Preoperative Ultrasonography Assessment of Vocal Cord Movement During Thyroid and Parathyroid Surgery

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.

Utilizing Surgeon-Performed Intraoperative Translaryngeal Ultrasound for Verifying Vocal Fold Function: A Troubleshooting Approach for Intraoperative Neuromonitoring in Neck Surgery

INTRODUCTION

We investigated transcutaneous laryngeal ultrasonography (TLUS) for assessing vocal fold (VF) mobility during thyroid and parathyroid surgeries, emphasizing its precision and utility in signal loss scenarios.

METHODS

Between October 2020 and January 2023, we performed TLUS, Doppler sonography, laryngeal twitch response (LTR) palpation, and electromyography (EMG) to monitor recurrent laryngeal nerve function during neck surgeries. Postoperatively, the VF activity was verified using fiberoptic video laryngoscopy (FL). Concordance with FL was categorized based on VF activity.

RESULTS

Of the 443 VF evaluations, no instances of permanent bilateral paralysis were noted. Temporary unilateral palsy was found in 3.38% and permanent in 0.45%. TLUS displayed 97.8% agreement with EMG and was diagnostically superior (99.7% vs 98.2%) and more affordable ($68 vs $300) compared to analogous operative durations.

CONCLUSION

TLUS rivals EMG in terms of intraoperative neuromonitoring accuracy and outperforms LTR. Being cost-effective, TLUS can effectively address signal loss situations, thereby averting additional surgeries.

A Novel Thyroid Ultrasound Proficiency Metric Designed Through a Multidisciplinary Delphi Approach

BACKGROUND

Thyroid ultrasounds extend surgeons' outpatient capabilities and are essential for operative planning. However, most residents are not formally trained in thyroid ultrasound. The purpose of this study was to create a novel thyroid ultrasound proficiency metric through a collaborative Delphi approach.

METHODS

Clinical faculty experienced in thyroid ultrasound participated on a Delphi panel to design the thyroid Ultrasound Proficiency Scale (UPS-Thyroid). Participants proposed items under the categories of Positioning, Technique, Image Capture, Measurement, and Interpretation. In subsequent rounds, participants voted to retain, revise, or exclude each item. The process continued until all items had greater than 70% consensus for retention. The UPS-Thyroid was pilot tested across 5 surgery residents with moderate ultrasound experience. Learning curves were assessed with cumulative sum.

RESULTS

Three surgeons and 4 radiologists participated on the Delphi panel. Following 3 iterative Delphi rounds, the panel arrived at >70% consensus to retain 14 items without further revisions or additions. The metric included the following items on a 3-point scale for a maximum of 42 points: Positioning (1 item), Technique (4 items), Image Capture (2 items), Measurement (2 items), and Interpretation (5 items). A pilot group of 5 residents was scored against a proficiency threshold of 36 points. Learning curve inflection points were noted at between 4 to 7 repetitions.

CONCLUSIONS

A multidisciplinary Delphi approach generated consensus for a thyroid ultrasound proficiency metric (UPS-Thyroid). Among surgery residents with moderate ultrasound experience, basic proficiency at thyroid ultrasound is feasible within 10 repetitions.

Impact of completion thyroidectomy on postoperative recovery in patients with differentiated thyroid cancer

While an increasing number of patients now undergo lobectomy for low-risk differentiated thyroid cancer, a subset of patients require completion thyroidectomy to facilitate radioactive iodine therapy. Completion thyroidectomy is generally as safe as the initial operation, but a previous study showed that a longer hospitalization is required for completion thyroidectomy. In this study, we reviewed 61 consecutive patients who had been treated with an initial lobectomy and subsequent completion thyroidectomy at our institution from 2012 to 2021. We detected a changepoint in 2016 for the proportion of patients who were treated with a thyroid lobectomy (Pettitt's test P = 0.049). The rate of completion thyroidectomy remained stable throughout the study period. There was no difference in operating time, intraoperative blood loss, perioperative drop in calcium levels, and postoperative hospital stay between surgeries. The patients reported higher pain scores on the day of operation (P = 0.007) and the postoperative day 1 (P = 0.022). Occult papillary microcarcinomas were identified in the contralateral thyroid lobe in 13 (21%) patients. Multifocality was the only predictor for residual malignancy in multivariate regression. In conclusion, patients with differentiated thyroid cancer experienced more pain in the immediate postoperative period following completion thyroidectomy. Hospital stays do not change with appropriate opioid-free pain control.

