Evaluation of Voice and Vocal Fold Vibration after Thyroidectomy Using Two-Dimensional Scanning Digital Kymography and High-Speed Videolaryngoscopy

Does neuromonitoring affect voice quality in patients subjected to a complete thyroidectomy ?

Voice dysfunction is the most common complication of thyroid surgery. The use of intraoperative neuromonitoring (IONM) is to protect the recurrent laryngeal nerves, the damage of which causes voice dysfunction. The aim of the study was to evaluate voice quality in patients who underwent complete thyroidectomy operated on with the application of IONM as well as a group of patients operated on with only macroscopic nerve visualization. In the analysis, clinical voice assessment was performed with particular focus on voice efficiency using the Voice Handicap Index (VHI), Vocal Tract Discomfort (VTD) and GRBAS scale. The study group consisted of 205 patients operated on with IONM. The control group consisted of 162 patients subjected to surgery only with macroscopic visualization of recurrent laryngeal nerves, without IONM. During the follow-up period from 2 to 10 years after surgery, checkups were performed. Each patient who came for a checkup was subjected to perceptual voice evaluation with the use of the GRBAS scale, indirect laryngoscopy procedure and voice selfevaluation with two questionnaires (VHI and VTD). The frequency of vocal fold palsy did not differ significantly statistically in the study group and the control group. Both in the study group and in the control group, patients with vocal fold paralysis had statistically significantly higher results in the VHI and VTD questionnaires as well as in the GRBAS study. Patients with recurrent laryngeal nerve injury show significant differences in the scope of voice handicap, both in the voice quality assessment with the use of the GRBAS scale, and self-evaluation questionnaires: VHI and VTD. All voice disorders evaluated with self-assessment are medium voice disability.