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.

Fluorescence imaging to visualize the recurrent laryngeal nerve during thyroidectomy procedures: analysis of 65 cases and 81 nerves.

BACKGROUND: Recurrent laryngeal nerve (RLN) injury after thyroidectomy is relatively common. Locating the RLN prior to thyroid dissection is paramount to avoid injury. We developed a fluorescence imaging system that permits nerve autofluorescence. We aimed to determine the sensitivity and specificity of fluorescence imaging at detecting the RLN relative to thyroid and other background tissue and compared it to white light. METHODS: In this prospective study, 65 patients underwent thyroidectomy from January to April 2022 (16 bilateral thyroid resections) using white and fluorescent light. Fluorescence intensity [relative fluorescence units (RFU)] was recorded for RLN, thyroid, and background. RFU mean, minimum, and maximum values were calculated using Image J software. Thirty randomly selected pairs of white and fluorescent light images were independently reviewed by two examiners to compare RLN detection rate, number of branches, and length and minimum width of nerves visualized. Parametric and nonparametric statistical analysis was performed. RESULTS: All 81 RNLs observed were visualized more clearly under fluorescence (mean intensity, µ = 134.3 RFU) than either thyroid (µ = 33.7, p < 0.001) or background (µ = 14.4, p < 0.001). Forest plots revealed no overlap between RLN intensity and that of either other tissue. Sensitivity and specificity for RLN were 100%. All 30 RLNs and all 45 nerve branches were clearly visualized under fluorescence, versus 17 and 22, respectively, with white light (both p < 0.001). Visible nerve length was 2.5 × as great with fluorescence as with white light (µ = 1.90 vs. 0.76 cm, p < 0.001). CONCLUSIONS: In 65 patients and 81 nerves, RLN detection was markedly and consistently enhanced with autofluorescence neuro-imaging during thyroidectomy, with 100% sensitivity and specificity.

Cardiovocal Syndrome - An Aortic Arch Aneurysm As A Rare Cause Of Vocal Cord Paralysis.

INTRODUCTION: Cardiovocal or Ortner's syndrome is a rare cause of vocal cord paralysis. Damage to the left recurrent laryngeal nerve may be caused by an aortic arch aneurysm, in even rarer cases. CLINICAL CASE: A 60-year-old woman presented with hoarseness lasting for six months. Paralysis of the left vocal cord was confirmed with laryngoscopy and an aortic arch aneurysm was diagnosed on chest CT. Despite correction of the aortic aneurysm, her hoarseness did not improve. DISCUSSION: Mediastinal disease may cause vocal cord paralysis, due to the intrathoracic course of the recurrent laryngeal nerve. The assessment of the superior mediastinum on CT is mandatory in these cases. In cardiovocal syndrome, cardiovascular diseases damage the recurrent laryngeal nerve. Aortic aneurysms are a rare cause of Ortner's, especially when they affect the distal portion of the aortic arch and stretch the left recurrent laryngeal nerve at the aortopulmonary window.

A Novel Scoring System for Predicting the Metastases of Posterior Right Recurrent Laryngeal Nerve Lymph Node Involvement in Patients With Papillary Thyroid Carcinoma by Preoperative Ultrasound.

Objective: Our goal was to investigate the correlation between papillary thyroid carcinoma (PTC) characteristics on ultrasonography and metastases of lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN). There is still no good method for clinicians to judge whether a patient needs LN-prRLN resection before surgery, and we also wanted to establish a new scoring system to determine whether patients with papillary thyroid carcinoma require LN-prRLN resection before surgery. Patients and Methods: There were 482 patients with right or bilateral PTC who underwent thyroid gland resection from December 2015 to December 2017 recruited as study subjects. The relationship between the PTC characteristics on ultrasonography and the metastases of LN-prRLN was analyzed by univariate and logistic regression analyses. Based on the risk factors identified in univariate and logistic regression analysis, a nomogram-based LN-prRLN prediction model was established. Result: LN-prRLN were removed from all patients, of which 79 had LN-prRLN metastasis, with a metastasis rate of 16.39%. Multivariate logistic regression analysis revealed that LN-prRLN metastasis was closely related to sex, age, blood supply, larger tumors (> 1 cm) and capsular invasion. A risk prediction model has been established and fully verified. The calibration curve used to evaluate the nomogram shows that the consistency index was 0.75 ± 0.065. Conclusion: Preoperative clinical data, such as sex, age, abundant blood supply, larger tumor (> 1 cm) and capsular invasion, are positively correlated with LN-prRLN metastasis. Our scoring system can help surgeons non-invasively determine which patients should undergo LN-prRLN resection before surgery. We recommend that LN-prRLN resection should be performed when the score is above 103.1.