Clinical usefulness of transcutaneous laryngeal ultrasonography in otolaryngology practice during COVID-19 pandemic: a literature review

As a consequence of the outbreak of SARS-CoV-2, the clinical practice of otolaryngologists underwent profound transformations. Non-aerosol-generating procedures have been researched and implemented. Transcutaneous laryngeal ultrasonography (TLUSG) provides a rapid and noninvasive method to assess laryngeal function and can support the management of laryngeal disorders. With the aim of investigating the clinical usefulness of TLUSG in otolaryngology practice, a review of the literature published on PubMed, Cochrane Library and Ovid/ Medline databases was performed up to March 2022. 38 studies were eligible to be included in the review. The selected papers were divided into six topics of interest: evaluation of vocal cords function, diagnosis of laryngeal disorders in infants and children, evaluation of swallowing disorders, assessment of laryngeal cancer and other laryngeal lesions, ultrasound-guided cricothyroidotomy, ultrasound-guided laryngeal electromyography. The results of this review demonstrated that TLUSG, applied to ENT practice, can be a valid method for dynamic laryngeal assessment and airway management, since it is time-efficient, non invasive, well tolerated and easily performed.

Laryngeal Ultrasound Detects Vocal Fold Immobility in Adults: A Systematic Review

Laryngeal ultrasound (US) is becoming widely accepted for assessing true vocal fold immobility (TVFI), a potential complication of laryngeal and thyroid surgery. The objective of this project is to perform a systematic review and meta-analysis of pooled evidence surrounding laryngeal US as a modality for diagnosing TVFI in adults at risk for the condition in comparison to laryngoscopy as a gold standard. Medical subject heading terms were used to search MEDLINE, Embase, Google Scholar, Web of Science, and the Cochrane Library for relevant citations from January 1, 2000, to June 30, 2020. Studies were included if they involved patients 16 years and older, where laryngeal US was compared to laryngoscopy for TVFI. Studies were excluded if there were insufficient data to compute a sensitivity/specificity table after attempting to contact the authors. Case reports, and case series were also excluded. The initial search returned 1357 citations. Of these, 109 were selected for review utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Thirty citations describing 6033 patients were included in the final meta-analysis. A bivariate random effects meta-analysis was performed, revealing a pooled sensitivity for laryngeal US of 0.95 (95% confidence interval [CI] 0.88-0.98), a specificity of 0.99 (95% CI 0.97-0.99), and a diagnostic odds ratio of 1328.2 (95% CI 294.0-5996.5). The area under the curve of the hierarchical summary receiver operating characteristic curve was 0.99 (95% CI 0.98-1.00). Laryngeal US demonstrates high sensitivity and specificity for detecting VFI in the hands of clinicians directly providing care to patients.

Transcutaneous Laryngeal Ultrasonography for Assessing Vocal Cord Twitch Response in Thyroid Operation during Predissection Vagus Nerve Stimulation

BACKGROUND

In this study, we aimed to report our experience with the use of intraoperative transcutaneous laryngeal ultrasonography (TLUSG) to evaluate the vocal cord twitch response during predissection vagus nerve stimulation in thyroid surgeries and examine the reliability of this technique when compared with that of laryngeal twitch palpation (LTP).

STUDY DESIGN

The prospective data collection of consecutive patients who underwent open thyroidectomy with intraoperative neuromonitoring (IONM) was reviewed retrospectively. We recorded the electromyographic activity and assessed the vocal cord twitch response on LTP, TLUSG. We compared the accessibility, sensitivity, and specificity of the techniques.

RESULTS

A total of 110 patients (38 men and 72 women) with 134 nerves at risk were enrolled. The vocal cord was assessable by TLUSG in 103 (93.6%) patients and by LTP in 64 (59.1%) patients. Two patients showed negative predissection IONM signal but positive on TLUSG and the presence of laryngeal twitch response confirmed by laryngoscopy. Fourteen patients showed positive IONM signals and presence of the vocal cord twitch response on TLUSG but not on LTP. The sensitivity and specificity were 70.21% and 100%, respectively, for LTP, and those both were 100% for TLUSG. For patients who could be assessed using both techniques, TLUSG had better accuracy than LTP (100% vs 80.33%, p = 0.0005).

CONCLUSIONS

The innovative intraoperative application of TLUSG is better for evaluating the laryngeal twitch response than LTP. This technique provides practical troubleshooting guidance for patients with no IONM signals during predissection vagus nerve stimulation.

Learning curve analysis of radiofrequency ablation for benign thyroid nodules

BACKGROUND

Radiofrequency ablation (RFA) has been increasingly accepted as an alternative to surgery in the treatment of symptomatic benign thyroid nodules. However, the learning curve of thyroid RFA has yet to be defined. We hypothesized a temporal relationship between proficiency of the skill and midterm volume reduction.

METHODS

Consecutive patients who underwent RFA and had at least a six-month follow-up were identified from an institutional database. The cumulative sum (CUSUM) analysis was applied to visualize the learning curve on the adjusted volume reduction rate (VRR).

