There are few data demonstrating the specific extent to which surgical intervention for vocal fold nodules (VFN) improves vocal function in professional (PVU) and non-professional voice users (NVU). The objective of this study was to compare and quantify results after phonomicrosurgery for VFN in these patient groups.
Methods: In a prospective clinical study, surgery was performed via microlaryngoscopy in 37 female patients with chronic VFN manifestations (38±12 yrs, mean±SD). Pre- and postoperative evaluations of treatment efficacy comprised videolaryngostroboscopy, auditory-perceptual voice assessment, voice range profile (VRP), acoustic-aerodynamic analysis, and voice handicap index (VHI-9i). The dysphonia severity index (DSI) was compared with the vocal extent measure (VEM).
Results: PVU (n=24) and NVU (n=13) showed comparable laryngeal findings and levels of suffering (VHI-9i 16±7 vs 17±8), but PVU had a better pretherapeutic vocal range (26.8±7.4 vs 17.7±5.1 semitones, p<0.001) and vocal capacity (VEM 106±18 vs 74±29, p<0.01). Three months postoperatively, all patients had straight vocal fold edges, complete glottal closure, and recovered mucosal wave propagation. The mean VHI-9i score decreased by 8±6 points. DSI increased from 4.0±2.4 to 5.5±2.4, and VEM from 95±27 to 108±23 (p<0.001). Both parameters correlated significantly (rs=0.82). The average vocal range increased by 4.1±5.3 semitones, and the mean speaking pitch lowered by 0.5±1.4 semitones.
Conclusions: These results confirm that phonomicrosurgery for VFN is a safe therapy for voice improvement in both PVU and NVU who do not respond to voice therapy alone. Top-level artistic capabilities in PVU were restored, but numeric changes of most vocal parameters were considerably larger in NVU.