Third branchial cleft cyst as a cause of hoarseness: a case report.

Third branchial cleft cyst is a rare congenital disease of the neck. It presents as a painless mass that develops rapidly in the neck following an infection. This is the first case report of recurrent laryngeal nerve palsy caused by a third branchial cleft cyst. A 30-year-old woman presented with a 3-month history of hoarseness as her only symptom; she had no pain, fever, dysphagia, dyspnoea, or palpable neck mass. Laryngoscopy revealed that her right vocal cord was paralyzed. Computed tomography and magnetic resonance imaging revealed a cystic mass in the right tracheoesophageal groove that was closely associated with the trachea. Intraoperatively, the cyst was found not to originate from the thyroid or trachea, but it was compressing the right recurrent laryngeal nerve. The hoarseness resolved the day after the cyst was removed.

Diagnosis of recurrent laryngeal nerve paralysis following esophagectomy by evaluating movement of the vocal cords and arytenoid cartilages using ultrasonography.

Advancements in thoracoscopic surgery have provided us with a deeper anatomical understanding of recurrent laryngeal nerve paralysis (RLNP), which is likely to occur after lymph node dissection. Taking a novel approach to researching the diagnosis of RLNP, we evaluated movement of the vocal cords and arytenoid cartilages using ultrasonography in patients who underwent thoracoscopic esophagectomy. RLNP occurred in six of the 24 patient cohort. The rate of hoarseness and difficulty in discharging sputum was significantly higher in the paralyzed group than in the non-paralyzed group. The diagnostic accuracy of RLNP by ultrasonography had a sensitivity of 83.3% (5/6), a specificity of 88.8% (16/18), a false positive rate of 5.6% (1/18), and a false negative rate of 0% (0/6). Although it is not completely accurate, our findings indicate that ultrasonography is quite effective for diagnosing RLNP, more so in combination with clinical symptoms. Ultrasonography may also be effective for identifying patients who are amenable to laryngoscopy for diagnosing RLNP, or for evaluating the recovery status of nerve paralysis.

Development of In-Office Laryngeal Nerve Conduction Studies: Computed Tomography and Cadaveric Study.

OBJECTIVES/HYPOTHESIS: In-office recurrent laryngeal nerve conduction studies (NCSs) are a technique that can potentially provide information about laryngeal innervation. NCS is essential in the management of other neuropathies including carpal tunnel syndrome and spinal cord injury. We hypothesize that laryngeal NCS may have similar utility in managing patients with vocal fold paralysis, atrophy, and neurodegenerative disease. NCSs are technically challenging because they require transcervical stimulation of the recurrent laryngeal nerve (RLN). This study combines radiographic data with cadaveric dissection to describe the anatomic parameters for optimal RLN stimulation. STUDY DESIGN: Radiographic and Cadaveric Study. METHODS: Fifty computed tomography scans were reviewed to determine the dimensions for ideal needle electrode placement. These values were compared to measurements from 12 fresh human cadaveric neck dissections. Ultrasound imaging was utilized in select cases. The neck was dissected to assess the accuracy of electrode placement. RESULTS: Radiographically, the mean transcervical depth to the RLN was 33.2 mm ± 8.3 mm in males versus 29.4 mm ± 9.4 mm in females. The working space between the lateral trachea and carotid artery was 15.3 mm ± 3.6 mm on the right and 14.1 mm ± 2.9 mm on the left. After placement of stimulating electrodes into the cadaveric neck, the electrode tips were consistently within 8 mm of the RLN. Ultrasound guidance improved placement accuracy of the stimulating electrode. CONCLUSIONS: Laryngeal NCSs can provide detailed and objective information about laryngeal innervation that could dramatically improve the management of various neuropathies. In-office NCSs require technical precision, and this study describes anatomic factors that may affect the feasibility of performing this technique. LEVEL OF EVIDENCE: NA Laryngoscope, 131:1566-1569, 2021.

Endobronchial Ultrasound Improves Evaluation of Recurrent Laryngeal Nerve Lymph Nodes in Esophageal Squamous Cell Carcinoma Patients.