RESULTS

A total of 102 nodules in 93 patients were included in the analysis. Linear regression revealed that nodule composition was the main predictor of the VRR. The composition-adjusted VRR increased with the chronological treatment order. The series was divided into three phases based on inflection points of the CUSUM analysis: the initial learning phase (case 1-20), consolidation phase (case 21-65), and proficiency phase (case 66-102). In the later phase, more solid nodules were treated, power output used by the operator was higher, and RFA treatment time was longer.

CONCLUSION

The treatment efficiency of thyroid RFA was associated with technical proficiency, suggesting the presence of a learning curve effect.

Computer-Analyzed Ultrasound Predictors of the Treatment Efficacy of Radiofrequency Ablation for Benign Thyroid Nodules

AIM

Radiofrequency ablation (RFA) is a relatively safe and efficient alternative to surgery for patients with benign thyroid nodules. We investigated predictive factors associated with volume reduction using digital imaging analysis.

METHODS

In this retrospective study, a prospectively maintained database containing the data of patients who received treatment from April 2019 to March 2020 was analyzed. Computerized analysis for quantitative measurement of echogenicity, heterogeneity, and the proportion of cystic components was performed on ultrasonographic images. The volume reduction rate (VRR) was calculated during follow-up. Treatment efficacy was defined as a volume reduction greater than 50% of baseline volume.

RESULTS

The median volume of 58 benign thyroid nodules before RFA was 22.7 mL. Of 53 nodules with sufficient follow-up, the median VRR was 46.4%, 61.5%, 63.4%, and 67.4% at 1, 3, 6, and 12 months, respectively. Overall, at one-year follow-up, treatment efficacy was achieved in 39 (74%) nodules. In a multivariate regression analysis, the proportion of cystic components and RFA treatment time were independently associated with treatment efficacy. A subgroup analysis focusing on solid nodules indicated a negative correlation between echogenicity and VRR.

CONCLUSIONS

The proportion of cystic components in thyroid nodules is the main predictor of RFA treatment efficacy. In solid nodules, higher echogenicity is associated with a lower volume reduction.

Transcutaneous laryngeal ultrasonography: A promising tool for otolaryngologists during COVID-19

Purpose

With the current COVID-19 outbreak, otolaryngologists are most exposed to the risk of infection due to the nature of the specialty.This is why they are required to find safer diagnostic alternatives minimizing aerosol-generating procedures. The aim of this study is to explore the accuracy of transcutaneous laryngeal ultrasonography (TLUSG) in order to assess vocal fold movement.

Materials and methods

We performed blindly both TLUSG and flexible fiberoptic laryngoscopy(FFL) on 38 patients, from March to June 2020. Patients were divided into two groups:the former with normally mobile vocal folds and the latter with unilateral vocal fold paralysis.

Results

On FFL findings, 10/38 patients (26,31%) had unilateral vocal fold paralysis; on TLUSG results, 9/38 patients (23.68%) presented impaired vocal fold motion. In comparison to laryngoscopy, the sensitivity, specificity, positive predictive value and negative predictive value of TLUSG for assessment of vocal fold mobility was 80%, 96.42%, 88.88%, 93.10% respectively. A significant association between the two techniques was found on the Chi-square test: X² = 19.7722 (p value <0.00001). Cohen's K value showed a substantial agreement: K = 0,79.

Conclusion

Although TLUSG could undoubtedly not replace laringoscopy, it represents a noninvasive and useful diagnostic tool for otolaryngologists especially during covid-19 pandemic.Data collected about its high sensitivity and specificity suggest that TLUSG could be a reliable method to screen vocal fold paralysis without performing aerosol-generating procedures, thus providing clear visualization of laryngeal real-time movements, even in non-compliant or high-risk infection patients. Our results allow us to consider TLUSG as part of the preoperative assessment of vocal folds in patients undergoing thyroidectomy.

Quantitative Ultrasound Assessment of Hyoid Bone Displacement During Swallowing Following Thyroidectomy

The aim of this study was to investigate temporal ultrasound measurements of the hyoid bone displacement during swallowing following thyroidectomy in women and to relate these measures to age, clinical outcomes, and upper digestive airway symptoms. The sample was divided into an experimental group (EG) of 20 women who underwent thyroidectomy (mean age = 49.55 years ± 15.14) and a control group (CG) of 20 healthy women volunteers (mean age = 40.75 years ± 15.92). Both groups were submitted to ultrasound assessment to obtain four temporal measurements of hyoid bone displacement during swallowing: elevation, anteriorization, maximum displacement, and maintenance of maximum displacement. In both groups, swallowing of ten milliliters of liquid and the same volume of thickened liquid (honey) were analyzed. The images were recorded on video (30 frames/second) and analyzed according to a standardized protocol. Temporal measurements of hyoid bone elevation and maximum displacement during swallowing of thickened liquid were significantly shorter in EG (p = 0.034 and p = 0.020, respectively). There were no differences in the swallowing of liquid, and no other variable was related to the ultrasound temporal measurements investigated. This study concludes that women who undergo thyroidectomy have a shorter time of hyoid bone elevation and maximum displacement during swallowing of 10 mL of thickened liquid.

