Perioperative transcutaneous laryngeal ultrasonography to assess vocal cord function in thyroid surgery

Predictive factors for lymph node metastasis in papillary thyroid cancer patients undergoing neck dissection: insights from a large cohort study

Background

This study aimed to investigate the risk factors and metastatic patterns in papillary thyroid cancer (PTC) patients undergoing lymph node dissection, offering guidance for clinical practice.

Methods

A total of 924 PTC patients who underwent thyroidectomy with central neck dissection (CND) or lateral neck dissection (LND) between January 2021 and November 2022 were included in the analysis. The study investigated the relationships between clinicopathological characteristics, lymph node metastasis, and various risk factor.

Results

Among the 924 PTC patients, the cervical lymph node metastasis rate was 59.1% (546 patients). Of these patients, 381 had central neck metastasis (CNM, 41.2%), while the remaining 165 patients had lateral neck metastasis (LNM, 17.9%). Factors associated with increased risk of CNM and LNM included larger tumor diameter, presence of multiple tumors, and capsular invasion (p<0.05). Male sex, age <55 years, larger tumor diameter (>0.85 cm), multiple tumors, capsular invasion, and absence of Hashimoto's disease were identified as independent risk factors for CNM (p<0.05), with an AUC value of 0.722. CNM, maximum diameter >1.15 cm, and multiple tumors were independent risk factors for LNM (p<0.05), with an AUC of 0.699.

Conclusion

These findings suggest that tailored neck dissection based on individual risk factors is crucial, particularly in cases of suspected LNM with larger tumors, CNM, multiple tumors, and capsular invasion.

Comment on Chatwin et al. Waves of Precision: A Practical Guide for Reviewing New Tools to Evaluate Mechanical In-Exsufflation Efficacy in Neuromuscular Disorders. J. Clin. Med. 2024, 13, 2643

We read with interest the paper published by Chatwin et al [...].

Quantitative Assessment of True Vocal Fold Movement by the Lateral-Approach Laryngeal Ultrasonography: A Pilot Study

BACKGROUND/OBJECTIVES

Ultrasonography is a new method for subjective and qualitative assessment of true vocal fold movement, and true vocal fold visualization with the lateral approach could be better than that with the anterior approach. Our aim was to explore the feasibility of lateral-approach ultrasonography in objective and quantitative assessment of true vocal fold movement.

METHODS

The lateral-approach laryngeal ultrasonography was performed during calm breathing and breath-holding on young healthy adult volunteers in Shanghai, China. The morphology and anatomical position of false vocal fold, true vocal fold, and arytenoid cartilage were observed and measured through the ultrasonic self-contained measurement function. All parameters, including the distance from false vocal fold to thyroid cartilage lamina, true vocal fold length, and the distance from true vocal fold to thyroid cartilage lamina, were obtained at the end of the calm inspiratory and breath-holding phases. Data were analyzed using a t test (P < 0.05).

RESULTS

Forty healthy adult volunteers (age 20 to 34 years, body mass index 19.5 to 23.8 kg/m2, 20 males and 20 females) with satisfactory ultrasonic images were included in the study. There were no significant differences in all laryngeal parameters between the left and right sides in either phase (P > 0.05). From the end of the calm inspiratory phase to the breath-holding phase, changes in all laryngeal parameters were significantly different (P < 0.05), regardless of gender.

CONCLUSIONS

This study demonstrated that the lateral-approach laryngeal ultrasonography seemed feasible to quantify and objectively assess true vocal fold movement, utilizing differences between laryngeal parameters before and after true vocal fold movement.

Surgeon-performed transcutaneous laryngeal ultrasound for vocal cord assessment after total thyroidectomy: a prospective study : Original article

PURPOSE

Assessing vocal cord mobility is crucial for patients undergoing thyroid surgery. We aimed to evaluate the feasibility and efficacy of surgeon-performed transcutaneous laryngeal ultrasound (TLUS) compared to flexible nasolaryngoscopy.

METHOD

From February 2022 to December 2022, we conducted a prospective observational study on patients scheduled for total thyroidectomy at our Institution. All patients underwent TLUS followed by flexible nasolaryngoscopy by a blinded otolaryngologist. Findings were classified as normal or vocal cord movement impairment and then compared. Patients evaluable on TLUS were included in Group A, while those not evaluable were included in Group B, and their features were compared.

RESULTS

Group A included 180 patients, while Group B included 21 patients. Male sex (p < 0.001), age (p = 0.034), BMI (p < 0.001), thyroid volume (p = 0.038), and neck circumference (p < 0.001) were associated with Group B. TLUS showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 99.4%, 94.4%, 100%, and 99.4%, respectively. Cohen's K value was 0.984.

CONCLUSION

TLUS is a valid, easy-to-perform, non-invasive, and painless alternative for evaluating vocal cords in selected patients. It can be used either as a first level exam and as screening tool for selecting cases for flexible nasolaryngoscopy. TLUS should be integrated into routine thyroid ultrasound examination.

