Electrophysiologic recurrent laryngeal nerve monitoring during thyroid and parathyroid surgery: international standards guideline statement

Feasibility of Cricothyroid Muscle Needle Electrode for Monitored Thyroidectomy

OBJECTIVES

Preservation of the recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN) is essential to maintain voice function after thyroidectomy. Intraoperative neuromonitoring (IONM) assists in nerve preservation. This study compares three IONM modalities, endotracheal surface electrode (ETSE), thyroid cartilage needle electrodes (TCNE), and cricothyroid muscle needle electrode (CTNE), in their monitoring of laryngeal muscle electromyographic (EMG) amplitude.

METHODS

An observational prospective cohort study included 29 patients (21F:8M) undergoing thyroidectomy for Bethesda III-VI nodules or benign nodules >4 cm. EMG amplitudes were recorded via ETSE, TCNE, and CTNE following stimulation of the EBSLN, RLN, and vagus nerve (VN).

RESULTS

A total of 105 nerves at risk were assessed, including 35 EBSLNs, 35 VNs, and 35 RLNs. The recorded amplitudes at S1 for the ETSE, TCNE, and CTNE were 45.6 ± 60.7 μV, 403.7 ± 865.4 μV, and 3049.4 ± 2749.8 μV. The CTNE demonstrate significantly higher S1 amplitudes and positive signal rates compared with both the TCNE and ETSE (p < 0.001). For V1, the recorded amplitudes for the ETSE, TCNE, and CTNE were 453.7 ± 406.7 μV, 1363.9 ± 1063.6 μV, and 700 ± 375.1 μV. For R1, the recorded amplitudes for the ETSE, TCNE, and CTNE were 567.1 ± 556 μV, 1544.6 ± 1269.6 μV, and 720.4 ± 363.1 μV. With a threshold of 100 μV to determine positive signal, CTNE detected all EBSLN, VN, and RLN signals, whereas TC missed 13 cases (37.1%) of EBSLN.

CONCLUSION

The CTNE showed a higher positive signal rate than ETSE and TCNE in detection of EBSLN, whereas it showed similar performance with TCNE in detection of VN and RLN. CTNE is a viable option for IONM during thyroidectomy.

LEVEL OF EVIDENCE

2 Laryngoscope, 135:1843-1849, 2025.

Role of the Laryngeal Adductor Reflex in the Prevention of Thermal Injury to the Recurrent Laryngeal Nerve in Thyroid Surgery: A Case Report

BACKGROUND

Intraoperative neuromonitoring (IONM) of the recurrent laryngeal nerve (RLN) aims to detect and prevent iatrogenic damage during thyroid surgery. Mechanisms of injury include traction, heat damage, and nerve transection. Continuous IONM (C-IONM) techniques detect impending damage due to traction and heat related when they are still reversible.

METHODS

We present a 73-year-old woman who underwent a total thyroidectomy due to a goiter. The IONM included intermittent IONM (I-IONM) in combination with C-IONM using the laryngeal adductor reflex (LAR). The intraoperative neurophysiological signals recorded were correlated with the surgical maneuver and the postoperative evaluation.

RESULTS

During surgery, a significant decrease in left LAR amplitude was observed, coinciding with the use of the harmonic. After some corrective maneuvers, the intraoperative signals recovered, and the postoperative examination showed adequate VF function.

CONCLUSIONS

C-IONM of the RLN using the LAR can be a valuable tool for detecting and preventing thermal spread injury during thyroid surgery.

Intraoperative nerve monitoring in thyroid and parathyroid surgery: a decade of Italian practice

Intraoperative nerve monitoring (IONM) has been recognized as a useful adjunct into the field of thyroid and parathyroid surgery, aiding in the accurate identification and preservation of the recurrent laryngeal nerve (RLN), consequently reducing the probability of nerve injury and promoting surgical safety. This investigation seeks to amplify the findings of a similar nationwide survey performed in 2014 by offering an updated assessment of IONM practices among Italian surgical institutions, reflecting a decade of advancements and transformations in clinical approaches. A comprehensive nationwide survey was implemented targeting Italian endocrine surgeons to assess the prevalence, utilization patterns, attitudes and perceptions surrounding IONM in the context of thyroid and parathyroid surgical procedures. Structured questionnaires were administered to seventy endocrine surgery centers, and the resulting data were evaluated employing both quantitative and qualitative analysis methods. The survey disclosed that 67.14% of the participants confirmed the routine deployment of IONM across all cervical surgical procedures, particularly in high-risk contexts. Relative to the findings from 2014, a marked rise in the implementation of IONM has been recorded; however, variability persists, especially between continuous and intermittent monitoring strategies. Surgeons recognized improved surgical safety, decreased complication frequencies, and educational advantages as significant key drivers for the incorporation of IONM. Nonetheless, issues, such as false-positive and false-negative results, along with the lack of standardized protocols, remain barriers to its uniform application. During the past ten years, IONM has been thoroughly adopted by Italian endocrine surgeons as a result of its critical contribution to the improvement of surgical outcomes and the provision of educational resources. However, the results highlight the imperative for further standardization of protocols, the advancement of training programs, and the resolution of reimbursement obstacles to ensure equitable and consistent application of IONM across Italian centers, ultimately optimizing patient care.

The necessity of prophylactic central lymph node dissection in clinically n0 papillary thyroid carcinoma: perspective from the endemic region

BACKGROUND

Prophylactic central lymph node dissection (pCND) in papillary thyroid carcinoma (PTC) is still a matter of debate. Therefore, we aimed to identify the factors affecting central lymph node metastasis (CLNM) in patients with clinically node-negative (cN0) PTC.

METHODS

This retrospective study included 248 patients with cN0 PTC who underwent total thyroidectomy (TT) or TT + pCND. Clinicopathological associations among CLNM, complication rates and the effect of pCND on staging were assessed. Risk factors (RFs) and the pattern of lymph node metastasis (LNM) in PTC patients were studied via multivariate analysis.

RESULTS

A total of 216 patients underwent pCND, and 58.8% (127/216) had positive CLNM. Male patients, aged < 41 years, and those with lymphatic invasion were identified as RFs for CLNM, with odds ratios of 2.59, 2.26, and 4.09, respectively. Among the 216 patients, 65 (30%) had transient hypoparathyroidism (HPT), and 20 (9.3%) had permanent HPT. Transient recurrent laryngeal nerve (RLN) palsy occurred in 15 (6.9%) patients, and permanent RLN palsy occurred in 3 (1.4%) patients. Over 55 years of age, 46.7% of patients were upstaged according to the American Joint Committee on Cancer (AJCC) TNM staging system, and 14.2% (n = 18) of the 127 patients with CLNM were upgraded according to the American Thyroid Association (ATA) risk stratification system (RSS).

CONCLUSION

Taken together, in terms of the high incidence rate of CLNM in cN0 PTC patients; We believe that routine pCND, which can be performed with low morbidity rates, is optimal for cN0 PTC patients during their first treatment, especially for those with RFs for CLNM.

CLINICAL TRIALS NUMBER

NCT05873283.

Neuromuscular Blockade Antagonism for Thyroid Surgery During Intraoperative Neural Monitoring-An Anesthesia Perspective

Background and Objectives: Thyroid surgery with intraoperative neural monitoring (IONM) of the recurrent laryngeal nerve (RLN) requires precise anesthetic management. This narrative review compares non-selective (neostigmine) and selective (sugammadex) reversal agents for neuromuscular blockade (NMB), discussing their mechanisms of action and the challenges of achieving optimal NMB reversal without compromising surgical conditions or IONM quality. Materials and Methods: A literature search was conducted using PubMed, MEDLINE, and Google Scholar for studies published up to November 2023. Relevant case studies, clinical trials, systematic reviews, and guidelines focusing on NMB reversal in thyroid surgery with IONM were included, prioritizing investigations involving sugammadex and neostigmine. Results: Clinical evidence indicates that sugammadex (0.5-1 mg/kg) provides the rapid and reliable return of neuromuscular function, benefiting electromyography (EMG) signal quality preservation. However, overshooting the reversal can precipitate patient movement, compromising surgical precision. Neostigmine (0.03-0.04 mg/kg), while less selective, remains a cost-effective alternative, with recent studies suggesting adequate support for IONM signal integrity when carefully dosed and timed. Conclusions: This review underscores the need for balanced NMB reversal strategies tailored to intraoperative monitoring requirements in thyroidectomy. Further randomized trials and large-scale studies are needed to refine and standardize NMB reversal strategies in thyroid surgery with IONM.

Laryngeal Surgery as It Pertains to the Thoracic Surgeon

A surgeon managing complex airway disease benefits from knowledge of laryngeal physiology and pathology. The Larynx provides phonation and protection for the lower airway via closure and cough reflex. Disruption of these functions or development of paralysis or stenosis can lead to respiratory failure. Management includes a variety of endoscopic and open management techniques. Understanding of laryngeal physiology can also limit laryngeal functional impairment through careful preservation of motor nerves and early recognition of injuries.