Preoperative Factors Associated with Extrathyroidal Extension in Papillary Thyroid Cancer

OBJECTIVE

Extrathyroidal extension may not be accurately recognized during thyroidectomy and can increase the risk of positive margins and even recurrence. This study aimed to investigate the preoperative factors associated with extrathyroidal extension.

METHODS

We analyzed 887 patients with papillary thyroid cancer (PTC) who underwent surgery in the period of 2005-2017. Binary logistic regression analyses and generalized additive models were used to identify associations.

RESULTS

Minimal extrathyroidal extension was present in 233 (26%) patients and advanced extrathyroidal extension was found in 60 (7%) patients. Age, BMI, and tumor size were independent predictors of all or advanced extrathyroidal extension. Among the 493 patients whose BRAF mutation status was available, age (OR = 1.025), BMI (OR = 1.091), tumor size (OR = 1.544), and BRAF V600E mutation (OR = 2.311) were independently associated with extrathyroidal extension.

CONCLUSIONS

Older age, a greater BMI, a larger tumor size, and presence of the BRAF mutation were predictive of extrathyroidal extension. These factors should be taken into consideration in decision-making before surgery is performed.

Novel role of focused airway ultrasound in early airway assessment of suspected laryngeal trauma

Background

Upper airway injury secondary to blunt neck trauma can lead to upper airway obstruction and potentially cause a life-threatening condition. The most important aspect in the care of laryngeal trauma is to establish a secure airway. Focused airway ultrasound enables recognition of important upper airway structures, offers early opportunity to identify life-threatening upper airway injury, and allows assessment of the extent of injury. This information that can be obtained rapidly at the bedside has the potential to facilitate rapid intervention.

Case presentation

We report a case series that illustrate the diagnostic value of focused airway ultrasound in the diagnosis of laryngeal trauma in patients presenting with blunt neck injury.

Conclusion

Early recognition, appropriate triaging, accurate airway evaluation, and prompt management of such injuries are essential. In this case series, we introduce the potential role of focused airway ultrasound in suspected laryngeal trauma, and the correlation of these exam findings with that of computed tomography (CT) scanning, based on the Schaefer classification of laryngeal injury.

Lymphovascular invasion of papillary thyroid carcinoma revisited in the era of active surveillance

INTRODUCTION

Lymphovascular invasion (LVI) is associated with disease recurrence and compromised survival in patients with thyroid cancer. Nonetheless, LVI is not identifiable on preoperative ultrasound or cytologic assessment. We aimed to explore the clinicopathological features associated with LVI.

PATIENTS AND METHODS

We conducted a retrospective review of our prospectively maintained database from 2009 to 2018. Multivariate analyses were performed to determine the associations between clinicopathological parameters and LVI. Generalized additive models were used to examine the nonlinear relationship between continuous variables and LVI.

RESULTS

A total of 795 patients were included in the analysis, and 174 (22%) had LVI. Patients' age (odds ratio [OR] = 0.982), tumor size (OR = 1.466), clinical lymphadenopathy (OR = 6.975), and advanced extrathyroidal extension (OR = 2.938) were independently associated with LVI. In the subset analysis of 198 patients with available genetic information, tumor size (OR = 1.599), clinical lymph node metastasis (OR = 3.657), and TERT promoter mutation (OR = 4.726) were predictive of LVI. Among 573 patients who had no clinical lymphadenopathy or advanced extrathyroidal extension, tumor size was the only predictor of LVI. Tumor size >1.5 cm had an increased risk of LVI based on the generalized additive model plot and receiver operating characteristic curve analysis.

CONCLUSION

Tumor size is positively associated with the risk of LVI in papillary thyroid cancer. To avoid delayed treatment in patients with LVI, a tumor size of 1.5 cm may be considered as the safe upper limit for active surveillance.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

Is Vocal Cord Assessment before Total Thyroidectomy Required for All Patients?

We investigated whether laryngoscopy should be performed before total thyroidectomy on all patients without a history of neck surgery. A total of 2523 patients who underwent total thyroidectomy between January 1, 2013, and March 18, 2018, were retrospectively examined. Pre-operative vocal cord examination was performed on 2070 of these patients by the otorhinolaryngology department using indirect laryngoscopy. Patients with a history of neck or thyroid surgery were not included in the study. The patients were evaluated in terms of age, gender, symptom (hoarseness/dyspnea), comorbidity, surgical history, biopsy, nodule diameter, pathological diagnosis, and tracheal deviation. Preoperative vocal cord paralysis was detected in 0.8 per cent of the patients (17/2070). Four patients (23.5%) were male and 13 patients (76.5%) were female. The mean age was 62 (range, 25–82) years. Seven of the 17 patients (41%) were symptomatic, with complaints of dyspnea in five and hoarseness in two. The univariate analysis revealed that a nodule diameter >30 mm and the presence of dyspnea were associated with vocal cord damage. Furthermore, the multivariate analysis showed that dyspnea alone was an independent variable ( P = 0.011). It is recommended that preoperative vocal cord evaluation should be performed only in patients with severe symptoms, such as dyspnea.