Pathophysiological Mechanisms Underlying Unilateral Vocal Fold Paralysis in Female Patients: An Ultrasonographic Study

OBJECTIVES

Laryngeal ultrasonography (LUS) has been suggested as an alternative diagnostic tool for unilateral vocal fold paralysis (UVFP). The present study applied LUS and quantitative laryngeal electromyography (LEMG) in female UVFP patients to investigate the pathophysiologic mechanisms of UVFP.

METHODS

In this cross-sectional study, vocal fold (VF) length parameters included resting and phonating VF length measured using B-mode LUS, and color Doppler vibrating length (CDVL) measured using the color Doppler mode.

RESULTS

Forty female patients with UVFP were enrolled, among whom 11 and 29 were assigned to the thyroarytenoid (TA) muscle+cricothyroid (CT) muscle group (with CT involvement) and the TA (without CT involvement) group, respectively. In the TA group, the turn frequency in thyroarytenoid-lateral cricoarytenoid (TA-LCA) on the paralyzed side, as observed through LEMG, correlated with the VF length during the resting phase (R=0.368, P=0.050) and CDVL values (R=0.627, P=0.000) on the paralyzed side. In the TA+CT group, the turn ratio in the CT muscle correlated with the normalized phonatory vocal length change (nPLC; R=0.621, P=0.041) on the paralyzed side.

CONCLUSION

CDVL and nPLC are two parameters that can be utilized to predict the turn frequencies of TA-LCA in UVFP cases without CT involvement, and the turn ratio of CT in cases of UVFP with CT involvement, respectively. The findings suggest that LUS, as a noninvasive tool, can serve as an alternative method for assessing the severity of laryngeal nerve injury and offer valuable insights into the pathophysiology of UVFP.

Can Transcutaneous Laryngeal Ultrasonography Systematically Quantify Vocal Fold Movement?-A Feasibility Study

OBJECTIVES

Several studies have assessed adult vocal fold movement using transcutaneous laryngeal ultrasonography (TLUSG) during the perioperative period of thyroidectomy. However, the movement was not objectively quantified. This study aimed to provide a feasible and objective method for assessing vocal fold movement using TLUSG.

STUDY DESIGN

Feasibility study.

METHODS

TLUSG was performed during calm breathing and breath-holding in healthy adult volunteers. The morphology and anatomy of the larynx were observed and measured using an ultrasonic self-contained measurement function. At the end of the calm inspiratory and breath-holding phases, vocal fold angle, vocal fold length, distance from vocal process to the midline, distance from anterior vocal commissure to arytenoid cartilage, distance from false vocal fold to the midline, and distance from the anterior horn of thyroid cartilage to false vocal fold were measured. Data were analyzed using a t test (significance <0.05).

RESULTS

The ultrasonic images were satisfactory in all 40 healthy adult volunteers (age 19-35 years; body mass index 18.55-23.93 kg/m2; 20 men and 20 women). There were no significant differences in all laryngeal parameters between the left and right sides in both phases (P > 0.05). Moreover, all differences in laryngeal parameters between the end of the calm inspiratory phase and the breath-holding phase were statistically significant (P < 0.05), regardless of sex.

CONCLUSION

The relevant positional parameters of the vocal fold, arytenoid cartilage, and false vocal fold and their differences before and after vocal fold movement in healthy adult volunteers can be obtained objectively using TLUSG.

A single-arm, prospective study comparing translaryngeal ultrasonography with direct visualisation by flexible laryngoscopy for vocal cord assessment in patients undergoing oesophagectomy or mediastinoscopy

Background and Aims

Translaryngeal ultrasonography (TLUSG) for diagnosis of vocal cord palsy, a relatively new, safe and noninvasive bedside technique with minimal risk of respiratory infection transmission, has been effective in patients with thyroid disease. We studied its use as an alternative method to visual inspection by flexible laryngoscopy (FL) for vocal cord assessment in patients undergoing thoracic surgeries.

Methods

After Institutional Ethics Committee approval and trial registration, in this single-arm, prospective study, the vocal cord function of 110 patients who underwent either total oesophagectomy or mediastinoscopy was assessed immediately after extubation by both FL and TLUSG. A follow-up assessment was done by laryngoscopy using Hopkin's endoscope (HL) and a repeat TLUSG. The primary outcome was the concordance between direct visualisation (FL or HL) and TLUSG.

Results

Vocal cords were successfully visualised by TLUSG in 90% of male and all female patients. Findings of FL and TLUSG done at the first assessment matched in 89 (86.4%) out of 103 patients, and the degree of concordance was 0.69 (95% confidence interval [CI] =0.52-0.83). At the second assessment, HL and TLUSG findings matched in 83 (94.3%) out of 88 patients, and the degree of concordance was 0.89 (95% CI = 0.77-0.98).

Conclusion

TLUSG is an effective noninvasive alternative to direct visualisation for vocal cord assessment in both male and female patients undergoing thoracic surgery.