Use of High-Resolution Laryngeal Ultrasound in Assessing Vocal Cord Mobility Before and After Thyroid Surgery: A Prospective Observational Study.

Background: Recurrent laryngeal nerve (RLN) injury remains one of the most significant complications of thyroid surgery, potentially resulting in vocal cord paralysis and voice changes. Flexible laryngoscopy is considered the gold standard for vocal cord assessment; however, it is invasive and may be uncomfortable for patients. High-resolution laryngeal ultrasound (HRLUS) has emerged as a non-invasive alternative for evaluating vocal cord mobility.  Aim: To evaluate the effectiveness of high-resolution laryngeal ultrasound in assessing vocal cord mobility before and after thyroid surgery. Methods: A prospective observational study was conducted at Uttar Pradesh University of Medical Sciences (UPUMS), Saifai, from April 2025 to March 2026. Forty-five patients undergoing thyroid surgery were assessed preoperatively and postoperatively using HRLUS. Findings were compared with flexible laryngoscopy. Diagnostic accuracy, vocal cord mobility, and postoperative complications were analyzed. Results: A total of 45 patients undergoing thyroid surgery were enrolled. The mean age was 41.8 ± 11.6 years, and females constituted 33 (73.3%) of the study population. HRLUS successfully visualized the vocal cords in 40 (88.9%) patients, while flexible laryngoscopy successfully assessed all patients. Postoperative vocal cord paresis was detected in four (8.9%) patients. Compared with flexible laryngoscopy, HRLUS demonstrated a sensitivity of 90.0%, specificity of 97.4%, positive predictive value of 81.8%, negative predictive value of 98.7%, and excellent agreement (κ = 0.91, p<0.001).  Conclusion: High-resolution laryngeal ultrasound is a reliable, non-invasive, and accurate modality for assessing vocal cord mobility before and after thyroid surgery. It may serve as an effective screening tool, reducing the need for routine postoperative laryngoscopy.  Recommendation: HRLUS may be considered a first-line screening tool for perioperative vocal cord assessment, with flexible laryngoscopy reserved for inconclusive or abnormal ultrasound findings.