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

OBJECTIVE

This review set out to examine the applicability of transcutaneous laryngeal ultrasonography (TLUSG) for the assessment of laryngeal function after thyroidectomy.

METHODS

An integrative review of the literature was performed using Medline/PubMed, LILACS, and SciELO databases. The methodological quality of the studies was analyzed using the appraisal tool for cross-sectional studies.

RESULTS

All 8 included articles investigated laryngeal function with regard to the risk of vocal fold immobility after thyroidectomy. The results regarding the diagnostic power of TLUSG for this assessment are controversial, and there is a tendency to use this examination as a screening procedure for subsequent confirmation by flexible laryngoscopy.

CONCLUSIONS

Transcutaneous laryngeal ultrasonography is a viable, noninvasive, and useful tool to assess laryngeal function after thyroidectomy, but current available evidence suggests that it does not replace flexible laryngoscopy for the diagnosis of vocal fold immobility.

Assessment of vocal fold mobility using dynamic magnetic resonance imaging and ultrasound in healthy volunteers

PURPOSE

To verify the value of dynamic magnetic resonance imaging (MRI) sequences, fast field echo (FFE), and balanced gradient echo (true fast imaging with steady-state free precession - TRUFI) in the evaluation of vocal fold mobility in healthy volunteers, against ultrasound examination (US) as the reference test.

MATERIAL AND METHODS

Vocal fold mobility in 35 healthy volunteers (age 20-59 years, 20 women and 15 men) with no history of laryngeal disorders and neck surgeries was determined by means of US and MRI during normal breathing and phonation of the "hiiii" sound. US images were used to determine the glottic angles. During MRI two dynamic sequences, fast field echo and balanced gradient echo, were applied to determine the minimum and maximum values of the glottic angles, along with the rima glottidis area, separately for the right and left compartments. Due to differences in larynx anatomy, the abovementioned parameters were analysed separately for women and men.

RESULTS

No significant differences were observed between the glottic angle values obtained during US and dynamic MRI (FFE and TRUFI sequences). Regardless of the dynamic MRI sequence used, a positive correlation was found between the maximum values of glottic angle and the rima glottidis area. This correlation was strong and statistically significant among men, but not in women.

CONCLUSIONS

Dynamic MRI of vocal folds using FFE and TRUFI sequence is an accurate method for the objective evaluation of rima glottidis width.

Functional analysis of vocal folds by transcutaneous laryngeal ultrasonography in patients undergoing thyroidectomy

BACKGROUND

Transcutaneous laryngeal ultrasound (TCLUS) can assess Vocal folds (VF) by subjectively identifying mobility or objectively by calculating vocal fold displacement velocity (VFDV). Optimal diagnostic approach (subjective assessment, VFDV estimation or a combination of both) is unresolved; hence, we conducted this prospective study in patients undergoing thyroidectomy.

METHOD

Two anaesthetists performed TCLUS pre- and post-operatively for functional assessment of 200 VFs on 100 patients. Their findings were compared with pre-operative flexible laryngoscope (FL) performed by surgeons and with post-operative C-Mac video laryngoscope (C-Mac VL) by another independent anaesthetist. Correlation between FL and TCLUS findings and inter-rater agreement between TCLUS findings of both anaesthetists was analysed. Decision curve analysis (DCA) was performed to compare clinical benefit of hoarseness, subjective VF movement, VFDV, and combined assessment for detecting disabled VFs.

RESULTS

We found good correlation between VF mobility on TCLUS and FL (Spearman's r = 0.93, P < 0.0001) as well as C-Mac VL (Spearman's r = 0.83, P < 0.0001) with excellent inter-rater agreement between both anaesthetists. DCA showed combined assessment to have marginally higher clinical benefit than other diagnostic approaches at intermediate threshold probabilities while its benefit was similar to subjective evaluation at higher threshold probabilities.

CONCLUSION

Provided achievement of optimal acoustic window, TCLUS can reliably assess disabled VFs with FL reserved for their confirmation or doubtful cases. Subjective assessment of VF mobility should suffice in most cases with additional VFDV estimation reserved pre-operatively for situations with higher risk of VFs disability, and post-operatively when subjective VF assessment findings are discordant from pre-operative status.

