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

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.

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.

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.

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.

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.

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.

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 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.

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.

Effects of Endotracheal Tube with Adhesive Superficial Laryngeal Electrodes for Intraoperative Nerve Monitoring on Laryngopharyngeal Complications during Thyroidectomy

The endotracheal tube (ETT) with laryngeal adhesive electrodes for intraoperative neural monitoring (IONM) may be related to laryngopharyngeal complications, such as postoperative sore throat (POST), hoarseness, and coughing. We aimed to evaluate the effects of the ETT with laryngeal adhesive electrodes for IONM on the occurrence of laryngopharyngeal complications during thyroidectomy. In this retrospective study, we included 176 patients who underwent thyroidectomy for thyroid cancer between September 2020 and February 2021. The patients were categorized into control (n = 108) and IONM (n = 68) groups. Patients in the IONM group were intubated with the ETT with surface electrodes. Characteristics of the patients and surgery, perioperative variables, and laryngopharyngeal complications, including POST, hoarseness, and cough, were evaluated. The severity and incidence of POST were comparable between the two groups on postoperative days 0, 1, and 2 (p = 0.103, 0.386, and 0.056, respectively). Furthermore, no significant differences were observed in the occurrence of postoperative hoarseness and cough between the groups. The ETT with laryngeal adhesive electrodes for IONM during thyroidectomy did not affect the incidence and severity of postoperative laryngopharyngeal complications, including POST, hoarseness, and cough. Further prospective, double-blinded, randomized clinical trials are required to gain a clearer understanding.

A study on the appropriate dose of rocuronium for intraoperative neuromonitoring in Da Vinci robot thyroid surgery: a randomized, double-blind, controlled trial

Background

This study was to explore the effect of different doses of rocuronium bromide on neuromonitoring during Da Vinci robot thyroid surgery.

Methods

This was a prospective, randomized, double-blind, controlled trial that included 189 patients who underwent Da Vinci robot thyroidectomy with intraoperative neuromonitoring(IONM). Patients were randomly divided into three groups and given three different doses of rocuronium (0.3mg/kg, 0.6mg/kg, 0.9mg/kg). Outcome measurements included IONM evoked potential, postoperative Voice Handicap Index-30(VHI-30), intraoperative body movement incidence rate, Cooper score, and hemodynamic changes during anesthesia induction.Results: The difference in IONM evoked potentials at various time points between the three groups was not statistically significant (P>0.05). The difference in Cooper scores and intraoperative body movement incidence rate between 0.6 and 0.9mg/kg groups was statistically significant compared with the 0.3mg/kg group (both P<0.001). There was no statistically significant difference in VHI-30 score and hemodynamic changes during anesthesia induction among the three groups (both P>0.05).

Conclusions

For patients undergoing Da Vinci robot thyroidectomy, a single dose of rocuronium at 0.6 and 0.9mg/kg during anesthesia induction can provide stable IONM evoked potential. Additionally, compared to 0.3 mg/kg, it can offer better tracheal intubation conditions and lower incidence of body movements during surgery. It is worth noting that the use of higher doses of rocuronium should be adjusted based on the duration of IONM and local practices.

The Utility of Intraoperative Neuromonitoring in Pediatric Surgical Oncology

BACKGROUND

Intraoperative nerve monitoring (IONM) is a technique used to decrease the possibility of nerve-associated morbidity and damage to nearby neural structures during complex surgical procedures. The use and potential benefits of IONM in pediatric surgical oncology are not well-described.

METHODS

An overview of the current literature was performed to elucidate the various techniques that may be useful to pediatric surgeons for resection of solid tumors in children.

RESULTS

The physiology and common types of IONM relevant to the pediatric surgeon are described. Important anesthetic considerations are reviewed. Specific applications for IONM that may be useful in pediatric surgical oncology are then summarized, including its use for monitoring the recurrent laryngeal nerve, the facial nerve, the brachial plexus, spinal nerves, and lower extremity nerves. Troubleshooting techniques regarding common pitfalls are then proposed.

CONCLUSION

IONM is a technique that may be beneficial in pediatric surgical oncology to minimize nerve injury during extensive tumor resections. This review aimed to elucidate the various techniques available. IONM should be considered as an adjunct for the safe resection of solid tumors in children in the proper setting with the appropriate level of expertise. A multidisciplinary approach is advised. Additional studies are necessary to further clarify the optimal use and outcomes in this patient population.