Vocal Outcome Following Thyroidectomy for Differentiated Thyroid Carcinoma

Background: Voice alteration is a recognized complication of thyroid surgery, impacting the quality of life and communication for affected individuals. In this prospective observational study, the Acoustic Voice Quality Index (AVQI) was employed to assess vocal outcomes after thyroidectomy. Method: Between February 2018 and August 2022, 224 patients underwent Thyroid surgery in our department, of which 74 with differentiated thyroid carcinoma (DTC) were enrolled in accordance with the inclusion criteria. Endoscopic findings and AVQI scores were evaluated before and after surgery (voice analysis was conducted using the Praat software program version 6.0.33). Results: Vocal fold impairment was present in 6.76% of patients after surgery (T1), with full recovery within 3 months. During preadmission evaluation, an AVQI score > 2.35 indicating hoarseness was present in 37 patients (despite normal vocal cord motility). Of these, 25 (67.57%), 26 (70.27%), and 24 (17.76%) maintained this trend at T1, T2, and T3, respectively. No significant variation in mean AVQI values was observed based on gender, age, and central neck dissection. Conclusion: AVQI values did not show significant variations comparing pre- and postoperative values. Thyroid surgery for DTC performed by experienced surgeons does not seem to impact significantly on patients' voice quality.

Diagnostic accuracy of intraoperative pelvic autonomic nerve monitoring during rectal surgery: a systematic review

PURPOSE

Anorectal and urogenital dysfunctions are common after rectal surgery and have a significant impact on quality of life. Intraoperative pelvic autonomic nerve monitoring (pIONM) has been proposed as a tool to identify patients at risk of these functional sequelae. This systematic review aims to evaluate the diagnostic accuracy of pIONM in detecting anorectal and urogenital dysfunction following rectal surgery.

METHODS

A systematic review of articles published since 1990 was conducted using MEDLINE, Embase, CINAHL, Google Scholar, Scopus, and Web of Science. Studies describing pIONM for rectal surgery and reporting anorectal or urogenital functional outcomes were included. The risk of bias was assessed using the QUADS-2 tool. The diagnostic accuracy of pIONM was established with pooled sensitivity and specificity alongside summary receiver-operating characteristic curves.

RESULTS

Twenty studies including 686 patients undergoing pIONM were identified, with seven of these studies including a control group. There was heterogeneity in the pIONM technique and reported outcome measures used. Results from five studies indicate pIONM may be able to predict postoperative anorectal (sensitivity 1.00 [95% CI 0.03-1.00], specificity 0.98 [0.91-0.99]) and urinary (sensitivity 1.00 [95% CI 0.03-1.00], specificity 0.99 [0.92-0.99]) dysfunction.

CONCLUSIONS

This review identifies the diagnostic accuracy of pIONM in detecting postoperative anorectal and urogenital dysfunction following rectal surgery. Further research is necessary before pIONM can be routinely used in clinical practice.

PROSPERO REGISTRATION DETAILS

CRD42022313934.

Implementation of a Standardized Protocol for Recurrent Laryngeal Nerve Monitoring Reduces False Negative Results During Neck Surgery: A Quality Control Case Study

Recurrent laryngeal nerve (RLN) injury during neck surgery can cause significant morbidity related to vocal cord (VC) dysfunction. VC electromyography (EMG) is used to aid in the identification of the RLN and can reduce the probability of inadvertent surgical injury. Errors in the placement of specialized EMG endotracheal tubes (ETT) can result in unreliable signals, false-negative responses, or no response when stimulating the RLN. We describe a novel educational protocol developed to optimize uniformity in the placement of ETTs to improve the reliability of RLN monitoring. An intraoperative neuromonitoring database was queried for all neck surgeries requiring RLN monitoring. Data points extracted for all cases requiring EMG monitoring for neck procedures. Free running and stimulated EMG were monitored and continuously recorded by a certified technologist. Alerts were compared between 2013-14 and 2015-18 using a two-sample test of proportions. Significant reductions in alerts were demonstrated after protocol implementation (7.5% pre-implementation to 2.1% post). Alerts were compared between 2013-14 (overall alert rate of 1.8%, pre-implementation period) and 2015-18 (overall alert rate of 2.8%, post-implementation period). Protocolization for placement of EMG-ETT improved accuracy in EMG monitoring. In the follow-up cohort of 1,080 patients, use of this protocol continued to reduce the rate of alerts related to ETT malposition, confirming the sustainability of this intervention through routine education. The risk of nerve injury is reduced when the rate of alerts is minimized. Scheduled or continuous protocol education of anesthesia personnel should continue to ensure compliance with protocol.

State of the art of neuromonitoring in thyroid surgery

Thyroidectomy is a common procedure in endocrine surgery, frequently performed to treat benign and malignant thyroid conditions. Recurrent laryngeal nerve (RLN) injury, a major complication, underscores the necessity for meticulous nerve dissection during surgery. Intraoperative neuromonitoring (IONM) has emerged as a valuable adjunct to visual identification in RLN preservation. This review synthesizes current literature on IONM in thyroid surgery, emphasizing its role in enhancing RLN integrity assessment and reducing surgical complications such as vocal cord paralysis. IONM techniques include intermittent and continuous monitoring, each offering distinct benefits in nerve function evaluation. While debate persists regarding IONM's efficacy in mitigating unilateral RLN injuries, protocols integrating IONM data have significantly reduced the incidence of bilateral RLN injury, exemplifying advancements in surgical safety. Challenges remain, including variability in study outcomes and the optimal timing of IONM application.

Influence of Anesthesiology Protocol on the Quality of Intraoperative Nerve Monitoring During Thyroid Surgery, One-Year Single Center Experience

BACKGROUND/OBJECTIVES

Anesthesia plays a very important role in the successful management of intraoperative neuromonitoring (IONM). The aim of our study was to investigate the impact of anesthesia induction and maintenance on the quality of signals during surgeries on the thyroid and parathyroid glands using neuromonitoring.

METHODS

The study included 72 patients who underwent surgery with IONM for one year. All the patients were intubated using a Glidescope videolaryngoscope with a hyperangulated blade. Two different approaches were used to facilitate intubation: succinylcholine-1 mg/kg and rocuronium bromide-0.3 mg/kg. For anesthesia maintenance, total intravenous anesthesia (TIVA) or combined anesthesia was used. Patients' body movements during operations, as well as electromyography signals from the vagus and recurrent laryngeal nerves before resection, were recorded as V1 and R1.

RESULTS

Intraoperative unwanted movements were recorded in 25% of patients. Undesired movements were more frequently recorded in the TIVA group compared to the combined anesthesia group (p < 0.001) as well as in patients who received succinylcholine compared to patients who received rocuronium bromide (p = 0.028). Type of anesthesia maintenance as well as type of muscle relaxant did not affect the quality of recorded nerve signals. (p = 0.169 and p = 0.894, respectively).

CONCLUSIONS

The type of muscle relaxant used significantly affects the occurrence of undesirable movements during thyroid surgery with IONM, while the type of anesthesia maintenance did not influence either the quality of the obtained signal or the occurrence of undesirable movements.

Intraoperative Facial Nerve Monitoring during Parotidectomy: The Current Practices and Patterns of the Korean Society of Head and Neck Surgery (KSHNS)

Objectives: This study aimed to evaluate the current practices and trends of intraoperative facial nerve (FN) monitoring (IOFNM) during parotidectomy. Methods: A questionnaire containing 33 questions collecting information on the usage, indications, settings, techniques, loss of signal (LOS) management, anesthesiologist cooperation, and perception of usefulness of IOFNM was distributed among 348 members of the Korean Society of Head and Neck Surgery (KSHNS) via a dedicated website. Results: The response rate was approximately 25.6%, and 97% of the respondents reported using IOFNM selectively or routinely during parotidectomy. IOFNM usage decreased as the surgeon's level of experience increased (p = 0.089), from 100% in those with less than 5 years of experience to 75% in those with 20 or more years. Approximately 95% of respondents reported that the initial event threshold for electromyography activity used was 50-149 μV. Moreover, 52.4% of respondents performed neural mapping of the FN before visual identification. Initial management of LOS in visually intact FNs included checking the IOFNM system (75.3%), confirmation of muscle relaxant dosage (75.3%), and facial twitch identification (58.8%). Further management included proceeding with surgery regardless of persistent LOS (81.2%) and steroid administration sometimes or all of the time (72.9%). Overall, 98.8% of respondents found IOFNM beneficial for safe execution of parotidectomy. Conclusions: The majority of KSHNS surgeons used IOFNM during parotidectomy, although the clinical implementation of the procedure and LOS management varied between practitioners. This could be attributed to the lack of standardized protocols for IOFNM, emphasizing the need for the development of evidence-based consensus guidelines for all institutions.

A unique complication of thyroidectomy for Hashimoto's thyroiditis: central retinal artery thrombosis

BACKGROUND

Central retinal artery occlusion (CRAO) is a rare ophthalmological emergency and also a unique complication after thyroid surgery.

METHODS

We present the first case of CRAO following thyroid surgery in a patient with Hashimoto's thyroiditis, along with a variety of interventions to overcome this complication.

RESULTS

A 42-year-old female patient suffering from sudden vision loss following total thyroidectomy was diagnosed with CRAO. Hyperbaric oxygen therapy was started within the postoperative first 6 hours.

CONCLUSION

Although it is extremely rare, it should be noted that patients may experience retinal artery occlusion following the thyroid surgery. Immediate evaluation of patients with visual impairment in the early postoperative period, and planning of emergent hyperbaric oxygen therapy for the management are critical.

Is trans-thyroid cartilage monitoring as good as endotracheal tube monitoring during thyroidectomy?

PURPOSE

To evaluate whether trans-thyroid cartilage nerve monitoring for thyroid surgeries is as effective and safe as endotracheal tube monitoring.