Recurrent laryngeal nerve injury assessment by intraoperative laryngeal ultrasonography: a prospective diagnostic test accuracy study

Introduction

Recurrent laryngeal nerve injury is one of the major complications related to thyroid surgery. Intraoperative recurrent laryngeal nerve functional status monitoring is becoming a standard part of thyroid surgery. However, the current methods for intraoperative nerve functional status assessment are associated with a demand for specialized devices and increased costs.

Aim

To assess the validity of a new method – intraoperative laryngeal ultrasonography – for prediction of recurrent laryngeal nerve injury.

Material and methods

This prospective diagnostic test accuracy study included 112 patients undergoing thyroid surgery in Vilnius University Hospital Santaros Clinics. Neurostimulation combined with laryngeal ultrasonography and laryngeal palpation was performed intraoperatively to evaluate recurrent laryngeal nerve functional status. Recurrent laryngeal nerve injury was confirmed by laryngoscopy, which was performed on the first postoperative day and considered to be the gold standard method.

Results

Data on 112 consecutive patients and 200 nerves at risk were collected. The temporary vocal cord palsy rate was 5.4% per patient and 3% per nerve at risk. No permanent palsy or bilateral injury cases were registered in the study cohort. Laryngeal ultrasound sensitivity counted per nerve at risk was 83.3%, specificity 97.2%, accuracy 96.4%, positive predictive value 62.5% and negative predictive value 99%.

Conclusions

Laryngeal ultrasonography is a feasible new technique for accurate intraoperative recurrent laryngeal nerve injury evaluation.

Validation of ultrasound as a diagnostic tool to assess vocal cord motion in an animal feasibility study

Background

Post-thyroidectomy dysphonia can result from recurrent laryngeal nerve (RLN) injury. Confirmation of postoperative recurrent nerve function has prompted many surgeons to advocate laryngoscopic examination. Indirect and flexible laryngoscopy permit visualization of vocal cord motion, but not all thyroid surgeons are skilled in these techniques. Indirect laryngoscopy has a significant failure rate due to gag reflexes or anatomical obstruction. Flexible fiberoptic laryngoscopy, the current gold standard, allows reliable visualization of the cords, but perioperative examination is not always feasible for lack of equipment or training. Recent studies suggest vocal fold ultrasound as an alternative to flexible laryngoscopy. It offers the advantages of being non-invasive and painless without radiation exposure or sedation. Whereas ultrasound has been compared to laryngoscopy in the clinical setting, there remains a need for correlation of laryngeal ultrasound results with known neurophysiology in the normal and injured state. An animal model was proposed that reproduces neck surgery-associated recurrent nerve injury. The model allowed simultaneous recording of laryngeal endoscopy and transcutaneous high-resolution ultrasound during stimulation of intact and injured RLNs.

Methods

One RLN was injured in each of 4 rats. Rats were kept anesthetized during the fiberoptic examination and laryngeal ultrasound procedures. Following surgery and subsequent imaging the rats were given a lethal anesthetic dose. Results of both imaging modalities were compared to the presence or absence of neuromuscular action potential following stimulation of the recurrent nerve.

Results

The investigators observed a 100% correlation between endoscopic and ultrasonographic assessments.

Conclusions

This study validated the clinical use of diagnostic ultrasound in vocal cord dysfunction in a rodent model.

A Novel Lateral Approach to the Assessment of Vocal Cord Movement by Ultrasonography

BACKGROUND

Ultrasonography is a non-invasive technique that is commonly used by endocrinologists and endocrine surgeons to examine the thyroid region and could be useful for the assessment of vocal cord movement by these specialists. However, previous studies reported a low rate of successful visualization of vocal cord movement by ultrasonography. To address this issue, we devised a novel ultrasonographic procedure for assessing vocal cord movement indirectly by observing the arytenoid movement from a lateral view.

METHODS

Subjects were 188 individuals, including 23 patients with vocal cord paralysis and 13 with vocal cord paresis. We performed ultrasonographic assessment of vocal cord movement using two different procedures: the conventional middle transverse procedure and the novel lateral vertical procedure.

RESULTS

The rate of visualization of vocal cords with the middle transverse procedure was 70.2% and that of the arytenoid cartilage with the lateral vertical procedure was 98.4%. The lateral vertical procedure enabled visualization of all patients with vocal cord paresis/paralysis and detected all 23 patients with vocal paralysis; only one of 13 patients with vocal cord paresis was positively identified. The conventional procedure enabled visualization of 21 of 36 patients with vocal cord paresis/paralysis with high accuracy. There was no false-positive case in either procedure.

CONCLUSION

The proposed lateral vertical procedure improved the rate of visualization of vocal cord movement by ultrasonography, suggesting that it is a useful technique to screen for vocal cord paralysis by ultrasonography.

