Transcutaneous Laryngeal Ultrasonography for the Assessment of Laryngeal Function After Thyroidectomy: A Review

Transcutaneous Laryngeal Ultrasound for Assessing Hyaluronic Acid Status in Patients Undergoing Injection Laryngoplasty

OBJECTIVE

Injection laryngoplasty (IL) with hyaluronic acid (HA) is an effective treatment for patients with glottic insufficiency. The duration of HA maintenance in the vocal fold remains unknown. In this study, transcutaneous laryngeal ultrasound (TLUS) was used to evaluate the absorption and migration of HA after IL. Subsequent management might be provided based on the TLUS finding.

METHODS

Patients diagnosed with unilateral vocal fold paralysis (UVFP) or vocal fold atrophy were recruited. All patients underwent IL with HA in an office-based setting along with TLUS to monitor the status of HA. The schedule of TLUS included assessments before and after IL until non-visualization.

RESULTS

The study population comprised 38 women and 17 men. Of the patients, 54.1% underwent IL for UVFP, whereas 45.9% underwent IL for vocal fold atrophy. Multivariate Cox regression analysis for factors affecting HA absorption revealed that the cause of injection was the most important independent predictor (hazard ratio [HR], 2.15; 95% confidence interval [CI], 1.03-4.46; p = 0.040). The duration of HA maintenance was significantly longer in patients with UVFP than in those with vocal fold atrophy (8.77 vs. 4.70 months, HR, 2.33; 95% CI, 5.47-8.18; p = 0.002).

CONCLUSION

TLUS is an objective assessment method for patients undergoing IL with HA. Subsequent tailor-made management could be offered based on the TLUS findings during follow-up. For patients at high risk of upper respiratory tract infection or who are intolerant to flexible nasopharyngoscopy, TLUS can be used as an alternative tool to evaluate the condition of the glottis after IL with HA.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:4682-4687, 2024.

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.

Assessment of pre-extubating recurrent laryngeal nerve palsy using ultrasound in postoperative patients with esophageal cancer: a prospective observational study

PURPOSE

Ultrasound performed after extubation has been suggested to be useful for the diagnosis of recurrent laryngeal nerve (RLN) paralysis. However, the use of ultrasound for this purpose before extubation has not been examined. The aim of this study was to examine the versatility (interrater reliability) and usefulness of ultrasound for evaluating the movement of vocal cords before extubation.

METHODS

The subjects were 30 patients who underwent radical surgery for esophageal cancer from August 2020 to December 2021. An experienced examiner performed an ultrasound examination before and after elective extubation on the day after surgery to evaluate RLN paralysis and record videos. Bronchoscopy was then performed to make a definite diagnosis. Three anesthetists blinded to the diagnosis also evaluated the cases using the videos, and the versatility of the examination was determined using a kappa test.

RESULTS

The diagnostic accuracies of the examiner and three anesthetists were 76.7%, 50.0%, 53.3%, and 46.7%, respectively, and the kappa coefficients for the examiner with the anesthetists were 0.310, 0.502, and 0.169, respectively. The sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of RLN paralysis by the examiner using ultrasound before extubation were 0.57, 0.95, 0.80, and 0.87, respectively.

CONCLUSION

These results indicate a lack of versatility of the ultrasound examination based on the low kappa coefficients. However, with an experienced examiner, ultrasound can serve as a non-invasive examination that can be performed before extubation with high accuracy and specificity for diagnosis of postoperative RLN paralysis.

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.

Ultrasound-guided core needle biopsy for accessing laryngeal masses with unsatisfactory laryngoscopy and biopsy results

BACKGROUND

Laryngoscopy and biopsy is the standard techniques to sample and diagnose laryngeal neoplasms, but not all patients with laryngeal neoplasm are eligible for biopsy via laryngoscopy (e.g., submucosal neoplasms).

PURPOSE

This study was conducted to evaluate the feasibility and diagnostic yield of ultrasound-guided core needle biopsy (US-CNB) for submucosal laryngeal neoplasms with unsatisfactory laryngoscopy and biopsy results.

METHODS

We retrospectively reviewed the medical records of 24 patients with unsatisfactory laryngoscopy and biopsy results who were referred to our center for US-CNB from January 2017 to November 2021. For all enrolled patients, we assessed consistency between the laryngoscopic biopsy, US-CNB, and final results. The final results were determined from the surgical biopsy results or clinical follow-up information (at least 3 month). Differences between biopsy techniques were compared using the Fisher's exact test. A P value less than 0.05 indicated statistical significance.