METHODS

Fifty-one thyroidectomies (38 hemithyroidectomies and 13 total thyroidectomies, analyzed as two separate hemi-thyroidectomies) were included. Patients undergoing surgery from 6/2020 to 8/2021 were monitored simultaneously with the NIM® Nerve Monitoring System TriVantage™ Electromyography (EMG) endotracheal tube and EMG trans-thyroid cartilage. Electrophysiological responses of 64 vagus and recurrent laryngeal nerves were obtained. Peri-operative evaluation and 12-month post-operative follow-up were conducted to examine nerve function. Wilcoxon signed-rank and Spearman coefficient tests were used to determine whether there were differences between the methods.

RESULTS

The average initial amplitude measured with the trans-thyroid cartilage method was higher in the recurrent laryngeal and vagus nerves (p = 0.002, p = 0.003, respectively). The mean difference in EMG amplitude from start to end of surgery for 10 damaged nerves (7 temporary and 3 permanent) differed from intact nerves in both methods and nerves (p < 0.05 for all). Among intact recurrent laryngeal nerves, 20.4% had 20-80% decrease in amplitude in endotracheal tube electrodes and 16.7% in trans-thyroid cartilage electrodes (p = 0.92). All cases with stable EMG signals or with increased EMG amplitude (with both types of electrodes and with both nerves) had normal post-operative vocal function. No significant difference was found between the two methods when measuring the vagus and recurrent laryngeal nerves. No complications occurred when using trans-thyroid cartilage electrodes.

CONCLUSIONS

Trans-thyroid cartilage nerve monitoring for thyroid surgeries is as effective and safe as the current standard monitoring using an endotracheal tube. During thyroid surgery, patients are monitored to avoid damaging nerves near the vocal cords. This study compared monitoring through a throat tube with the easier method of monitoring outside of the throat to see if it is as effective and safe. No major difference was found between the two methods and there were no problems.

[Modern thyroid surgery : Efficient and safe thyroidectomy technique]

After decades of bilateral "subtotal" and later "total" thyroidectomy, the extent of resection is now determined individually depending on the dominant thyroid condition. The leading indication by far in the study, documentation and quality center (StuDoQ) register of the Surgical Working Group Endocrinology (CAEK) is currently the suspicion of malignancy, which is followed by benign symptomatic nodular goiter, functional disorders and confirmed malignancy. The decision for an intervention as well as the extent of resection must be rigorously established. Aids for intraoperative nerve monitoring, vessel-sealing and parathyroid autofluorescence increase the safety of thyroid resections but also the complexity. The surgical technique of lobectomy using modern devices for vessel sealing is an intricate process in which the positioning, access to the neck and a modified sequence of dissection steps are equally important. While the usefulness of neuromonitoring is nowadays no longer in doubt, this is not yet so clear for other technologies. Above all, however, modern thyroid surgery is characterized by the knowledge of one's own results and a clear positioning to follow-ups. The selection of any surgical aid should be based on this knowledge.

Thyroid cartilage needle vs. endotracheal tube electrodes in EBSLN monitoring during thyroidectomy

During thyroidectomy, both needle electrodes (NE) and endotracheal tube electrodes (ETE) can be used. Incomplete contact of the endotracheal tube electrode with the vocal cords, endotracheal tube electrode may hinder an optimal outcome and even result in an inability to obtain an electromyography wave while neuromonitoring the external branch of the superior laryngeal nerve (EBSLN). There is no study that compares NE and ETE for EBSLN monitoring. Therefore, this study compares NE and ETE recordings during EBSLN monitoring. Twenty-six consecutive patients undergoing total thyroidectomy were included in this study. Intraoperative neuromonitoring was performed simultaneously with both NEs and ETEs. Pre-resection (V1, R1, and S1) and post-resection (V2, R2, and S2) amplitudes and latencies were recorded for both types of electrodes. The Mann-Whitney U test was used for statistical analysis. Twenty-one women and five men were included, and 52 nerves at risk were evaluated. The mean amplitudes for right S1 (314 vs. 168 µV, p = 0.009) and right S2 (428 vs. 161 µV, p: 0.001) and for left S1 (346 vs. 229 µV, p: 0.017) and left S2 (413 vs. 229 µV, p: 0.009) were statistically higher for the NE group. All amplitudes obtained using NEs, except on the left for V1, R1, V2, and R2, were statistically higher than those obtained using ETEs. There was no loss of signal or vocal cord palsy in the patients. There were no needle-related complications. EBSLN monitoring using NE is a safe alternative to ETE. With NE, higher amplitudes were obtained. Level of evidence: Level 3.

Electrophysiological monitoring of the nonrecurrent inferior laryngeal nerve and radiological evaluation of concurrent vascular anomalies

Purpose

The objective of this study was to characterize the electrophysiological characteristics of nonrecurrent inferior laryngeal nerves (NRILNs) that were dissected via intraoperative neuromonitoring (IONM) and concomitant vascular anomalies in patients with NRILNs.

Methods

A retrospective analysis was conducted on 7865 patients who underwent thyroidectomy with IONM at three tertiary referral centers. The study included 42 patients in whom an NRILN was detected. IONM data and postoperative vocal cord (VC) examinations were recorded for all patients. The absence of an initial vagal EMG response and/or a short (<3.5 ms) latency period during the initial vagal stimulation or the inability to identify the RLN within the Beahrs triangle was considered highly suspicious for the presence of an NRILN. Postoperative cross-sectional imaging was performed in 36 out of 42 patients to assess any concurrent vascular anomalies.

Results

The prevalence of NRILN was 0.53%. An NRILN was suspected due to EMG findings in 32 (76%) patients and the inability to identify the RLN within the Beahrs triangle in the remaining 10 (24%) patients. The mean right VN latency period was 3.05 ± 0.15 ms. The V1 latency period of the right VN was shorter than 3.5 ms in 39 (93%) and longer than 3.5 ms in 3 (7%) patients. One of these three patients with latency>3.5ms had a large mediastinal goiter. Transient VC paralysis occurred in one (2.4%) patient. Of the 36 patients with postoperative imaging data, 33 (91.4%) had vascular anomalies. All 33 patients had aberrant right subclavian arteries, and 13 (39.4%) also had accompanying additional vascular anomalies.

Conclusion

The NRILN is an anatomical variation that increases the risk of nerve injury. Observation of an absent EMG response and/or a short latency period during the initial vagal stimulation facilitates the detection of an NRILN at an early stage of thyroidectomy in the majority of patients.

Echotexture of recurrent laryngeal nerves: the depiction of recurrent laryngeal nerves at high-frequency ultrasound during radical thyroidectomy

Introduction

To investigate the ultrasound characteristics of recurrent laryngeal nerves (RLNs) during radical surgery for thyroid cancer and to enhance the understanding of RLN ultrasound features.

Methods

From October 2021 to December 2022, a prospective study was conducted involving 24 patients scheduled for bilateral thyroid surgery. Near the conclusion of the surgery, intraoperative ultrasonography of the RLN within the tracheoesophageal groove was performed using a 15-7 MHz transducer. The thickness and width of the RLN were measured during the procedure.

Results

The internal architecture of the RLN was observed to consist of multiple hypoechoic, parallel, but discontinuous linear hyperechoic areas separated by bands. In the normal RLN group, the diameter of the RLN was relatively consistent, with thickness ranging from 2.20 to 2.71 mm (mean: 2.48 ± 0.14 mm) and width from 1.25 to 1.70 mm (mean: 1.45 ± 0.11 mm). Both weight and the body mass index (BMI) showed a statistically significant correlation with RLN thickness (Weight: r=0.544, P=0.001; BMI: r=0.605, P=0.001). The BMI also showed a statistically significant correlation with the RLN width (r=0.377, P=0.033). In the RLN invasion group, the width of invaded RLNs ranged from 1.9 to 2.3 mm (mean: 2.10 ± 0.11 mm), while the width of non-invaded RLNs ranged from 2.6 to 3.2 mm (mean: 2.93 ± 0.20 mm).

Conclusions

Ultrasound effectively reveals the structural features of the RLN and enhances sonographers' understanding of RLN characteristics.

Long-Term Outcomes of Recurrent Laryngeal Nerve Repair/Reconstruction in Oncological Settings

Vocal cord paralysis results from involvement of the recurrent laryngeal nerve (RLN), either before the surgery or following excision. Coaptation of the resected edges utilising microsurgical techniques is the most promising therapeutic strategy available for RLN excision. The RLN can be repaired by direct epineural coaptation or using nerve grafts adhering to recommended microsurgical techniques. This article aims to convey our experience with RLN resections/injuries and their subsequent effects. We assessed the RLN repairs that our institute had completed from April 2018 to September 2023(5 years and 5 months) including follow-up of minimum 1 year. The Functional Oral Intake Scale (FOSI) was applied to assess dysphagia, aspiration risk, and glottic gap by laryngoscopy, and GRBAS (Grade, Roughness, Breathiness, Asthenia, Strain) comprised the basis for the assessment of voice quality by speech specialists. Surgical technique included using 9-0 Ethilon either for primary repair or for repair with a nerve graft. Ten patients were included in the study; six (60%) of them were male with the median age of 32 years. At 12-month follow-up, only 10% (n = 1) was found to have dysphagia. Only 10% (n = 1) had a mild harsh voice. This same patient was the only patient to show a minimal remnant glottic gap. Ten percent (n = 1) patient showed B/l cord mobility at 12 months, while 30% (n = 3) showed flickering movements of the affected vocal cord. In all the patients, the opposite vocal cord was found to be compensating. Thus, immediate repair of RLN is helpful along with the general physiological adaptation of vocal cords to improve phonation and reduce aspiration and dysphagia risks, thus helping to improve the quality of life. The right procedure should choose from the armoury after careful intraoperative assessment.