Anatomic factors affecting the use of ultrasound to predict vocal fold motion: A pilot study

PURPOSE

Ultrasonography is a well-established modality for visualization of head and neck anatomy. Using ultrasound to detect vocal fold mobility has been described before, but no study has evaluated factors affecting the exam reliability. The aim of the study is to determine anatomic factors influencing the reliability of ultrasound to detect vocal fold motion. Methods and materials Patients underwent ultrasound evaluation and flexible laryngoscopy to assess vocal fold motion from August 2015 to March 2016. Length, accuracy, and clarity of ultrasound examination were assessed, compared to flexible laryngoscopy. For patients with prior neck CT scan imaging, laryngeal anatomy was independently assessed by a blinded neuroradiologist.

RESULTS

A total of 23 patients, 21 with bilateral vocal fold motion and two with unilateral paralysis, were enrolled. Vocal folds were visible in 19 patients (82%). Eight patients (42%) had good/excellent view and 11 patients (58%) had fair/difficult view. The ultrasound correctly detected absent movement of the vocal fold in the two patients with unilateral paralysis. A total of 19 patients had CT scans, and a linear correlation (r² = 0.65) was noted between the anterior thyroid cartilage angle measured on CT and the grade of view on ultrasound.

CONCLUSION

Ultrasound was able to detect vocal fold motion in 82% of randomly screened patients. Ease of detection of vocal fold motion correlated with the anterior thyroid angle. Further studies are warranted to investigate the reproducibility of our results and how this might impact use of ultrasound for detection of vocal fold motion in the operative setting.

Reconsideration of tumor size threshold for total thyroidectomy in differentiated thyroid cancer

BACKGROUND

The optimal extent of surgery for differentiated thyroid cancer may not be well recognized initially. Identification of intermediate-risk features on surgical pathology may prompt the need for completion thyroidectomy if a lobectomy is performed. In this study, we examined the factors in relation to the need for completion thyroidectomy.

METHODS

We studied consecutive patients who underwent thyroidectomy for differentiated thyroid cancer from 2008 to 2017. Total thyroidectomy was indicated when tumor size >4 cm, clinical extrathyroidal extension, clinical lymph node metastasis, or distant metastasis was present. The need for completion thyroidectomy was defined as the presence of aggressive histology, extrathyroidal extension, lymphovascular invasion, or non-low-risk nodal metastasis.

RESULTS

Among 771 patients, 155 (20%) were definitely indicated for total thyroidectomy. The need for completion thyroidectomy was identified in 273 (44%) of the 616 patients initially eligible for lobectomy. The proportions of patients requiring completion thyroidectomy were 18% and 57% for microcarcinomas and tumors of 1-4 cm, respectively. Receiver operating characteristic curve analysis indicated that tumor size ≥1.1 cm had the highest accuracy of prediction. Multivariate logistic regression revealed that tumor size and BRAF V600E mutation were independent factors predicting the risk of requiring completion thyroidectomy.

CONCLUSION

A substantial portion of patients with differentiated thyroid cancer who are preoperatively eligible for lobectomy would be found to have intermediate-risk pathologic features. This should be incorporated into the shared decision making before surgery.

Point-of-care ultrasound (POCUS) of the upper airway

Airway management is a critical skill in the practice of several medical specialities including anesthesia, emergency medicine, and critical care. Over the years mounting evidence has showed an increasing role of ultrasound (US) in airway management. The objective of this narrative review is to provide an overview of the indications for point-of-care ultrasound (POCUS) of the upper airway. The use of US to guide and assist clinical airway management has potential benefits for both provider and patient. Ultrasound can be utilized to determine airway size and predict the appropriate diameter of single-lumen endotracheal tubes (ETTs), double-lumen ETTs, and tracheostomy tubes. Ultrasonography can differentiate tracheal, esophageal, and endobronchial intubation. Ultrasonography of the neck can accurately localize the cricothyroid membrane for emergency airway access and similarly identify tracheal rings for US-guided tracheostomy. In addition, US can identify vocal cord dysfunction and pathology before induction of anesthesia. A rapidly growing body of evidence showing ultrasonography used in conjunction with hands-on management of the airway may benefit patient care. Increasing awareness and use of POCUS for many indications have resulted in technologic advancements and increased accessibility and portability. Upper airway POCUS has the potential to become the first-line non-invasive adjunct assessment tool in airway management.

Point-of-Care Sonographic Findings in Acute Upper Airway Edema

We describe a case where a patient presented with acute angiotensin-converting enzyme inhibitor (ACE-I) induced angioedema without signs or symptoms of upper airway edema beyond lip swelling. Point-of-care ultrasound (POCUS) was used as an initial diagnostic test and identified left-sided subglottic upper airway edema that was immediately confirmed with indirect fiberoptic laryngoscopy. ACE-I induced angioedema and the historical use of ultrasound in evaluation of the upper airway is briefly discussed. To our knowledge, POCUS has not been used to identify acute upper airway edema in the emergency setting. Further investigation is needed to determine if POCUS is a sensitive and specific-enough tool for the identification and evaluation of acute upper airway edema.

