Voice Outcomes after Expansion Sphincter Pharyngoplasty in Patients with Obstructive Sleep Apnea Syndrome

The aim of this study was to evaluate the temporal changes in perceptual, acoustic, and cepstral voice parameters following expansion sphincter pharyngoplasty (ESP) in patients with moderate-severe obstructive sleep apnea syndrome (OSAS).

In this prospective, nonrandomized clinical study, ESP was performed on 27 adult patients with moderate-severe OSAS. Voice assessments were conducted preoperatively, at 1 week postoperatively, and at 3 months postoperatively using the Turkish Voice Handicap Index-10, Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) scale, acoustic parameters (fundamental frequency, jitter %, shimmer %, and noise-to-harmonic ratio [NHR]), formant frequencies (F1-F4), and cepstral measurements (cepstral peak prominence [CPP], smoothed cepstral peak prominence [CPPS]) during sustained /a/ phonation and connected speech. Statistical analyses were performed using the Friedman test and Analysis of Variance (ANOVA).

Regarding perceptual evaluation, although Friedman tests indicated statistical variance in Grade (P = 0.016) and Roughness (P = 0.005), conservative post hoc analyses revealed no statistically significant pairwise differences, suggesting perceptual stability. Objective acoustic analysis demonstrated a significant increase in Shimmer (P = 0.020) and a decrease in NHR (P = 0.011) by the third postoperative month. Cepstral analysis revealed a significant decrease in sustained /a/ CPP (P = 0.007) and CPPS (P = 0.010), reflecting reduced signal periodicity, while connected speech CPP showed significant variance (P = 0.020).

ESP characterizes as a functionally safe and resonance-sparing intervention. Although the procedure induces subclinical acoustic perturbations manifesting as reduced signal periodicity, it maintains perceptual stability and does not compromise functional communication. Preoperative counseling regarding these subtle acoustic changes is recommended, particularly for professional voice users.