Impact of Intermittent Intraoperative Neuromonitoring (IONM) on the Learning Curve for Total Thyroidectomy by Residents in General Surgery

INTRODUCTION

Recurrent laryngeal nerve (RNL) identification constitutes the standard in thyroidectomy. Intraoperative nerve monitoring (IONM) has been introduced as a complementary tool for RLN functionality evaluation. The aim of this study is to establish how routine use of IONM can affect the learning curve (LC) in thyroidectomy.

METHODS

Patients undergoing total thyroidectomy performed by surgery residents in their learning curve course in 2 academic hospitals, were divided into 2 groups: Group A, including 150 thyroidectomies performed without IONM by 3 different residents, and Group B, including 150 procedures with routine use of intermittent IONM, by other 3 different residents. LC was measured by comparing operative time (OT), its stabilization during the development of the LC, perioperative complication rate.

RESULTS

As previously demonstrated, the LC was achieved after 30 procedures, in both groups, with no differences due to the use of IONM. Similarly, there were no significant differences among the 2 groups, and between subgroups independently matched, for both OT and complications, even when comparing RLN palsy. Direct nerve visualization and IONM assessment rates were comparable in all groups, and no bilateral RLN palsy (transient or permanent) were reported. No case of interrupted procedure to unilateral lobectomy, due to evidence of RLN injury, was reported.

CONCLUSIONS

The study demonstrates that the use of IONM thyroid surgery, despite requiring a specific training with experienced surgeons, does not particularly affect the learning curve of residents approaching this kind of surgery, and for this reason its routine use should be encouraged even for trainees.

Noninvasive monitoring of the vagus nerve during thyroid surgery using cutaneous adhesive and needle electrodes: What is the optimal configuration?

OBJECTIVE

Endotracheal tube (ETT) surface electrodes are used to monitor the vagus nerve (VN), recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve (EBSLN) during thyroid and parathyroid surgery. Alternative nerve monitoring methods are desirable when intubation under general anesthesia is not desirable or possible. In this pilot study, we compared the performance of standard ETT electrodes to four different noninvasive cutaneous recording electrode types (two adhesive electrodes and two needle electrodes) in three different orientations.

METHODS

The VN was stimulated directly during thyroid and parathyroid surgery using a Prass stimulator probe. Electromyographic (EMG) responses for each patient were recorded using an ETT plus one of the following four cutaneous electrode types: large-foot adhesive, small-foot adhesive, long-needle and short-needle. Each of the four electrode types was placed in three orientations: (1) bilateral, (2) ipsilateral mediolateral, and (3) ipsilateral craniocaudal.

RESULTS

Four surgical cases were utilized for data collection with the repetitive measures obtained in each subject. Bilateral electrode orientation was superior to ipsilateral craniocaudal and ipsilateral mediolateral orientations. Regardless of electrodes type, all amplitudes in the bilateral orientation were >100 μV. When placed bilaterally, the small-foot adhesive and the long-needle electrodes obtained the highest EMG amplitudes as a percentage of ETT amplitudes.

CONCLUSION

Cutaneous electrodes could potentially be used to monitor the VN during thyroid and parathyroid procedures. Different electrode types vary in their ability to record amplitudes and latencies. Bilateral orientation improves EMG responses in all electrode types. Additional validation of cutaneous electrodes as an alternative noninvasive method to monitor the VN is needed.

The impact of intraoperative neural monitoring during papillary thyroid cancer surgery on completeness of thyroidectomy and thyroglobulin response: a propensity-score matched study

BACKGROUND

Intraoperative neural monitoring (IONM) has been utilized for a variety of thyroid pathologies, including papillary thyroid carcinoma (PTC). Remnant thyroid tissue following total thyroidectomy (TT) in patients with PTC is associated with increased recurrence. The aim of this study is to investigate whether the use of IONM in PTC surgery has an impact on the completeness of thyroidectomy.

METHODS

Retrospectively, patients with preoperative diagnosis of PTC, who underwent TT in a tertiary center were reviewed. They were grouped based on the IONM usage, and 1:1 propensity-score match was performed. Primary outcome was the completeness of thyroidectomy, determined by measuring postoperative stimulated thyroglobulin levels (sTg).

RESULTS

Among 274 clinically node-negative PTC patients who underwent TT and ipsilateral prophylactic central lymph-node dissection, a total of 170 patients (85:85) were matched. Postoperative sTg levels were significantly lower in the IONM group (1 ng/dL vs. 0.4 ng/dL; p < 0.01) with higher percentage of the patients with sTg levels <1 ng/ml (50.6% vs. 69.4%; p = 0.01). More patients in the no-IONM group received RAI ablation with significantly higher doses (mean mci: 120 vs. 102; p = 0.02).

CONCLUSION

The use of IONM during thyroidectomy provides improvement in the completeness of thyroidectomy and reduction in postoperative sTg levels which can be used as a guide by clinicians to avoid RAI ablation in selected PTC patients and to adjust low ablative doses in patients who are scheduled for remnant ablation.

Patterns and indications of intraoperative nerve monitoring usage during thyroidectomy and parathyroidectomy in Spain: results of a national survey of endocrine surgeons

We investigated the use patterns and indications of intraoperative neural monitoring (IONM) among endocrine surgeons in Spain. We sent an anonymous web-based survey to endocrine surgeons' members of the Spanish Association of Surgery by email. We analysed 79/ 269 surveys. Respondents had a median age of 52 years and 13 years of surgical experience. Only 32% of respondents performed routinely preoperative laryngoscopy in all thyroidectomies and 19% in all parathyroidectomies. Seventy-five percent of respondents used the intermittent-IONM, and 9.7% used the continuous-IONM. All respondents identified recurrent laryngeal nerve during surgery, and 40% of surgeons routinely identified external branch superior laryngeal nerve (EBSLN) during thyroidectomy. Seventy-eight percent of respondents used IONM always for all thyroidectomies. Only 11% stimulated EBSLN in all cases. Forty-nine percent used IONM always for all parathyroidectomies. The most frequent reasons for not using IONM were the unavailability of IONM, the high cost, and the lack of adding value to their clinical practice. Almost 10% declared not having IONM. The IONM is a reality in Spain, especially the intermittent mode. Its use is superior in thyroid surgery than in parathyroid. Its standardized use is not yet fully established, and routine adherence to standardized guidelines should increase.

Frequency of side effects experienced in two different NIM-EMG tubes used in thyroid and parathyroid surgery; a prospective observational study

BACKGROUND

In this study, we observed the frequency of side effects encountered when the neural integrity monitor electromyogram endotracheal tube (NIM-EMG-ETT) was used in thyroidectomy and parathyroidectomy surgeries.

METHODS

After obtaining hospital ethics committee approval, 239 cases affiliated with the American Society of Anesthesiologists (ASA II-IV) who used NIM EMG tubes in thyroid and parathyroid surgery were included in the prospective observational study. Tube and patient-related complications encountered with two different NIM EMG-ETT (silicone and polyvinyl chloride-PVC) were recorded.

RESULTS

The average age of the patients is 49.50 ± 13.44 years, the average BMI is 28.25 ± 4.91 kg/m2, the median surgery time is 115 (32-475) minutes, 75.7% are women, 97.5% are ASA II. Additional diseases other than thyroid and parathyroid problems were present in 77.3%. Thyroidectomy was performed in 73.2% of the patients. In our study, only 0.8% of patients with transient recurrent laryngeal nerve RLN paralysis were observed in thyroid and parathyroid surgeries performed using NIM-EMG tubes, 3 patient already had nerve involvement in the preoperative period. The most common complication was loss of stimulation response related to tubes and patient-related ventilation failure. There was no difference between the complications of silicone and PVC tubes except for irregular EMG response.

CONCLUSIONS

There was no significant difference in side effects other than irregular EMG response in the two different tubes we used in our study. It was observed that prolonging the surgical time increased the risk of irregular EMG response. It should not be forgotten that no matter which NIM-EMG tube is used, additional risks are encountered during the intubation and extubation process. In order to avoid negative consequences, it is necessary to follow the usage rules recommended by the manufacturer when using NIM-EMG tubes.

The relation of recurrent laryngeal nerve to inferior thyroid artery and extralaryngeal nerve branching may increase the risk of vocal cord paralysis in thyroidectomy

PURPOSE

The anatomical variations of the recurrent laryngeal nerve (RLN) are common during thyroidectomy. We aimed to evaluate the risk of RLN paralysis in case of its anatomical variations, retrospectively.

METHODS

The patients with primary thyroidectomy between January 2016 and December 2019 were enrolled. The effect of age, gender, surgical intervention, neuromonitorisation type, central neck dissection, postoperative diagnosis, neck side, extralaryngeal branching, non-RLN, relation of RLN to inferior thyroid artery (ITA), grade of Zuckerkandl tubercle on vocal cord paralysis (VCP) were investigated.