Laryngeal examination in thyroid and parathyroid surgery: An American Head and Neck Society consensus statement: AHNS Consensus Statement

This American Head and Neck Society (AHNS) consensus statement discusses the techniques of laryngeal examination for patients undergoing thyroidectomy and parathyroidectomy. It is intended to help guide all clinicians who diagnose or manage adult patients with thyroid disease for whom surgery is indicated, contemplated, or has been performed. This consensus statement concludes that flexible transnasal laryngoscopy is the optimal laryngeal examination technique, with other techniques including laryngeal ultrasound and stroboscopy being useful in selected scenarios. © 2016 Wiley Periodicals, Inc. Head Neck 38: 811-819, 2016.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

The Role of Airway and Endobronchial Ultrasound in Perioperative Medicine

Recent years have witnessed an increased use of ultrasound in evaluation of the airway and the lower parts of the respiratory system. Ultrasound examination is fast and reliable and can be performed at the bedside and does not carry the risk of exposure to ionizing radiation. Apart from use in diagnostics it may also provide safe guidance for invasive and semi-invasive procedures. Ultrasound examination of the oral cavity structures, epiglottis, vocal cords, and subglottic space may help in the prediction of difficult intubation. Preoperative ultrasound may diagnose vocal cord palsy or deviation or stenosis of the trachea. Ultrasonography can also be used for confirmation of endotracheal tube, double-lumen tube, or laryngeal mask placement. This can be achieved by direct examination of the tube inside the trachea or by indirect methods evaluating lung movements. Postoperative airway ultrasound may reveal laryngeal pathology or subglottic oedema. Conventional ultrasound is a reliable real-time navigational tool for emergency cricothyrotomy or percutaneous dilational tracheostomy. Endobronchial ultrasound is a combination of bronchoscopy and ultrasonography and is used for preoperative examination of lung cancer and solitary pulmonary nodules. The method is also useful for real-time navigated biopsies of such pathological structures.

Clinical Usefulness of Ultrasonography-Guided Laryngeal Electromyography

OBJECTIVES/HYPOTHESIS

To investigate the proper approach and technical method of ultrasonography-guided laryngeal electromyography (US-guided LEMG).

STUDY DESIGN

This is a prospective study.

METHODS

Twenty patients who underwent US-guided LEMG were enrolled. US-guided LEMG was cooperatively performed by one otolaryngologist, one neurologist, and one radiologist. The location of the needle electrode was confirmed with US after electrode insertion into the laryngeal intrinsic muscle. The US transducer was applied on the neck by a transverse/midline and transverse/oblique approach to identify the cricothyroid (CT), thyroarytenoid (TA) muscles, and the location of the needle electrode.

RESULTS

CT muscles were easily identified on US in all 20 patients. TA muscles were identified in 17 patients (85%). The transverse/oblique approach was helpful to detect TA muscle in case of calcified thyroid cartilage or anatomic variation.

CONCLUSIONS

US-guided LEMG, which enables the exact insertion of the needle electrode, improves the reliability of examination and is helpful in early detection and to prevent complications.

The progression of thyroid cartilage calcification as it relates to the utilization of laryngeal ultrasound

OBJECTIVES/HYPOTHESIS

The purpose of this study is to review the computed tomography (CT) scans of infants, children, and adults to assess the degree of calcification of the thyroid cartilage at various ages in order to understand in which age group laryngeal ultrasound can be utilized.

STUDY DESIGN

Retrospective.

METHODS

Two hundred patients from newborn to 50 years who received a CT scan of the neck were identified. The Hounsfield units (HU) of the thyroid cartilage were calculated at one o'clock, four o'clock, eight o'clock, and eleven o'clock at the level of the true and false vocal fold. The Spearman correlation coefficient was calculated to evaluate the correlation between each measure and age, then a linear regression with a logarithmic transformation was applied to further study how the measures were related to age.

RESULTS

The Spearman correlation coefficients ranged from 0.58 to 0.75. The P values of these coefficients were all < 0.0001, showing a significant relationship to age. The age increase by 1 year resulted in increased calcification by 1.5% to 4%. The Wilcoxon signed rank test compared the rate of calcification at each site measured. This showed that the two posterolateral sites calcify faster than the two anteromedial sites.

CONCLUSION

The thyroid cartilage calcifies at a rate that is significantly related to increasing age and calcifies in a posterolateral to anteromedial direction. Based on the HU, the thyroid cartilage is not consistently denser than soft tissue until greater than 40 years of age, which would make laryngeal ultrasound feasible for this population.

LEVEL OF EVIDENCE

4.