Study Reveals Significant Vocal Changes After Thyroid Surgery, Even Without Nerve Damage

"Increased efforts are necessary to understand the extent and underlying mechanisms of vocal alterations following thyroid surgery, aiming to reduce the morbidity linked to this widely performed procedure," they wrote in The Egyptian Journal of Otolaryngology.

Following thyroid surgery, vocal changes are noted to be a common complication and recognized morbidity associated with both neuronal and non-neuronal disruptions in voice function. However, the effects of these changes on various vocal characteristics remain inadequately understood, and the underlying mechanisms are still poorly defined. To identify the diagnostic indicators related to post-thyroidectomy vocal alterations, Aya Essam Shrkawy, Phoniatric Unit and ENT Department, Faculty of Medicine, Assiut University, Assiut, Egypt, and colleagues aimed to deliver a comprehensive, multidimensional assessment of vocal function following thyroid surgery.

For this purpose, the researchers conducted a one-year prospective cohort study involving 100 adult patients with an average age of 40.19 (± 12.82) years, who were recruited from the outpatient clinic of the Phoniatric Unit at Assiut University Hospital. These patients were scheduled for thyroid surgery between November 2020 and November 2021.

All participants underwent vocal assessments preoperatively and at 15 days, one month, and two months postoperatively. This included a subjective evaluation of voice complaints using the Voice Handicap Index (VHI-30), auditory perceptual assessment (APA), videolaryngoscopy, and acoustic analysis through a computerized speech lab (CSL). Statistical analyses were performed to compare the various voice assessment parameters across the different time points.

The study led to the following findings:

• The voice changes were significantly decreased from 51.0% after 15 days postoperatively to 33.0% after two months of follow-up.
• Among these cases, 35.0% developed vocal fold paralysis and complained of a breathy voice (27% developed unilateral vocal fold paralysis, and 8% developed bilateral focal fold lesions). The remaining 16.0% of cases had no paralytic manifestations.
• Only one case developed gross lesions “bilateral vocal fold nodules.”
• The subjective evaluation of voice outcome after thyroidectomy showed significant improvement in VHI subscales and total score from 15 days postoperatively to 2 months of follow-up.
• There was a significant difference in all acoustic parameters except HNR across the different assessment settings.

"Our findings revealed that post-thyroidectomy, the deterioration of voice quality is a frequently observed issue. Patients and caregivers should be made aware of the specific subjective discomforts that often accompany thyroid surgery. Additionally, clinicians should inform patients that temporary voice difficulties are common after total thyroidectomy, even in the absence of laryngeal nerve damage," the researchers concluded.

Reference:

Aref, E. E., Ahmed, G. A., Ibrahim, R. A., & Shrkawy, A. E. (2024). Vocal dysfunction following thyroid surgery: A multidimensional subjective and objective study. The Egyptian Journal of Otolaryngology, 40(1), 1-9. https://doi.org/10.1186/s43163-024-00663-9