RESULTS

This study enrolled 1070 neck sides. The extralaryngeal branching rate was 35.5%. 45.9% of RLNs were anterior and 44.5% were posterior to the ITA, and 9.6% were crossing between the branches of the ITA. The rate of total VCP was 4.8% (transient:4.5%, permanent: 0.3%). The rates of total and transient VCP were significantly higher in extralaryngeal branching nerves compared to nonbranching nerves (6.8% vs. 3.6%, p = 0.018; 6.8% vs. 3.2%, p = 0.006, respectively). Total VCP rates were 7.2%, 2.5%, and 2.9% in case of the RLN crossing anterior, posterior and between the branches of ITA, respectively (p = 0.003). The difference was also significant regarding the transient VCP rates (p = 0.004). Anterior crossing pattern increased the total and transient VCP rates 2.8 and 2.9 times, respectively.

CONCLUSION

RLN crossing ITA anteriorly and RLN branching are frequent anatomical variations increasing the risk of VCP in thyroidectomy that cannot be predicted preoperatively. This study is the first one reporting that the relationship between RLN and ITA increased the risk of VCP.

The Effect of Hemithyroidectomy in Papillary Thyroid Carcinoma with an Exclusive Involvement of the Recurrent Laryngeal Nerve: A Retrospective Study with a Propensity Score-Matched Analysis

BACKGROUND

Involvement of the recurrent laryngeal nerve (RLN) in papillary thyroid carcinoma (PTC) is an important prognostic factor and is associated with a higher risk of recurrence. This study aimed to retrospectively analyze the outcomes of patients treated with hemithyroidectomy (HT) in PTC patients with an exclusive RLN invasion who could not tolerate staged surgery, did not wish to undergo another operation, or had other reasons.

METHODS

A retrospective review was conducted on 163 patients with PTC and exclusive RLN involvement at our institution between 2013 and 2019. Patients were divided into a total thyroidectomy (TT) group and HT group. The clinicopathologic factors and prognostic outcomes were compared between the two groups. A propensity score-matched analysis was carried out to reduce selection bias, with the following covariates: gender, age, tumor size, multifocality, central lymph node metastasis (CLNM), and RLN resection. The Kaplan-Meier method was used for a comparison of recurrence outcomes.

RESULTS

In the baseline data of the 163 PTC patients, tumor size (p < 0.001), multifocality (p = 0.011), CLNM (p < 0.001), and RLN resection (p < 0.008) in the TT and HT groups differed significantly, whereas age and gender did not differ between the two groups. The TT group reported significantly higher temporary and permanent hypoparathyroidism than the HT group (p < 0.001 and p = 0.042, respectively). With 72-month median follow-up, 11 (6.7%) patients developed recurrence. After propensity score matching, 24 patients with HT and 43 patients with TT were included. Recurrence-free survival (RFS) in the matched samples showed no difference between the TT and HT groups (p = 0.092).

CONCLUSION

Our results indicate that HT may be a feasible treatment for PTC patients with exclusive RLN involvement in specific circumstances without significantly increasing the risk of recurrence. Performing a thorough preoperative examination is crucial to exclude multifocal tumors and lymph node metastasis before undergoing HT.

Noticeable effect of lower baseline amplitude on the predictive accuracy of intraoperative amplitude changes for postoperative vocal cord palsy: a prospective cohort study

BACKGROUND

To explore the effect of lower baseline amplitude on its predictive accuracy of postoperative vocal cord paralysis (VCP) in monitored thyroid surgery.

MATERIALS AND METHODS

Clinical and electrophysiological data were collected during thyroid surgeries performed between November and December 2021 at China-Japan Union Hospital. Univariate/multivariate regression analysis were applied to these data to examine a possible correlation. A receiver operating characteristic curve was used to evaluate predictive efficacy.

RESULTS

A total of 631 nerves-at-risk (NAR) were identified in 460 patients who were divided into two groups according to postoperative development of VCP. The VCP group included a higher percentage of NAR with V1<1000 (68.2 vs. 40.7%, respectively; P =0.014) and NAR with R1<1400 (77.3 vs. 47.0%, respectively; P =0.005) compared with the non-VCP group. Multivariate regression analysis further identified V1<1000 [odds ratio (OR)=2.688, P =0.038], R1<1400 (OR=3.484, P =0.018) as independent risk factors for postoperative temporary VCP. The receiver operating characteristic curve showed the AUC value of V signal decline for predicting VCP was 0.87. The diagnostic efficiency of R signal decline reached as high as 0.973. A multivariate logistic regression analysis identified independent risk factors for V1<1000 and these included: higher BMI (OR=1.072, P =0.013), hypertension (OR=1.816, P =0.015), smoking (OR=1.814, P =0.031), and male sex (OR=2.016, P =0.027).

CONCLUSION

In our cohort, lower baseline amplitude was an independent risk factor for developing transient postoperative VCP. It also affected the predictive efficacy of intraoperative amplitude changes on VCP. Higher BMI, hypertension, smoking, and male sex may also be closely associated with lower initial amplitude. Thus, maintaining a higher initial amplitude is critical for patient safety during thyroid surgery.

Recurrent Laryngeal Nerve Intraoperative Neuromonitoring Indications in Non-Thyroid and Non-Parathyroid Surgery

Introperative nerve monitoring (IONM) of the recurrent laryngeal nerve (RLN) is a well-established technique to aid in thyroid/parathyroid surgery. However, there is little evidence to support its use in non-thyroid or non-parathyroid surgery. The aim of this paper was to review the current evidence regarding the use of IONM in non-thyroid/non-parathyroid surgery in the head and neck and thorax. A literature search was performed from their inception up to January 2024, including the term "recurrent laryngeal nerve monitoring". IONM in non-thyroid/non-parathyroid surgery has mainly been previously described in oesophageal surgery and in tracheal resections. However, there is little published evidence on the role of IONM with other resections in the vicinity of the RLN. Current evidence is low-level for the use of RLN IONM in non-thyroid/non-parathyroid surgery. However, clinicians should consider its use in surgery for pathologies where the RLN is exposed and could be injured.

A multichannel electromyography dataset for continuous intraoperative neurophysiological monitoring of cranial nerve

Continuous Intraoperative Neurophysiologic Monitoring (cIONM) is a widely used technology to improve surgical outcomes and prevent cranial nerve injury during skull base surgery. Monitoring of free-running electromyogram (EMG) plays an important role in cIONM, which can be used to identify different discharge patterns, alert the surgeon to potential nerve damage promptly, etc. In this dataset, we collected clinical multichannel EMG signals from 11 independent patients' data using a Neuromaster G1 MEE-2000 system (Nihon Kohden, Inc., Tokyo, Japan). Through innovative classification methods, these signals were categorized into seven different categories. Remarkably, channel 1 and channel 2 captured continuous EMG signals from the facial nerve (VII cranial nerve), while channel 3 to channel 6 focused on V, XI, X, and XII cranial nerves. This is the first time that intraoperative EMG signals have been collated and presented as a dataset and labelled by professional neurophysiologists. These data can be utilized to develop the architecture of neural networks in deep learning, machine learning, pattern recognition, and other commonly employed biomedical engineering research methods, thereby providing valuable information to enhance the safety and efficacy of surgical procedures.

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.

Clinical validation of NerveTrend versus conventional i-IONM mode of NIM Vital in prevention of recurrent laryngeal nerve events during bilateral thyroid surgery: A randomized controlled trial

BACKGROUND

The aim of this study was to test the hypothesis that use of NerveTrend™ mode of intermittent neuromonitoring (i-IONM) during thyroidectomy may identify and prevent impending recurrent laryngeal nerve (RLN) injury.

METHODS

A randomized clinical trial. The primary outcome was prevalence of RLN injury on postoperative day 1. In NerveTrend™ group the i-IONM stimulator was used for trending of amplitude and latency changes from initial vagal electromyographic baseline to tailor surgical strategy.

RESULTS

Some 264 patients were randomized into the intervention versus the control group, 132 patients each. RLN injury was found on postoperative day 1 in 5/264 (1.89%) nerves at risk (NAR) versus 12/258 (4.65%) NAR whereas staged thyroidectomy was used in 0/132 (0.00%) versus 6/132 (4.54%) patients (p = 0.067 and p = 0.029, respectively).

CONCLUSION

The use of NerveTrend™ mode resulted in tendency towards reduced RLN injury on postoperative day 1 and significant decrease of need for a staged thyroidectomy.

Continuous Intraoperative Nerve Monitoring of a Non-Recurrent Laryngeal Nerve: Real-Life Data of a High-Volume Thyroid Surgery Center

Thyroid surgery is associated with a risk of injury to the recurrent laryngeal nerve, especially in the presence of anatomical variants such as a non-recurrent laryngeal nerve (NRLN). Injury to the nerve leads to transient or permanent vocal cord palsy (VCP). A novel method to prevent VCP is continuous intraoperative nerve monitoring (cIONM), but less is known about the applicability of this method in patients with NRLN. The aim of this study was to evaluate our own data regarding feasibility and detailed characteristics of cIONM in NRLN patients. We performed a monocentric retrospective cohort analysis including clinical data and intraoperative nerve monitoring data (measured by Inomed Medizintechnik GmbH, Emmendingen, 'C2' and 'C2 Xplore' device) of all thyroid surgery patients, showing NRLN between 2014 and 2022. Of 1406 patients who underwent thyroid surgery with cIONM between 2014 and 2022, 12 patients (0.9%) showed NRLN intraoperatively. Notably, cIONM was feasible in eight patients (67%). In all cases the onset latency of the right vagus nerve was shorter (<3.0 ms) than usually expected, suggesting that a short latency might be suitable to distinguish NRLN. None of the patients had a post-operative VCP. Overall, cIONM appears to be feasible and safe in NRLN patients and provides helpful information to prevent VCP.

