperative Voice Parameters in 93 Cases of Vocal Fold Cyst.
Objective: We investigated the characteristics of vocal fold cysts (VFCs) by assessing preoperative impairments and postoperative improvements across multiple voice parameters.
Methods: Data from 93 VFCs treated with microflap surgery at Kurume University Hospital (1996-2022) were retrospectively reviewed. Cyst size was calculated as the ratio of the cyst diameter to the distance from the anterior commissure to the vocal process. VFCs were histologically classified into retention, epidermoid, and unclassified (due to insufficient tissue) types. They were also classified as subepithelial cysts (VFC-SE) and ligamentous cysts (VFC-lig) based on depth. Postoperative differences (Δ) were calculated for voice parameters, including the maximum phonation time, mean flow rate, fundamental frequency (F0), F0 range in semitones, sound pressure level (SPL), SPL range, pitch perturbation quotient, amplitude perturbation quotient (APQ), jitter, shimmer, normalized noise energy, noise-to-harmonic ratio, and Voice Handicap Index-10 scores.
Results: Patients with epidermoid cysts were significantly younger than those with retention cysts (P = 0.01). All parameters except the SPL range (in men) significantly improved postoperatively, whereas F0 changes were statistically insignificant. Cyst size positively correlated with preoperative APQ (Spearman's ρ = 0.343, P = 0.02) and shimmer (ρ = 0.334, P = 0.03) and negatively correlated with ΔAPQ (ρ = -0.301, P = 0.04) and Δshimmer (ρ = -0.303, P = 0.04). Compared with VFC-lig, VFC-SE showed greater preoperative shimmer (P = 0.01) and a lesser postoperative F0 range (P = 0.0495). The preoperative values and postoperative differences were not significantly different among the histological cyst types.
Conclusions: The age difference between patients with epidermoid and retention cysts may reflect distinct cyst etiologies. Large cysts significantly disrupted preoperative mucosal wave dynamics, particularly affecting amplitude irregularities, with greater potential for postoperative improvement. Microflap surgery effectively improved voice parameters in patients with VFCs, regardless of classification by histology or depth.