BACKGROUND: The bilateral recurrent laryngeal nerve (RLN) lymph nodes are the most common metastatic site for esophageal squamous cell carcinoma (ESCC); however, the RLNs are susceptible to injury during dissection. Clinically, there is an urgent need to determine an effective diagnostic method for RLN nodes to help achieve selective nodal dissection and avoid potential serious complications by performing more conservative surgery for those with nonmetastatic nodes. Here, we innovatively applied endobronchial ultrasonography (EBUS) and investigated its diagnostic performance for preoperative evaluation of RLN nodes in ESCC patients. PATIENTS AND METHODS: All 81 enrolled ESCC patients underwent preoperative EBUS and CT examinations. The ability of EBUS and CT to detect RLN node metastasis was evaluated based on the resulting sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: The diagnostic performance of EBUS was superior to that of CT; in particular, EBUS of the left RLN (L-RLN) nodes presented the best sensitivity, specificity, PPV, NPV, and accuracy compared with EBUS evaluations of the right RLN (R-RLN) nodes, CT of the L-RLN and R-RLN nodes. Moreover, EBUS combined with CT increased the NPV relative to that of EBUS or CT alone, promoting the ability to identify true-negative RLN nodes. In particular, the NPVs of the combined modality were 100% for both the L- and R-RLN nodes in early-T-stage (T1-T2) ESCC. CONCLUSIONS: EBUS is an efficient tool for RLN node evaluation, and the combination with CT may provide better guidance for selective RLN node dissection in ESCC patients.

Radiology in Neurolaryngology.

The role of imaging in assessment of neurolaryngology will predominantly involve the assessment of pathology along that of laryngeal nerve pathways. The anatomical pathways of the vagus and laryngeal nerves are well described in standard anatomical textbooks and will not be detailed here. Whilst there are 3 principle laryngeal nerves/branches, the recurrent laryngeal nerve will clearly constitute the mainstay of imaging input. This chapter will elaborate on the pathology encountered at the various levels and the imaging characteristics of these disorders. Prior to this, there will be a summary of normal laryngeal imaging appearances to familiarise with the characteristics of radiological anatomy.

Clinical and sonographic features for the preoperative prediction of lymph nodes posterior to the right recurrent laryngeal nerve metastasis in patients with papillary thyroid carcinoma.

OBJECTIVE: To evaluate clinical and sonographic features predictive of lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) metastasis in patients diagnosed with papillary thyroid carcinoma (PTC). METHODS: We retrospectively reviewed the clinical records and ultrasound (US) images of 479 consecutive PTC patients who received total thyroidectomy or right lobectomy with central neck dissection (CND) between October 2017 and October 2019. Univariate and multivariate analyses were performed to identify clinical and sonographic features associated with LN-prRLN metastasis. Receiver operating characteristic (ROC) analysis was applied to evaluate the efficacy of clinical and sonographic features in the preoperative prediction of LN-prRLN metastasis. RESULTS: Overall, 127 (26.5%) patients had LN-prRLN metastasis. Multivariate logistic regression analysis showed that age < 45 years (p = 0.005; OR 2.155; 95% CI 1.262-3.683), male sex (p = 0.043; OR 1.657; 95% CI 1.016-2.704), tumor diameter > 1 cm (p = 0.042; OR 1.702; 95% CI 1.019-2.842), microcalcifications (p = 0.022; OR 1.980; 95% CI 1.104-3.551), and US-detected lateral compartment lymph node (LLN) metastasis (p = 0.001; OR 2.578; 95% CI 1.500-4.430) were independent risk factors for LN-prRLN metastasis. ROC analysis revealed that the multivariate logistic regression model had good accuracy in predicting LN-prRLN metastasis, with an area under the ROC curve of 0.758. CONCLUSIONS: Age less than 45 years, male sex, tumor diameter larger than 1 cm, microcalcifications, and US-detected LLN metastasis may preoperatively predict LN-prRLN metastasis.

Paraganglioma of the recurrent laryngeal nerve.

Paragangliomas of the head and neck are rare, and most frequently benign, slow growing, and nonsecretory. The most frequent locations these tumors arise in the head and neck include the carotid body, jugular bulb, vagus nerve, tympanic branch of the glossopharyngeal nerve, and sympathetic chain. Here we present, to our knowledge, the second reported case of paraganglioma of the recurrent laryngeal nerve. This case is unique given the patient presentation due to ipsilateral vocal fold paralysis, which has not previously been reported, lack of previous surgery, and demonstration of loss of succinate dehydrogenase iron-sulfur subunit B expression. Laryngoscope, 2019.

Parapharyngeal abscess and vocal cord palsy caused by minor salivary gland sialadenitis: an atypical presentation treated using an endoscopic surgical approach.