Avoiding Complications of Thyroidectomy: Recurrent Laryngeal Nerve and Superior Laryngeal Nerve Preservation

Both the superior and recurrent laryngeal nerves are at risk for injury during thyroid surgery. Comprehensive preoperative evaluation is key for surgical planning. Exposing nerves through careful dissection is the safest strategy to minimize injury risk. Intraoperative neural monitoring can be beneficial for both identifying and preserving the nerves.

Step-by-Step Thyroidectomy-Incision, Nerve Identification, Parathyroid Preservation, and Gland Removal

Thyroidectomy is a surgical procedure to remove part or all of the thyroid gland. Although the general tenets of surgery have remained the same, improvements in techniques, diagnostics, understanding of anatomy, and technology have allowed thyroid surgery to become a standard, effective, and safe surgery. For surgeons undertaking this procedure, it is imperative to have an in-depth knowledge of critical anatomy and a comprehensive understanding of surgical techniques to perform safe and effective surgery. This article aims to provide an overview of surgical techniques that may be applied in both benign and malignant disease settings.

Comparison of EMG amplitudes recorded by ipsilateral and contralateral electrodes placement during using trans-thyroid cartilage recording method in thyroid surgery

Objectives

The feasibility and reliability of trans-thyroid cartilage EMG recording method (TCERM) during intraoperative monitoring (IONM) of the recurrent laryngeal nerve (RLN) in thyroid surgery have been established. This study compared two different recording electrode placements on the ipsi-lateral and contra-lateral lamina of the thyroid cartilage (TC).

Methods

Fifty consecutive patients undergoing total thyroidectomy with 100 RLNs at risk were enrolled. Two paired subdermal needle electrodes were inserted into the subperichondrium of the bilateral TC lamina to record electromyography (EMG) signals. The channel leads from the TC electrodes were connected to the patient interface with two different modes. In A-mode, the electrode leads were placed ipsi-laterally, and channel 1 monitored the left RLN and channel 2 monitored the right RLN respectively. In B-mode, the electrode leads were placed contra-laterally, and channels 1 and 2 simultaneously monitored the same side of the RLN. The amplitudes of four EMG signals (V1-R1-R2-V2) recorded by A-mode and B-mode were compared.

Results

All EMG amplitudes of V1-R1-R2-V2 signals recorded with B-mode were all above 500μV and significantly higher than those with A-mode (p<0.001). No false loss of signal, electrode dislodgement, or needle-related complications were noted during IONM. Postoperatively, all patients had symmetrical vocal cord movement. Lower EMG amplitudes were observed in older and male patients. Histopathology and laterality showed no significant differences in EMG amplitude.

Conclusion

During using TCERM in thyroid surgery, the recording electrodes should be placed contra-laterally on the TC lamina. This approach ensures high and stable EMG signals, which are important for high-quality IONM of the RLN.

The INMSG Survey on the Loss of Signal Management on the First Side During Planned Bilateral Thyroid Surgery

BACKGROUND

The aim of this study is to describe the management and associated follow-up strategies adopted by thyroid surgeons with different surgical volumes when loss of signal (LOS) occurred on the first side of planned bilateral thyroid surgery, and to further define the consensus on intraoperative neuromonitoring (IONM) applications.

METHODS

The International Neural Monitoring Study Group (INMSG) web-based survey was sent to 950 thyroid surgeons worldwide. The survey included information on the participants, IONM team/equipment/procedure, intraoperative/postoperative management of LOS, and management of LOS on the first side of thyroidectomy for benign and malignant disease.

RESULTS

Out of 950, 318 (33.5%) respondents completed the survey. Subgroup analyses were performed based on thyroid surgery volume: <50 cases/year (n = 108, 34%); 50 to 100 cases/year (n = 69, 22%); and >100 cases/year (n = 141, 44.3%). High-volume surgeons were significantly (P < .05) more likely to perform the standard procedures (L1-V1-R1-S1-S2-R2-V2-L2), to differentiate true/false LOS, and to verify the LOS lesion/injury type. When LOS occurs, most surgeons arrange otolaryngologists or speech consultation. When first-side LOS occurs, not all respondents decided to perform stage contralateral surgery, especially for malignant patients with severe disease (eg, extrathyroid invasion and poorly differentiated thyroid cancer).

CONCLUSIONS

Respondents felt that IONM was optimized when conducted under a collaborative team-based approach, and completed IONM standard procedures and management algorithm for LOS, especially those with high volume. In cases of first-site LOS, surgeons can determine the optimal management of disease-related, patient-related, and surgical factors. Surgeons need additional education on LOS management standards and guidelines to master their decision-making process involving the application of IONM.

Non-recurrent Laryngeal Nerve During Intraoperative Neuromonitoring Thyroidectomy: A Case Report and Literature Review

Complete and precise knowledge of the neck anatomy and its eventual anomalies is crucial while performing a safe thyroid and parathyroid surgery. Embryo-genetic malformations of the IV branchial arch can lead to an uncommon anatomical alteration known as non-recurrent inferior laryngeal nerve. Its prevalence varies between 0.7% for the dextral branch and 0.04% for the sinistral. In these cases, the inferior laryngeal nerve branches originate directly from the cervical vagus nerve, entering the larynx without hooking, on the right side around the subclavian artery or on the left around the aortic arch. The presence of a non-recurrent laryngeal nerve is challenging, due to the increased risks of iatrogenic damage to the nerve, which results in hoarseness, dysphagia, glottal obstruction, vocal cords palsy, and serious airway impairment. We present the case of a 58-year-old woman. The patient was admitted to our department for a nodule classified as Bethesda IV in the right thyroid lobe. Through the use of intraoperative neuromonitoring (IONM), surgeons detected intraoperatively a non-recurrent laryngeal nerve. A subsequent computed tomography scan confirmed an anomalous right subclavian artery branching from the left aortic arch, the Lusoria Artery. Anatomical variants represent pitfalls in this case and an accurate knowledge of the neck region is imperative while performing thyroid surgery. Devices such as IONM are useful for detecting abnormalities that may lead to iatrogenic damages.

Vagus Nerve Stimulation in the Carotid Triangle: An Effective Method for Monitoring the Recurrent Laryngeal Nerve in Thyroid and Parathyroid Surgery

OBJECTIVE

Our objective is the description of the technique of vagus nerve stimulation in carotid triangle in order to monitor the recurrent laryngeal nerve (RLN) during thyroid and parathyroid surgery.

METHODS

We stimulated the vagus nerve in the carotid triangle during 150 thyroid or parathyroid surgeries using a monopolar electromyography electrode inserted under the mastoid process towards the jugular foramen as a cathode, and using another subdermal electrode in the mastoid as an anode. Another complementary method of vagus stimulation was achieved with a pair of subdermal electrodes, placing the cathode at the mandibular angle and the anode at the mastoid.

RESULTS

In all patients, compound muscle action potential (CMAP) was recorded in the vocal cords with both stimulation techniques, allowing semi-continuous monitoring to be carried out. Intraoperative lesions were detected in 16 of the cases; 9 of them were transient with CMAP recovery achieved when modifying surgical maneuvers.

CONCLUSIONS

Vagus nerve stimulation in the carotid triangle is a reliable technique for monitoring the RLN in thyroid surgery. Vagus nerve stimulation in the carotid triangle is effective and safe for RLN monitoring, and it is a clear alternative to direct continuous stimulation of the nerve that by contrast requires its dissection in the carotid sheath.

Intraoperative cricothyroid muscle electromyography may contribute to the monitorization of the external branch of the superior laryngeal nerve during thyroidectomy

Background

In thyroid surgery, both the recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN) should be preserved for maintaining the vocal cord functions. We aimed to evaluate whether EMG of the CTM applied after the superior pole dissection provided additional informative data to the IONM via ETT or not, regarding the EBSLN function.

Methods

The prospectively collected data of the patients, who have undergone thyroidectomy with the use of IONM for the exploration of both the RLN and EBSLN between October 2016 and March 2017, were evaluated retrospectively. Patients over 18 years of age with primary thyroid surgery for malignant or benign thyroid disease, and whom were applied CTM EMG with a needle electrode after the completion of thyroidectomy were included in the study. In the study, each neck side was evaluated as a separate entity considering the EBSLN at risk.

Results

The data of 41 patients (32 female, 9 male) (mean age, 46.7 + 9.1; range, 22-71) were evaluated. Sixty seven EBSLNs out of 26 bilateral and 15 unilateral interventions were evaluated. With EBSLN stimulation after the superior pole dissection, positive glottic EMG waveforms via ETT were obtained in 45 (67.2%) out of 67, and the mean glottic amplitude value was 261 + 191 μV (min-max: 116-1086 μV). Positive EMG responses via the CTM EMG were achieved from all of the 67 EBSLNs (100%) with stimulation using a monopolar probe at the most cranial portion above the area of divided superior pole vessels. The mean value of CTM amplitudes via CTM EMG obtained with EBSLN stimulation was 5268 + 3916 μV (min-max:1215 -19726 μV). With EBSLN stimulation, the mean CTM EMG amplitude was detected significantly higher than the mean vocal cord amplitude (p<0.0001). The CTM EMG provided more objective quantifiable data regarding the EBSLN function (100% vs 67,2%, p<0.001).