LEVELS OF EVIDENCE

Level III.

Management of surgical diseases of thyroid gland indications of the United Italian Society of Endocrine Surgery (SIUEC)

A task force of the United Italian society of Endocrine Surgery (SIUEC) was commissioned to review the position statement on diagnostic, therapeutic and health‑care management protocol in thyroid surgery published in 2016, at the light of new technologies, recent oncological concepts, and tailored approaches. The objective of this publication was to support surgeons with modern rational protocols of treatment that can be shared by health-care professionals, taking into account important clinical, healthcare and therapeutic aspects, as well as potential sequelae and complications. The task force consists of 13 members of the SIUEC highly trained and experienced in thyroid surgery. The main topics concern clinical evaluation and preoperative workup, patient preparation for surgery, surgical treatment, non-surgical options, postoperative management, prevention and management of major complications, outpatient care and follow-up.

History of Thyroid Surgery in the Last Century

Before the 20th century, thyroid surgery was regarded as "horrid butchery" such that no honest and sensible surgeon would ever engage in it. Yet, by the mid-20th century, thyroidectomy had become a respected, life-saving, safe, and increasingly practiced operation. From Kocher to Wells and onward into the 21st century, the evolution of thyroid surgery has continued, enhanced by the integration of endocrinology, genetics, immunology, physiology, technology, training, and multidisciplinary care. The ability to personalize and optimize the care of thyroid disorders has been progressively achieved through shared insights and discoveries, highlights of which are described herein.

The Feasibility Study of Intraoperative RLN Monitoring Using Cricothyroid Membrane-Inserted Needle Electrodes During Thyroid Surgery

OBJECTIVE

This study evaluated the feasibility, stability, safety, and economy of cricothyroid membrane (CM)-inserted needle electrodes for recurrent laryngeal nerve monitoring.

STUDY DESIGN

Parallel and controlled study.

SETTING

Clinical research center for thyroid diseases of Shaanxi province.

METHODS

A total of 64 patients in the needle electrodes group (104 recurrent laryngeal nerves [RLNs]) and 44 patients in the endotracheal tube (ETT)-based electrodes group (80 RLNs) underwent monitored thyroidectomy. The evoked electromyography (EMG) signals detected by the 2 electrodes were recorded and analyzed. The changes in EMG during Berry's ligament traction and tracheal displacement were compared. All patients underwent preoperative and postoperative laryngoscopy within 1 week.

RESULTS

Both electrodes successfully recorded typical evoked laryngeal EMG waveforms from RLNs. The needle electrodes recorded relatively higher amplitudes and similar latencies compared to ETT-based electrodes. The evoked EMG signals attributed to needle electrodes could accurately predict the function of RLNs with 100% sensitivity and specificity. The reduction in the recorded amplitudes attributed to needle electrodes was higher than that observed with ETT-based electrodes during Berry's ligament traction or trachea displacement, whereas a similar increase in the latencies was recorded in the 2 groups. Particularly, Berry's ligament traction was more likely to lead to EMG amplitude reduction and latency prolongation. The needle electrodes group recorded 2 cases of minor bleeding on the CM. The needle electrodes were more cost-effective than ETT-based electrodes.

CONCLUSION

The CM-inserted needle electrodes are feasible, stable, safe, and economical for RLN monitoring, and they provide an alternative novel intraoperative neural monitoring format for thyroid surgeons.

Morbidity and mortality among neonates with esophageal atresia and/or tracheoesophageal fistula in the United States

BACKGROUND

Although rare, esophageal atresia (EA) and/or tracheoesophageal fistula (TEF) can lead to severe morbidity and mortality. A known complication of EA and/or TEF repair is vocal fold motion impairment (VFMI).

OBJECTIVE

To characterize the prevalence of VFMI among repaired EA and/or TEF at a national level and to identify factors associated with in-patient mortality and common clinical endpoints in this population (tracheostomy and gastrostomy tube dependence).

