Korean J Otorhinolaryngol-Head Neck Surg.  2023 Nov;66(11):750-757. 10.3342/kjorl-hns.2023.00941.

Prediction of Voice Outcomes After Hemithyroidectomy Using Skin Electrode Intraoperative Neuromonitoring

• Lee D
• Kim HG
• Kwon M
• Cho JG
• Oh KH
• Baek SK
• Kwon SY
• Woo JS
• Jung KY

• KMID: 2548019
• DOI: http://doi.org/10.3342/kjorl-hns.2023.00941

Abstract

Background and Objectives
This study focused on predicting voice outcomes following hemithyroidectomy using skin electrode intraoperative neuromonitoring (IONM).
Subjects and Method
The study involved 82 patients who underwent hemithyroidectomy. During the surgery, the researchers recorded skin IONM values for the vagus nerve and recurrent laryngeal nerve. Voice quality evaluations were conducted before the surgery and at various intervals after the surgery (one week, one month, three months, six months, and one year) using the multidimensional voice program (MDVP), voice handicap index (VHI), and the grade, roughness, breathiness, asthenia, strain (GRBAS) scale. The study aimed to correlate perioperative skin IONM values with subjective and objective voice outcomes.
Results
The VHI scores increased up to three months post-surgery, with statistically significant changes observed at one week post-surgery. The GRBAS scale scores also increased significantly at one month post-surgery. Similar trends were observed in the MDVP data, including a decrease in the maximum pitch between one week and three months post-surgery. Additionally, the study found that lower delta-V values (difference between the preoperative and postoperative signal amplitude of vagus nerve stimulation) were associated with higher F0 values at one week and three months post-surgery, while jitter and noise-to-harmonic ratio were higher in the group with higher delta-V values at three months post-surgery.
Conclusion
Greater differences between the preoperative and postoperative signal amplitude of vagus nerve stimulation during surgery were linked to worse postoperative voice outcomes. Voice parameters worsened for up to 3 months after hemithyroidectomy but showed signs of recovery afterwards. These findings offer insights into predicting and managing voice outcomes after hemithyroidectomy.

Keyword

Electrodes; Recurrent laryngeal nerve, Thyroidectomy; Vagus nerve; Voice disorders