RESULTS

Twenty-four patients (median [range] age: 60.6 [41-76] years, 20 men) were included in our study. Among the 24 patients, 12 were eligible for laryngoscopic biopsy. In total, 24 patients underwent 26 US-CNB. Two patients underwent a repeat US-CNB for conformation of a benign histological result or due to inadequate specimen collection. The results of laryngoscopic biopsy and US-CNB were compared with the final result. The overall accuracy of US-CNB for differentiating benign from malignant lesions was 95.8 % (23/24), and this procedure had a sensitivity, specificity, positive predictive value, and negative predictive value of 95.2 %, 100 %, 100 %, and 75 %, respectively. The results of US-CNB are significantly better than those of laryngoscopic biopsy.

CONCLUSIONS

US-CNB is a safe, effective, and feasible technique for investigating suspicious submucosal laryngeal neoplasms and can serve as a complementary method for early and timely diagnosis of those neoplasms.

[Polypositional transcutaneous ultrasound assessment of vocal folds mobility. Ultrasonographic sign of laryngeal dysfunction]

Fiberoptic laryngoscopy is a standard procedure for evaluation of vocal folds immobility. However, this method is invasive, requires special qualifications and technical equipment, which limits its routine use. Therefore, in daily practice, the vast majority of laryngoscopy are performed by an indirect way, the accuracy of which depends on the specialist experience and the patient compliance. On the other hand, a large number of patients require for a convenient, non-invasive and inexpensive approach to assess the vocal folds mobility. The transcutaneous laryngeal ultrasonography can be such a method. However, the disadvantage of this technique is low informative value.

OBJECTIVE

To increase the effectiveness of the diagnosis of laryngeal dysfunction using transcutaneous laryngeal ultrasonography.

MATERIAL AND METHODS

Patients underwent laryngeal ultrasonography and videolaryngoscopy before and after thyroid or parathyroid surgery. Ultrasound was performed polypositionally in the transverse and oblique planes. Functional tests with breathing and breath holding were used. Qualitative (the smile or flying bird signs, the vertical closing line of the vocal folds, synchronicity and symmetry movement of the arytenoid cartilages) and quantitative (the length contraction of the vocal cord, the rotation angle of the arytenoid cartilage) ultrasonic parameters determin the normal vocal folds mobility.

RESULTS

996 patients were included in the study. Vocal folds paresis was detected in 106 (10.6%) patients. In 72 (7.2%) cases partial impaired mobility of the vocal folds (laryngeal dyskinesia) were detected. The echographic patterns of these patients were analyzed. Qualitative ultrasound signs of laryngeal dysfunction were identified: a crooked smile or falling bird signs, a closing line deformation of the vocal folds, an arytenoid immobility. Quantitative ultrasound signs included: a decrease in the length contraction of the vocal cord and a reduction of rotation angle of the arytenoid cartilage. Unilateral laryngeal paresis was diagnosed in 101 (10.1%) patients. In unilateral disorders the rotation angle of the arytenoid on the affected side was 0-14° and the length contraction of the vocal cord was 0-1.8 mm. A crooked smile or falling bird signs, a closing line deformation of the vocal folds and immobility of the arytenoid cartilages were also determined. In 5 (0.5%) cases bilateral laryngeal paresis was revealed, in which on both sides the rotation angles of the arytenoid were 0-14°, and the length contraction of the vocal cords was 0-1.8 mm. At the same time there was no a smile or flying bird signs and a closing line of the vocal folds. Laryngeal dyskinesia was characterized by a crooked smile or falling bird signs and a closing line deformation of the vocal folds. At the same time, partial mobility of the arytenoid cartilage was noted in comparison with the contralateral side (there was a difference in the rotation angle of the arytenoid between the right and left sides of 15 ° or more degrees).

CONCLUSION

The sensitivity and specificity polypositional ultrasound of the vocal folds in women were 100% and 99.8%, in men - 85.7% and 99.2%, respectively.

Cervical ultrasound for the evaluation of the vocal cords: A pilot study in an endocrine surgery unit

INTRODUCTION

Cervical ultrasound (CE) has emerged as a promising tool in recent years for vocal cord (VC) assessment in patients undergoing thyroid surgery. Our aim is to assess the reliability of CE once implemented in an endocrine surgery unit and performed by the surgeons themselves.

MATERIAL AND METHOD

86 participants with no history of laryngeal pathology or cervical surgery underwent CE by three independent endocrine surgeons. Laryngeal structures and specifically the VCs were analysed. To consider the examination as diagnostic, the VCs had to be visualised statically and during phonation. The time taken to perform the technique and the interobserver variability were also analysed.