METHODS

This is a retrospective cohort study of inpatient neonate admissions with EA and/or TEF in the 2016 Kids' Inpatient Database (KID). Patients with a history of EA and/or TEF were identified with ICD-10 codes. VFMI prevalence was assessed by observed frequencies and percentages. Clinical endpoints included gastrostomy (G-)tube placement, tracheostomy status, and inpatient mortality. Potential predictors of these three primary outcomes included cardiac anomalies, airway disorders, chromosomal anomalies, surgery within 24 h of admission, prematurity, and low birthweight (LBW). Chi-squared analysis was performed between each parameter and the primary outcomes. Significant associations (p-value<0.05) were further assessed with multivariate logistic regression.

RESULTS

Of 1062 neonates with history of EA and/or TEF, 24 (2.3%) had VFMI. Among this population, 27 patients underwent tracheostomies and 63 required G-tubes. There was a significantly higher likelihood of tracheostomy in patients with VFMI compared to patients without (16.7% versus 2.2%; p < 0.01). After multivariate analysis, birthweight less than 1.5 kg (BW < 1.5 kg; OR = 2.5, 95% CI: 1.03-6.10), extreme prematurity (OR = 7.5, 95% CI: 2.00-28.07), cardiac anomalies (OR = 1.8, 95% CI: 1.01-3.04) and chromosomal anomalies (OR = 4.2, 95% CI: 2.39-7.44) were significantly associated with in-hospital mortality. Bronchopulmonary dysplasia (BPD; OR = 4.7, 95% CI: 1.73-12.78) and BW < 1.5 kg (OR = 2.4, 95% CI: 1.05-5.49) were significant predictors for G-tube status. For tracheostomy, BPD (OR = 15.8, 95% CI: 4.70-52.83) and subglottic stenosis (SS, OR = 11.2, 95% CI: 1.85-68.02) remained significant predictors after multivariate regression.

CONCLUSION

The national prevalence of VFMI among neonates following EA and/or TEF repair was 2.3% and was associated with an increased likelihood of tracheostomy in the KID 2016. Significant predictors of in-hospital mortality were cardiac anomalies, chromosomal anomalies, extreme prematurity, and BW < 1.5 kg. BPD and SS were significant predictors of tracheostomy, and BPD and BW < 1.5 kg were significant predictors for G-tube requirements.

A Comparison of Completeness and Complication of Total Thyroidectomy with or Without Neuromonitoring

Objectives

Total Thyroidectomy (TT) in true sense is not total as evidenced by remnant uptake in radio-iodine scans and serum thyroglobulin. The aim of this study is to assess the completeness of TT, operating time and recurrent laryngeal nerve injury with and without neuro-monitoring (IONM).

Methods

Cross sectional analytical study using retrospective data of patients undergoing total thyroidectomy for benign and malignant goiters. Surgeries performed by single surgeon. Patients undergoing TT (2015-22) were grouped into Group A (n = 400) and Group B (n = 400) based on use of IONM. Subgroup of patients (Group A1&B1) who had differentiated thyroid cancer were compared for completeness of thyroidectomy with DxWBS and serum thyroglobulin (TG). Group A and B were compared for operating time and incidence of RLN palsy.

Results

Of the 800 RLN at risk transient RLN palsy was lower with IONM (p = 0.048). Mean operating time was significantly higher in Group-B(p = 0.0038). Subgroup A1 showed lower radio-active iodine uptake percentage, higher number of patients with negative scan, TG of < 1ng/mL indicating better completeness of TT.

Conclusion

Our study shows better completeness of thyroidectomy, lower incidence of transient RLN palsy and shorter operating time with IONM.

Modern Surgical Techniques of Thyroidectomy and Advances in the Prevention and Treatment of Perioperative Complications

Thyroid cancer is the most common cancer of the endocrine system, and, in recent years, there has been a phenomenon of overdiagnosis followed by subsequent overtreatment. This results in an increasing number of thyroidectomy complications being faced in clinical practice. In this paper, we present the current state of knowledge and the latest findings in the fields of modern surgical techniques, thermal ablation, the identification and assessment of parathyroid function, recurrent laryngeal nerve monitoring and treatment and perioperative bleeding. We reviewed 485 papers, from which we selected 125 papers that are the most relevant. The main merit of this article is its comprehensive view of the subject under discussion-both general, concerning the selection of the appropriate method of surgery, and particular, concerning the selection of the appropriate method of prevention or treatment of selected perioperative complications.