Parapharyngeal infections carry a significant risk of extensive suppuration and airway compromise. We report the case of a patient presenting with a right paranasopharyngeal abscess, featuring atypical symptoms that made diagnosis particularly challenging. Complications included evidence of right vocal cord paralysis, likely secondary to involvement of the vagus nerve. Notably, this paralysis occurred in isolation, without involvement of cranial nerves IX or XI, which would be expected from jugular foramen encroachment. Imaging demonstrated the presence of a collection extending towards the skull base, which was drained using a transnasal endoscopic approach, avoiding the use of external incisions. Tissue biopsies from the abscess wall suggest that the underlying aetiology was minor salivary gland sialadenitis, which has not been previously reported in the literature.

Anatomical variation in the right non-recurrent laryngeal nerve reported from studies using pre-operative arterial imaging.

The right non-recurrent (inferior) laryngeal nerve (NRLN) is a rare anatomical variant associated with an arterial anomaly, the aberrant right subclavian artery (ARSA), that is detectable by pre-operative imaging (POI) using computed tomography and/or ultrasound. Most surgical studies have utilized two major types, NRLNs arising near the upper pole of the thyroid gland (type 1), vs. at a lower level (type 2) but with two subtypes defined by relationships to the inferior thyroid artery (ITA). This review found 8 English language surgical studies using POI that reported at least 1 NRLN and had anatomical information; of the 88 right NRLNs, 69.3% were classified as type 2 and 30.7% as type 1. Meta-analysis yielded a weighted proportion of 74.0% for type 2, but with substantial heterogeneity. For a subgroup of 5 POI studies with information on subtypes, 22 (59.5%) of 37 type 2 nerves were type 2a (i.e., running at or above the ITA). Similarly, a separate review of large surgical series without POI found that 60.4% of all 91 type 2 NRLNs were type 2a. The study findings should be relevant to the increasing numbers of anterior neck surgeries including bilateral thyroidectomies. A need was identified for studies on inter-observer reliability (agreement) among surgeons on NRLN types, and on injury rates (and related symptoms) by the type of NRLN.

The Feasibility of a Prototype Thyroidoscope for Gasless Transoral Endoscopic Thyroidectomy: A Preclinical Cadaver Study.

Objective: This study aimed to evaluate the feasibility of the gasless transoral endoscopic thyroidectomy vestibular approach (TOETVA) using the Thyroidoscope, developed to maintain the surgical working space without CO2 insufflation. Materials and Methods: To prevent a potentially fatal CO2-related complication, we developed a retractable device, named the Thyroidoscope, which could maintain the surgical working space without CO2 insufflation. We conducted a preclinical cadaver study to evaluate its use in gasless TOETVA. Results: The Thyroidoscope provided a secure surgical field and stable image on the screen. We could successfully identify the recurrent laryngeal nerve, parathyroid gland, and other critical structures without inadvertent injury due to insertion of the Thyroidoscope. Conclusions: The Thyroidoscope provides sufficient working space to perform transoral thyroid surgery without the need for CO2 insufflation. Gasless TOETVA with the Thyroidoscope seems to be feasible and safe.

Diagnostic value of intraoperative ultrasonography in assessing thoracic recurrent laryngeal nerve lymph nodes in patients with esophageal cancer.

BACKGROUD: The incidence of recurrent laryngeal nerve (RLN) injury has increased due to RLN lymph node dissection. The aim of this study was to evaluate the ability of intraoperative ultrasonography (IU) to detect RLN nodal metastases in esophageal cancer patients. METHODS: Sixty patients with esophageal cancer underwent IU, computed tomography (CT), and endoscopic ultrasonography (EUS) to assess for RLN nodal metastasis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were compared. RESULTS: The sensitivities of IU, CT, and EUS in diagnosing right RLN nodal metastases were 71.4, 14.3, and 30.0%, respectively, and a significant difference among these three examinations was observed (χ2 = 10.077, P = .006). The specificities of IU, CT, and EUS for diagnosing right RLN nodal metastasis were 67.4, 97.8, and 95.0%, respectively, and a significant difference was observed (χ2 = 21.725, P < .001). No significant differences in either PPV or NPV were observed when diagnosing right RLN nodal metastases. For diagnosis of left RLN lymph nodal metastases, the sensitivities of IU, CT, and EUS were 91.7, 16.7, and 40.0% respectively. There was a significant difference among these diagnostic sensitivities (χ2 = 14.067, P = .001). The specificities of IU, CT, and EUS for diagnosis of left RLN nodal metastases were 79.2, 100, and 82.5%, respectively and a significant difference was observed (χ2 = 10.819, P = .004). No significant differences were observed in PPV or NPV for these examinations when diagnosing left RLN nodal metastases. CONCLUSION: Intraoperative ultrasonography showed superior sensitivity compared with preoperative CT or EUS in detecting RLN lymph node metastasis in patients with thoracic esophageal cancer.