RESULTS

Of the 86 participants, 51.2% were male with a mean age of 43 years. The range of diagnostic examinations between surgeons was 60-68%, with substantial agreement between the 3 explorers (Fleiss's K-value = .714). Male sex and advanced age were factors associated with non-assessability of the technique. The mean procedure time was 72 s.

CONCLUSIONS

CE is a fast, non-invasive, feasible bedside tool useful for the assessment of VCs prior to thyroid surgery, mainly in young women.

Translating Ultrasound into Clinical Practice for the Assessment of Swallowing and Laryngeal Function: A Speech and Language Pathology-Led Consensus Study

Ultrasound (US) has an emerging evidence base for the assessment of swallowing and laryngeal function. Accessibility and technological advances support the use of US as a clinical assessment tool; however, there is insufficient evidence to support its translation into clinical practice. This study aimed to establish consensus on the priorities for translation of US into clinical practice for the assessment of swallowing and laryngeal function. Nominal Group Technique (NGT) was used as a formal method of consensus development. Clinicians and academics, all members of an international US working group, were invited to participate in the study. Two NGT meetings were held, where participants silently generated and then shared ideas. Participants anonymously ranked items. Rankings were aggregated before participants re-ranked items in order of priority. Discussions regarding rankings were recorded and transcribed to inform analysis. Member-checking with participants informed the final analysis. Participants (n = 15) were speech and language pathologists, physiotherapists and sonographers representing six countries. Fifteen items were identified and prioritised 1-13 (including two equally ranked items). Reliability, validity and normative data emerged as key areas for research while development of training protocols and engagement with stakeholders were considered vital to progressing US into practice. Analysis revealed common themes that might be addressed together in research, in addition to the ranked priority. A measured approach to the translation of US into clinical practice will enable effective implementation of this tool. Priorities may evolve as clinical and professional contexts shift, but this study provides a framework to advance research and clinical practice in this field.

Transcutaneous Laryngeal Ultrasound for Vocal Cord Paralysis Assessment in Patients Undergoing Thyroid and Parathyroid Surgery-A Systematic Review and Meta-Analysis

Recurrent laryngeal nerve injury is an important complication following thyroid and parathyroid surgery. Recently, Transcutaneous laryngeal ultrasound (TLUSG) has emerged as a non-invasive alternative to laryngoscopic examination for vocal cord (VC) assessment. The aim of the systematic review and meta-analysis was to determine its diagnostic accuracy in reference to laryngoscopy. It was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. MEDLINE, Scopus, Cochrane library and Web of Science databases were searched to identify relevant articles. Sixteen studies were included in the review. Pooled diagnostic accuracy was calculated based on weighted arithmetic mean and plotting forest plot. The pooled visualization rate was 86.28% and 94.13% preoperatively and postoperatively, respectively. The respective pooled sensitivity and specificity was 78.48% and 98.28%, and 83.96% (CI 95%: 77.24-88.50%) and 96.15% (CI 95%: 95.24-96.88%). The diagnostic accuracy improved if transverse and lateral approaches, and valsalva maneuver were utilized. Male gender and older age were the most crucial risk factors for VC non-visualization. TLUSG is an efficacious screening tool for vocal cord palsy due to its high sensitivity. It is likely to prevent unnecessary laryngoscopic examination in around 80% of patients, with the potential for becoming a gold standard for specific (female/young) patient cohort through assimilative modifications use, increasing expertise and development of objective measurements in the future.

Ultrasound diagnosis of a case of transient bilateral vocal cord paralysis secondary to local anesthetic infiltration

One of the most important complications associated with thyroid and parathyroid surgery is vocal cord paralysis due to a recurrent laryngeal nerve injury. Recurrent laryngeal nerve injury paralysis induced by local anesthetics is a rare complication with very few published cases Various techniques are available for diagnosing vocal cord paralysis, including, flexible fiberoptic laryngoscopy, videostrobolaryngoscopy and indirect laryngoscopy. However, these techniques are expensive and are often associated with pain and discomfort among patients. Considering these disadvantages, transcutaneous laryngeal ultrasound is an alternative imaging tool for vocal cord examination in patients undergoing thyroid and parathyroid surgery. We describe a case which was sonographically diagnosed a transient bilateral vocal cord paralysis after the local infiltration of 10mL of 2% mepivacaine administered for the revision of the surgical wound due to a subcutaneous hematoma that occurred after a subtotal parathyroidectomy.