Place of laryngoscopy and neuromonitoring in thyroid surgery. Recommendations of the AFCE (Association francophone de chirurgie endocrinienne) with the SFE (Société française d'endocrinologie) and the SFMN (Société française de médecine nucléaire)

Preoperative laryngoscopy is mandatory when there is a history of cervical or thoracic surgery, dysphonia, posteriorly developed thyroid carcinoma, or significant lymph node involvement in the central compartment. Postoperative laryngoscopy should be performed for any postoperative dysphonia, swallowing difficulties, respiratory symptoms, or loss of signal during neuromonitoring of the recurrent and/or vagus nerve. Neuromonitoring can be useful in thyroid surgery because it lowers the rate of transient recurrent palsy (RP), although no impact on permanent RP has been demonstrated. It facilitates location of the recurrent nerve. Continuous neuromonitoring of the vagus nerve can, in some situations, allow early detection of a signal drop during dissection near the recurrent nerve.

Remimazolam Anesthesia for Thyroid Surgery

Background

Critical upper airway obstruction, hematoma formation, and recurrent laryngeal nerve palsy have been reported as postoperative complications of thyroid surgery. Although remimazolam may reduce the risk of these complications, the efficacy of flumazenil with remimazolam has not been reported. We present the successful anesthesia management of thyroid surgery using remimazolam and flumazenil. Case Presentation. A 72-year-old woman was diagnosed with a goiter and scheduled for a partial thyroidectomy under general anesthesia. We used remimazolam for induction and maintenance using a neural integrity monitor, electromyogram, and endotracheal tube under the bispectral index monitor. At the end of the surgery, spontaneous respiration was confirmed after the intravenous administration of sugammadex, and the patient was extubated under mild sedation. In the operating room, we administered flumazenil intravenously to confirm recurrent laryngeal nerve palsy and active postoperative hemorrhage. The patient was confirmed to have no recurrent laryngeal nerve palsy under full wakefulness but developed active postoperative hemorrhage with normal blood pressure. The patient required reoperation and was reintubated under intravenous administration of propofol. The anesthesia was maintained using 5% of desflurane, and the patient was extubated without any postoperative problems. The anesthesia was then terminated. The patient had no recall of the procedure.

Conclusion

Maintenance of general anesthesia using remimazolam allowed the use of a neurostimulator with minimal muscle-relaxant effects, and extubation under sedation reduced the risk of abrupt and unexpected changes in blood pressure, body movement, and coughing. Furthermore, after extubation, the patient was rendered fully awake using flumazenil to confirm the presence of recurrent laryngeal nerve palsy and active postoperative hemorrhage. In addition, the patient had no memory of the reoperation, suggesting that the anterograde amnesic effect of remimazolam had a favorable psychological outcome associated with the reoperation. We safely managed thyroid surgery using remimazolam and flumazenil.

Safety of continuous intraoperative vagus nerve neuromonitoring during thyroid surgery

BACKGROUND

Continuous intraoperative neuromonitoring has successfully demonstrated to predict impending damage to the recurrent laryngeal nerve, by detecting changes in electromyographic recordings. Despite the apparent benefits associated with continuous intraoperative neuromonitoring, its safety is still a debate. The aim of this study was to investigate the electrophysiological impact of continuous intraoperative neuromonitoring on the vagus nerve.

METHODS

In this prospective study, the amplitude of the electromyographic wave of the vagus nerve-recurrent laryngeal nerve axis was measured both proximally and distally to the stimulation electrode placed upon the vagus nerve. Electromyographic signal amplitudes were collected at three distinct events during the operation: during the dissection of the vagus nerve, before application of the continuous stimulation electrode onto the vagus nerve and after its removal.

RESULTS

In total, 169 vagus nerves were analysed, among 108 included patients undergoing continuous intraoperative neuromonitoring-enhanced endocrine neck surgeries. Electrode application resulted in a significant overall decrease in measured proximo-distal amplitudes of -10.94 µV (95 per cent c.i. -17.06 to -4.82 µV) (P < 0.005), corresponding to a mean(s.d.) decrease of -1.4(5.4) per cent. Before the removal of the electrode, the measured proximo-distal difference in amplitudes was -18.58 µV (95 per cent c.i. -28.31 to -8.86 µV) (P < 0.005), corresponding to a mean(s.d.) decrease of -2.50(9.59) per cent. Seven nerves suffered a loss of amplitude greater than 20 per cent of the baseline measurement.