Conclusion

In addition to the IONM via ETT, intraoperative post-dissection CTM EMG via needle electrode is a safe, simple and applicable method that may provide significant additional informative data to IONM with ETT by obtaining and recording objective quantitative data related to the EBSLN function.

Facial nerve monitoring in parotid gland surgery: Design and feasibility assessment of a potential standardized technique

Background

Even though the use of nerve monitoring during parotid gland surgery is not the gold standard to prevent damage to the nerve, it surely offers some advantages over the traditional approach. Different from thyroid surgery, where a series of steps in intraoperative nerve monitoring have been described to confirm not only the integrity but-most importantly-the function of the recurrent laryngeal nerve, in parotid gland surgery, a formal guideline to follow while dissecting the facial nerve has yet to be described.

Methods

A five-year retrospective study was done reviewing the intraoperative records of patients who underwent parotid gland surgery under neural monitoring. The operative findings regarding the neuromonitoring process, particularly in regard to the amplitude of two main branches, were revised. A literature search was done to search for guidelines to follow when a facial nerve loss of signal is encountered.

Results

Fifty-five patients were operated on using the Nim 3 Nerve Monitoring System (Medtronic); 31 were female patients, and 47 patients had benign lesions. Minimum changes were observed in the amplitude records after a comparison was made between the first and the last stimulation. There were only three articles discussing the term loss of signal during parotid gland surgery.

Conclusion

Today, no sufficient attention has been given to the facial nerve monitoring process during parotidectomy. This study proposes a formal guideline to follow during this procedure as well as an instruction to consider when a loss of signal is observed to develop a uniform technique of facial nerve stimulation.

Recurrent laryngeal never monitoring versus non-monitoring in parathyroid surgery

Background

Although intraoperative neural monitoring (IONM) is well established in thyroid surgery, it is less commonly analyzed in parathyroid operations. This study presents the results of IONM for primary and secondary hyperparathyroidism surgery.

Methods

We retrospectively assessed 270 patients with primary hyperparathyroidism (PHPT), 53 patients with secondary hyperparathyroidism (SHPT), and 300 patients with thyroid cancer from June 2010 to June 2022 in one hospital in China. The follow-up was 12 months. Demographic, electromyography data from IONM, laboratory, and clinical information were collected. Laryngoscopy was collected from 109 patients with PHPT in whom IONM was not used. All groups were assessed by Pearson's chi-square test and Fisher's exact probability method to verify the relationship between parathyroid size and location, duration of surgery, preoperative concordant localization, laryngeal pain, IONM outcomes, cure rate, and RLN injury. Visual analog scale (VAS) assessed laryngeal pain. RLN outcomes were measured according to nerves at risk (NAR).

Results

The study comprehended 918 NAR, that is 272, 105, 109, and 432 NAR for PHPT, SHPT with IONM, PHPT without IONM, and thyroid surgery control group, respectively. IONM successfully prevented RLN injury (P<0.001, P=0.012): Fifteen (5.51%) RLNs experienced altered nerve EMG profiles during surgery, and five (1.84%) experienced transient RLN injury in PHPT patients. Five (4.76%) RLNs were found to have altered EMG profiles during surgery, and one (0.95%) RLN had a transient RLN injury in SHPT patients. There was no permanent nerve injury (0.00%) in this series. There was no association between location, gland size, preoperative concordant localization, cure rate, duration of surgery, and IONM (P >0.05). Duration of surgery was associated with postoperative pharyngeal discomfort (P=0.026, P=0.024). Transient RLN injury was significantly lower in patients with PHPT who underwent IONM than in those who did not. Intraoperative neuromonitoring played an effective role in protecting the recurrent laryngeal nerve (P=0.035). Compared with parathyroidectomy, thyroidectomy had a higher rate of RLN injury (5.32%, P<0.001).

Conclusion

IONM for SHPT and PHPT offers rapid anatomical gland identification and RLN functional results for effective RLN protection and reduced RLN damage rates.

Endoscopic thyroidectomy via areola approach for stage T1 papillary thyroid carcinoma: feasibility, safety, and oncologic outcomes

Purpose

To evaluate the feasibility, safety, and oncologic outcomes associated with endoscopic thyroidectomy via the areolar approach (ETAA), compared with conventional open thyroidectomy (COT) for the treatment of stage T1 papillary thyroid carcinoma (PTC).

Methods

Between January 2021 and June 2022, a total of 1204 patients diagnosed with PTC underwent screening, out of which 138 patients were selected for inclusion in the study population after propensity score matching (92 patients in the ETAA group and 46 patients in the COT group). The study included the collection and analysis of clinicopathologic characteristics, intraoperative outcomes, postoperative outcomes, complications, and follow-up data using R software.

Results

The operative time for the ETAA group was longer than that for the COT group (160.42 ± 32.21 min vs. 121.93 ± 29.78 min, p < 0.0001). However, there were no significant differences between the two groups in terms of intraoperative blood loss, the extent of surgical resection, the number of dissected lymph nodes, the number of metastatic lymph nodes, and the rate of parathyroid autotransplantation. Postoperative drainage and C-reactive protein levels were higher in the ETAA group than in the COT group, but there were no significant differences in 24-hour visual analogue scale scores, white blood cell counts, drainage duration, or postoperative hospital stay. Complication rates were similar between the two groups, and no permanent recurrent laryngeal nerve palsy or hypoparathyroidism was observed. Patients who underwent ETAA reported greater cosmetic satisfaction and quality of life than those who underwent COT. During the follow-up phase, only one patient in the COT group developed lateral cervical lymph node involvement requiring reoperation.

Conclusion

ETAA is a safe and feasible surgical method for patients with stage T1 PTC, providing results similar to COT in terms of oncologic completeness, while avoiding neck scars, with excellent cosmetic effects.

Clinical trial registration

Chinese Clinical Trial Registry center, identifier ChiCTR2300077109.

Assessment of different classification systems for predicting the risk of superior laryngeal nerve injury during thyroid surgery: a prospective cohort study

Background

A multitude of anatomical variations have been noted in the external branch of the superior laryngeal nerve (EBSLN). In this study, intraoperative neuromonitoring (IONM) was used to assess the potential value of the different classical EBSLN classifications for predicting the risk of EBSLN injury.

Methods

In total, 136 patients with thyroid nodules were included in this prospective cohort study, covering 242 nerves at risk (NAR). The EBSLN was identified by observing the cricothyroid muscle twitch and/or typical electromyography (EMG) biphasic waveform. The EBSLNs were classified by Cernea classification, Kierner classification, and Friedman classification, respectively. The EMG parameters and outcomes of vocal acoustic assessment were recorded.

Results

The distribution of Cernea, Kiernea, and Friedman subtypes were, respectively, Cernea 1 (40.9%), Cernea 2A (45.5%), Cernea 2B (10.7%), Kierner 1 (40.9%), Kierner 2 (45.5%), Kierner 3 (10.7%), Kierner 4 (2.9%) and Friedman 1 (15.7%), Friedman 2 (33.9%), Friedman 3 (50.4%). The amplitudes of EBSLN decreased significantly after superior thyroid pole operation, respectively, in Cernea 2A (193.7 vs. 226.6μV, P=0.019), Cernea 2B (185.8 vs. 221.3μV, P=0.039), Kierner 2 (193.7vs. 226.6μV, P=0.019), Kierner 3 (185.8 vs. 221.3μV, P=0.039), Kierner 4 (126.8vs. 226.0μV, P=0.015) and Friedman type 2 (184.8 vs. 221.6μV, P=0.030). There were significant differences in Fmax and Frange for Cernea 2A (P=0.001, P=0.001), 2B (P=0.001, P=0.038), Kierner 2 (P=0.001), Kierner 3 (P=0.001, P=0.038), and Friedman 2 (P=0.004, P=0.014). In the predictive efficacy of EBSLN injury, the Friedman classification showed higher accuracy (69.8% vs. 44.3% vs. 45.0%), sensitivity (19.5% vs. 11.0% vs. 14.0%), and specificity (95.6% vs. 89.9% vs. 89.9%) than the Cernea and Kierner classifications. However, the false negative rate of Friedman classification was significantly higher than other subtypes (19.5% vs. 11.0% vs. 14.0%).

Conclusion

Cernea 2A and 2B; Kierner 2, 3, and 4; and Friedman 2 were defined as the high-risk subtypes of EBSLN. The risk prediction ability of the Friedman classification was found to be superior compared to other classifications.

Comparison of transoral endoscopic thyroidectomy vestibular approach and open conventional thyroidectomy regardıng inflammatory responses, pain, and patient satisfaction: a prospective study

Introduction

The application of transoral endoscopic thyroidectomy vestibular approach (TOETVA) is becoming widespread throughout the world. We primarily aimed to evaluate the severity of surgical trauma in TOETVA and conventional open thyroidectomy (COT) regarding the inflammatory response including the comparison of surgical stress markers [interleukin-6 (IL-6), C-reactive protein (CRP), white blood cell (WBC)].

