Abstract:
Objective
To assess the dynamic functional changes of the recurrent laryngeal nerve （RLN） following thyroid microwave ablation （MWA） through quantitative transcutaneous laryngeal ultrasonography （TLUSG） by integrating real-time vocal fold kinematic visualization and parametric analysis.
Methods
This retrospective cohort study analyzed 63 consecutive patients who underwent unilateral thyroid nodule MWA at a tertiary academic center between January 2022 and May 2024. TLUSG was performed preoperatively， immediately post-ablation， and at 1/3/6-month follow-ups. Dynamic vocal fold motion was recorded during phonation （‘e’ sustained） and quiet breathing， with optimal frozen images analyzed for angular measurements （anterior commissure displacement） and maximum glottic width. A linear mixed-effects model with repeated measures ANOVA was used to evaluate temporal trends， group effects （ablated vs contralateral side）， and interaction terms， and the Bonferroni method was used for pairwise comparisons.
Results
Significant time main effects were observed for vocal fold angle （Ftime=14.885，P＜0.001） and maximum displacement （Ftime=10.599， P=0.001） on the treated side. Neither group main effects nor group-time interactions reached statistical significance （P＞0.05 for all）. Post hoc analysis demonstrated immediate postoperative reductions in treated-side maximum displacement and angle ［（7.652±0.226） mm vs （7.887±0.364） mm， t=-4.212， P＜0.001； （24.984±0.258）° vs （26.222±0.303）°， t=-5.982， P＜0.001），with values returning to baseline levels by postoperative month 1 （P＞0.05 at 1/3/6 months）. No significant temporal variations were detected in contralateral vocal fold parameters （P＞0.05 across all intervals）.
Conclusion
TLUSG can non-invasively， rapidly， economically， accurately， and quantitatively assess the vocal cord movement of patients undergoing thyroid microwave ablation in real time during surgery and in outpatient settings， reducing the need for invasive flexible laryngoscopy， and plays an important auxiliary role in the dynamic monitoring of recurrent laryngeal nerve function.
Key words:
Transcutaneous laryngeal ultrasonography,
Flexible laryngoscopy,
Vocal cords,
Recurrent laryngeal nerve
Jingjing Xu, Nian'an He, Xianjun Ye, Xiaoyu Qi, Yanmei Zhang. Assessment of recurrent laryngeal nerve function changes using transcutaneous laryngeal ultrasound in patients after thyroid microwave ablation[J]. Chinese Journal of Medical Ultrasound (Electronic Edition), 2025, 22(03): 224-229.