CONCLUSION

In addition to supporting claims that continuous intraoperative neuromonitoring exposes the vagus nerve to injury, this study shows a mild electrophysiological impact of continuous intraoperative neuromonitoring electrode placement on the vagus nerve-recurrent laryngeal nerve axis. However, the small observed differences are negligible and were not associated with a clinically relevant outcome, making continuous intraoperative neuromonitoring a safe adjunct in selected thyroid surgeries.

Multimodal Analgesia with Local Wound Infiltration and Intravenous Parecoxib for Thyroidectomy

Background and objective: Adequate postoperative pain control is an important component to enhance recovery. Multimodal analgesia with various pain control techniques has been widely used to alleviate postoperative pain. The use of either wound infiltration or a superficial cervical plexus block has been reported to be effective for pain management after thyroid surgery. The present study evaluated the effect of multimodal analgesia using lidocaine wound infiltration combined with intravenous parecoxib for patients monitored after thyroidectomy. Materials and Methods: A total of 101 patients with a multimodal analgesia protocol being monitored after thyroidectomy were enrolled. After the induction of anesthesia, multimodal analgesia was performed through wound infiltration of 1% lidocaine and epinephrine at a ratio of 1:200,000 (5 μg/mL) combined 40 mg intravenous parecoxib before skin excision. Patients were divided into two groups for this retrospective analysis based on the injection dose of lidocaine they received. Patients in Group I (the control, n = 52) received a 5 mL injection solution, while those in Group II (the study, n = 49) received a 10 mL dosage in a time-sequential manner, in accordance with a previous clinical trial. The primary outcome was measuring postoperative pain intensity at rest, as well as during motion and coughing, which was measured at the postoperative anesthetic care unit (PACU) and on the first day after the operation (POD 1) in the ward. Pain intensity was assessed using a numerical rating scale (NRS). The secondary outcomes were postoperative adverse events including anesthetic-related side effects, as well as airway and pulmonary complications. Results: Most of the patients reported no pain or mild pain during the observation period. The patients in Group II had a lower pain intensity during motion than Group I (NRS 1.47 ± 0.89 vs. 1.85 ± 0.96, p = 0.043) when measured at the postoperative anesthetic care unit. Pain intensity during coughing was also significantly lower in the study group than in the control group (NRS 1.61 ± 0.95 vs. 1.96 ± 0.79, p = 0.049) when measured at the postoperative anesthetic care unit. There were no severe adverse events in either of the groups. Only one patient (1.9%) in Group I experienced temporary vocal palsy. Conclusions: The use of lidocaine with an equal volume of intravenous parecoxib provided comparable analgesia with minimal adverse events when monitoring thyroidectomy.

A Prospective Study of Electromyographic Amplitude Changes During Intraoperative Neural Monitoring for Open Thyroidectomy

BACKGROUND

Intraoperative nerve monitoring (IONM) of the vagus and recurrent laryngeal nerve (RLN) enables prediction of postoperative nerve function. The underlying mechanism for loss of signal (LOS) in a visually intact nerve is poorly understood. The correlation of intraoperative electromyographic amplitude changes (EMG) with surgical manoeuvres could help identify mechanisms of LOS during conventional thyroidectomy.

METHODS

A prospective study of consecutive patients undergoing thyroidectomy was performed with intermittent IONM using the NIM Vital nerve monitoring system. The ipsilateral vagus and RLN was stimulated, and vagus nerve signal amplitude recorded at five time points during thyroidectomy (baseline, after mobilisation of superior pole, medialisation of the thyroid lobe, before release at Ligament of Berry, end of case). RLN signal amplitude was recorded at two time points; after medialisation of the thyroid lobe (R1), and end of case (R2).

RESULTS

A total of 100 consecutive patients undergoing thyroidectomy were studied with 126 RLN at risk. The overall rate of LOS was 4.0%. Cases without LOS demonstrated a highly significant vagus nerve median percentage amplitude drop at medialisation of the thyroid lobe (- 17.9 ± 53.1%, P < 0.001), and end of case (- 16.0 ± 47.2%, P < 0.001) compared to baseline. RLN had no significant amplitude drop at R2 compared to R1 (P = 0.207).