Material and method

This non-randomized prospective study enrolled two groups with 20 patients each: COT group and TOETVA group. Patients aged 18-65 years with benign thyroid disease; with fine needle aspiration biopsy results of Bethesda III, IV or Bethesda V, VI (<1 cm nodule); thyroid volume <50 cm3; nodule diameter <4 cm; female gender without a previous neck, chin, and/or oral surgery; without vocal cord paralysis preoperatively; and patients in euthyroid state were enrolled to the study. Preoperative, postoperative second hour, first day, and second day CRP, WBC, and IL-6 levels were evaluated. Pain intensity was evaluated with the visual analog scale (VAS) score on the 2nd and 12th hour, 1st and 2nd days postoperatively.

Results

All the patients were female and mean age was significantly higher in the COT group. The operative time was significantly longer in the TOETVA group. No significant difference was found between the two groups regarding IL-6 levels. In the TOETVA group, postoperative second hour WBC value (p = 0.044) and first (p = 0.002) and second day (p = 0.005) CRP values were significantly higher. In the TOETVA group, the lower lip and lower chin VAS scores were significantly higher at 2nd and 12th hour, on the first and second days. The anterior neck VAS score was significantly higher in the TOETVA group at the second hour (p = 0.025). General and cosmetic satisfactions were similar at the 15th and 30th days in both groups.

Conclusion

The longer operative time and higher postoperative CRP level and VAS score in the chin and lower lip in the TOETVA group suggested that the method is not a minimally invasive technique compared to COT. However, the presence of similar total complication rates and early postoperative general and esthetic satisfaction that improves over time in both groups suggests that the clinical effect of increased magnitude of systemic inflammatory response in TOETVA might be temporary and acceptable.

Surgical and Biochemical Outcomes in Nerve Monitored Reoperation Surgery for Recurrent Papillary Thyroid Carcinoma

OBJECTIVE

To study the surgical and biochemical outcomes in nerve-monitored reoperation or revision surgery for recurrent thyroid cancers.

STUDY DESIGN

A single-center retrospective study.

SETTING

Tertiary center.

METHODS

We identified patients with recurrent papillary thyroid carcinoma (PTC) who underwent reoperation/revision surgery. Study outcomes were surgical complications frequency, recurrence, distant metastasis, and biological complete response (BCR) by comparing preoperative and postoperative thyroglobulin (Tg) levels.

RESULTS

Out of 227 patients, 33.9% presented for ≥2 reoperation surgeries. Nineteen (8.4%) had permanent preoperative hypoparathyroidism while 22 patients (9.7%) had preoperative vocal cord paralysis (VCP). Following reoperation surgery, there were 12 cases (5.3%) of permanent hypocalcemia and no cases of unexpected postoperative VCP. BCR was achieved in 31 patients (35.2%) with complete Tg data. Mean preoperative Tg was 47.7 ng/mL and was 19.7 ng/mL postoperatively (p = .003). The cervical nodal recurrence rate after final surgery was 7.0% (n = 16).

CONCLUSION

Reoperation surgery for recurrent PTC may help achieve biochemical remission regardless of age or the number of prior surgeries.

Technical aspects of a new approach to intraoperative pelvic neuromonitoring during robotic rectal surgery

It has been found that rectal surgery still leads to high rates of postoperative urinary, fecal, or sexual dysfunction, which is why nerve-sparing surgery has gained increasing importance. To improve functional outcomes, techniques to preserve pelvic autonomic nerves by identifying anatomic landmarks and implementing intraoperative neuromonitoring methods have been investigated. The objective of this study was to transfer a new approach to intraoperative pelvic neuromonitoring based on bioimpedance measurement to a clinical setting. Thirty patients (16 male, 14 female) involved in a prospective clinical investigation (German Clinical Trials Register DRKS00017437, date of first registration 31/03/2020) underwent nerve-sparing rectal surgery using a new approach to intraoperative pelvic neuromonitoring based on direct nerve stimulation and impedance measurement on target organs. Clinical feasibility of the method was outlined in 93.3% of the cases. Smooth muscle contraction of the urinary bladder and/ or the rectum in response to direct stimulation of innervating functional nerves correlated with a change in tissue impedance compared with the pre-contraction state. The mean amplitude (Amax) of positive signal responses was Amax = 3.8%, negative signal responses from a control tissue portion with no stimulation-induced impedance change had an amplitude variation of 0.4% on average. The amplitudes of positive and negative signal responses differed significantly (statistical analysis using two-sided t-test), allowing the nerves to be identified and preserved. The results indicate a reliable identification of pelvic autonomic nerves during rectal surgery.

A Neural Integrity Monitor Electromyography Endotracheal Tube Causes More Severe Postoperative Sore Throat Than a Standard Endotracheal Tube in Adults: A Prospective Cohort Study

BACKGROUND

This study aimed at figuring out the different effects of a neural integrity monitor electromyography endotracheal tube (NIM-EMG-ETT) and a standard endotracheal tube (ETT) on postoperative sore throat (POST).

METHODS

This prospective cohort study enrolled 143 patients scheduled to undergo general anesthesia with endotracheal intubation. Patients were allocated into three groups: Group A, non-thyroid surgery with a standard ETT; Group B, thyroid surgery with a standard ETT; Group C, thyroid surgery with a NIM-EMG-ETT. The incidence, the severity and visual analog scale (VAS) of POST were recorded. The incidence and the severity of POST were tested by χ2 test or Fisher's exact test. And VAS of POST was tested by Kruskal-Wallis test.

RESULTS

The incidences of POST in Group B and Group C were significantly higher than that of Group A at all the time points after extubation (P < 0.001). The incidences of POST in Group C was significantly higher than that in Group B at 8 h, 24 h and 48 h after extubation (89.4% vs. 68.8%, P = 0.014, relative risk (RR) 1.30, 95% confidence interval (CI) 1.05-1.61; 89.4% vs. 58.3%, P = 0.001, RR 1.53, 95% CI 1.18-1.98; 76.6% vs. 45.8%, P = 0.002, RR 1.67, 95% CI 1.18-2.36). Moreover, there was a significant higher VAS of POST and more serious POST with Group C than with Group B.

CONCLUSIONS

A NIM-EMG-ETT may induce higher incidence of POST and more serious POST than a standard ETT.

TRAIL REGISTRATION

Chinese Clinical Trail Registry ( http://www.chictr.org.cn/index.aspx , ChiCTR2200058896, 2022-4-18).

Comparison of intraoperative neural monitoring between endoscopic transoral and bilateral axillo-breast approach thyroidectomy

BACKGROUND

The use of intraoperative neuromonitoring (IONM) during endoscopic thyroidectomy has not been fully explored, with limited studies focusing solely on the recurrent laryngeal nerve (RLN) and neglecting the external branch of the superior laryngeal nerve (EBSLN). This study aimed to compare the effectiveness of IONM in two endoscopic thyroidectomy techniques, namely the transoral and bilateral axillo-breast approach (BABA).

METHODS

We retrospectively reviewed patients who underwent endoscopic thyroidectomy with IONM and compared the outcomes between those who underwent different surgical techniques (transoral or BABA). We recorded the detection method and identification rate of the EBSLN and RLN, along with the amplitude and latency of the evoked potential.

RESULTS

We monitored 98 nerves at risk (NAR) from 74 patients (60 and 38 in the transoral and BABA groups, respectively). Almost all EBSLNs were identified using electromyography (EMG) signals and/or cricothyroid muscle twitches, except for one patient in the transoral group who developed EBSLN palsy. Patients in the transoral group were more likely to have the sternothyroid muscle divided (75.0% vs. 15.8%, p < 0.001) and had a lower rate of visual recognition of the EBSLN fibers (10.0% vs. 31.6%, p = 0.007) than did those in the BABA group. All RLNs were identified in both groups; however, patients in the BABA group had a relatively higher rate of post-dissection amplitude reduction > 50% (15.8% vs. 5.0%, p = 0.072), and one patient had transient RLN palsy.

CONCLUSIONS

Both the EBSLN and RLN could be adequately identified and monitored during endoscopic transoral and BABA thyroidectomies using IONM.

Re-operative surgery for differentiated thyroid cancer: A single institutional experience of 182 cases

INTRODUCTION

Re-operative thyroid surgery (RTS) is performed in patients of differentiated thyroid cancer (DTC) with residual or recurrent disease. However, there is a paucity of literature discussing experience and technique of RTS. This study aims to address this gap by providing a comprehensive review of RTS for DTC, utilizing experiences from a dedicated complex thyroid surgical oncology program at the apex hospital in a developing country.

METHODS

A retrospective analysis was conducted using data from the Department of Surgical Oncology's thyroid cancer database. The study period spanned from 2006 to 2022. Clinical presentation, prior surgical history, operative details of RTS, and post-operative outcomes were assessed. Descriptive analysis was performed.

RESULTS

During the study period, a total of 182 patients underwent re-operative thyroid surgery (RTS). The primary surgeries performed prior to RTS included near-total or total thyroidectomy in most cases (69.2%), and approximately half of the patients (48.4%) had prior neck node interventions. The RTS procedures consisted of completion total thyroidectomy in 30.8% of cases and surgery for thyroid bed recurrence in 9.9% of cases, while central node dissection was performed in 46.2% of patients and unilateral or bilateral template neck dissection was performed in 41.8% of cases. Extended resections were required in 9.3% of patients. Post-operative complications included permanent hypoparathyroidism (2.7%) and unilateral recurrent laryngeal nerve palsy (1.6%).

CONCLUSIONS

RTS is a complex procedure with high rates of post-operative morbidity reported in literature. Optimal outcomes require a multidisciplinary approach, thorough assessment, and skilled surgeons.