Subjective and Objective Voice Assessments After Recurrent Laryngeal Nerve-Preserved Total Thyroidectomy

This study aims to investigate early voice changes after total thyroidectomy, to assess the improved parameters in intermediate postoperative intervals, to evaluate the effect of age on voice after thyroidectomy, and to determine the correlation between the objective and the subjective method outcomes.

This is a prospective, nonrandomized study.

One hundred ninety-one participants, divided into two age groups, underwent three full voice assessments (preoperatively and 1 and 8 weeks after thyroidectomy) by means of videostroboscopy, perceptual evaluation, acoustic analysis, aerodynamic evaluation, and a self-evaluation questionnaire. Two control groups enrolled in the study: (1) patients with an indication of neck surgery not related to laryngeal nerve injury risk or strap muscle dissection and (2) patients with an indication of a non-neck surgery.

No statistically significant difference was found in any voice parameter, between preoperative and 1-week postoperative assessment regarding the control groups. A statistically significant difference was found between preoperative evaluation and 1 week after thyroidectomy for the total study population, as well as for the ≥40 years' age subgroup for all parameters evaluated except for shimmer. The <40 years' age subgroup showed a statistically significant difference in pitch, maximum phonation time, and grade, roughness, breathiness, asthenia, and strain (GRBAS) score between preoperative evaluation and 1 week after thyroidectomy. None of the parameters showed a statistical significant difference in the <40 years' age subgroup at 8 weeks' evaluation. The Voice Handicap Index (VHI) score correlated significantly with the GRBAS score preoperatively and postoperatively at 1 and 8 weeks' evaluations. Furthermore, VHI correlated significantly with pitch a week postoperatively. GRBAS scores showed significant correlation not only with VHI but also with acoustic parameters including pitch, shimmer, and noise-to-harmonic ratio 1 and 8 weeks after thyroidectomy.

Objective voice changes are common in the majority of the thyroidectomized patients in the early postoperative period. Our results revealed that these changes are related to thyroidectomy per se. Older patients (≥40 years of age) show acoustic and aerodynamic changes 8 weeks postoperatively, although they report no voice abnormalities and their perceptual evaluation is similar to the preoperative one.