CONCLUSIONS

A significant reduction in vagus nerve EMG amplitude at medialisation of the thyroid and the end of case compared to baseline indicates that stretch injury or traction forces during thyroid mobilisation are the most likely mechanism of RLN impairment during conventional thyroidectomy.

Mechanisms of recurrent laryngeal nerve injury in endoscopic thyroidectomy for papillary thyroid carcinoma: A large data from C hina

Purpose

To investigate the mechanisms of recurrent laryngeal nerve (RLN) injury during endoscopic thyroidectomy via breast approach (ET-BA) in patients with papillary thyroid carcinoma (PTC).

Methods

The records of 416 PTC patients who underwent ET-BA with intraoperative neural monitoring (IONM) from May 2015 to May 2021 in Beijing Friendship Hospital affiliated to Capital Medical University were retrospectively analyzed.

Results

All patients were women. Mean age was 37.80 (7.87) years. The ET-BA was performed in 416 patients. Overall incidence of RLN injury was 4.3% (18 patients). Injury was transient in 13 patients (3.1%) and permanent in five (1.2%). Macroscopic physical changes were apparent in the injured nerve in five patients (27.8%) and postoperative hoarseness or cough after drinking water were present in 11 (61.1%). Two RLN injuries occurred during nerve identification at the RLN laryngeal entry point into the surgical field, 15 during early nerve dissection somewhere between the first 0.5 and 2 cm of the nerve's course through the surgical field, and one occurred distal to 2 cm. The percentage of patients with separation, transection, traction and thermal mechanisms of injury was 27.8%, 22.2%, 22.2%, and 16.7%, respectively. The mechanism of injury was unknown in 11.1%.

Conclusions

RLN injury may still occur during ET-BA despite endoscopic magnification and early nerve identification even when IONM is used. Separation, transection, and traction injuries were the most frequent causes of injury.

Proving the Superiority of Intraoperative Recurrent Laryngeal Nerve Monitoring over Visualization Alone during Thyroidectomy

Vocal fold paralysis after thyroid surgery is still a dangerous complication that significantly reduces patients’ quality of life. Since the intraoperative neuromonitoring (IONM) technique has been introduced and standardized, the most frequently asked question is whether its use has significantly reduced the rate of RLN injury during thyroid surgery compared to visual identification alone (VA). The aim of this study was to attempt to prove the superiority of IONM over VA of the RLN during thyroid surgery in the prevention of vocal fold paralysis, taking into account risk factors for complications. The medical records of 711 patients (1265 recurrent laryngeal nerves at risk of injury) were analyzed retrospectively: in 257 patients/469 RLNs at risk, thyroid surgery was performed with IONM; in 454 patients/796 RLNs at risk, surgery was performed with VA. The statistical analysis showed that in the group of patients with IONM only one risk factor—the surgeon’s experience—proved statistically significant (OR = 3.27; p = 0.0478) regarding the overall risk of vocal fold palsy. In the group of patients where only visualization was used, 5 of the 12 factors analyzed were statistically significant: retrosternal goiter (OR = 2.23; p = 0.041); total thyroid volume (OR = 2.30; p = 0.0284); clinical diagnosis (OR = 2.5; p = 0.0669); gender (OR = 3.08; p = 0.0054) and risk stratification (OR = 3.30; p = 0.0041). In addition, the cumulative risk, taking into account the simultaneous influence of all 12 factors, was slightly higher in the group of patients in whom only VA was used during the procedure: OR = 1.78. This value was also considerably more statistically significant (p < 0.0001) than that obtained in the group of patients in whom IONM was used: OR = 1.73; p = 0.004. Conclusions: Risk factors for complications in thyroid surgery are not significant for any increase in the rate of vocal fold paralysis as long as surgery is performed with IONM, in contrast to thyroid surgery performed only with VA, thus proving the superiority of IONM over VA for safety.

The role of intraoperative neuromonitoring in preventing lesions of the spinal accessory nerve during functional neck dissection

Intraoperative neuromonitoring (IONM) in thyroid surgery offers a valid aid to the operator in identifying the recurrent laryngeal nerve and preserving its function. Recently, IONM has also been used in other surgeries, such as spinal accessory nerve dissection, during lymphectomy of the II, III, IV, and V laterocervical lymph nodes. The goal is the preservation of the spinal accessory nerve, whose macroscopic integrity does not always indicate its functionality. A further difficulty is the anatomical variability of its course at the cervical level. The aim of our study is to assess whether the use of the IONM helps to reduce the incidence of transient and permanent paralysis of the spinal accessory nerve, compared to "de visu" identification by the surgeon alone. In our case series, the use of the IONM reduced the incidence of transient paralysis, and no permanent paralysis was recorded. In addition, if the IONM registers a reduction in nerve potential, compared to the baseline value during surgery, it could indicate the need for early rehabilitation treatment, increasing the patients' chances of regaining function and reducing the costs of prolonged physiotherapy treatment.

Outcomes of Surgical Treatment for Graves' Disease: A Single-Center Experience of 216 Cases

BACKGROUND

The role of surgery in the treatment of Graves' disease (GD) needs to be revisited. The aims of the present retrospective study were to evaluate the outcomes of the current surgical strategy as a definitive treatment of GD at our center and to explore the clinical association between GD and thyroid cancer.

METHODS

A patient cohort of 216 cases from 2013 to 2020 was involved in this retrospective study. The data of the clinical characteristics and follow-up results were collected and analyzed.

RESULTS

There were 182 female and 34 male patients. The mean age was 43.9 ± 15.0 years old. The mean duration of GD reached 72.2 ± 92.7 months. Of the 216 cases, 211 had been treated with antithyroid drugs (ATDs) and hyperthyroidism had been completely controlled in 198 cases. A total (75%) or near-total (23.6%) thyroidectomy was performed. Intraoperative neural monitoring (IONM) was applied to 37 patients. The failure of ATD therapy (52.3%) was the most common surgical indication, followed by suspicion of a malignant nodule (45.8%). A total of 24 (11.1%) patients had hoarseness after the operation and 15 (6.9%) patients had transient vocal cord paralysis; 3 (1.4%) had this problem permanently. No bilateral RLN paralysis occurred. A total of 45 patients had hypoparathyroidism and 42 of them recovered within 6 months. Sex showed a correlation with hypoparathyroidism through a univariate analysis. A total of 2 (0.9%) patients underwent a reoperation because of hematomas. A total of 104 (48.1%) cases were diagnosed as thyroid cancer. In most cases (72.1%), the malignant nodules were microcarcinomas. A total of 38 patients had a central compartment node metastasis. A lateral lymph node metastasis occurred in 10 patients. Thyroid carcinomas were incidentally discovered in the specimens of 7 cases. The patients with concomitant thyroid cancer had a significant difference in body mass index, duration of GD, gland size, thyrotropin receptor antibodies and nodule(s) detected.

CONCLUSION

Surgical treatments for GD were effective, with a relatively low incidence of complications at this high-volume center. Concomitant thyroid cancer is one of the most important surgical indications for GD patients. Careful ultrasonic screening is necessary to exclude the presence of malignancies and to determine the therapeutic plan.

Comparative surgical outcomes of transoral endoscopic and robotic thyroidectomy for thyroid carcinoma: a propensity score-matched analysis

BACKGROUND

Surgical outcomes of patients with thyroid carcinoma who underwent transoral endoscopic thyroidectomy vestibular approach (TOETVA) versus transoral robotic thyroidectomy (TORT) were compared.

METHODS

Patients who underwent TOETVA or TORT between July 2016 and February 2022 were retrospectively analyzed. TOETVA and TORT groups were propensity score-matched (1:1) based on age, sex, body mass index, surgical extent, tumor size, and presence of thyroiditis.

RESULTS

A total of 185 patients underwent transoral thyroidectomy (142 TOETVA and 43 TORT). Final diagnoses consisted of 135 papillary and seven follicular thyroid carcinomas in the TOETVA group and 43 papillary thyroid carcinomas in the TORT group (p = 0.138). Mean operative time was shorter for the TOETVA group than the TORT group (106.3 vs. 158.9 min, p < 0.001), whereas mean hospital stay was longer for the TOETVA group than the TORT group (2.2 vs. 1.9 days, p = 0.031). After 1:1 propensity score matching, each group included 43 patients. Mean operative time was shorter in the TOETVA group than the TORT group (106.2 vs. 158.9 min, p < 0.001), whereas mean hospital stay was longer in the TOETVA group (2.3 vs. 1.9 days, p = 0.031). There was no significant difference in vocal cord palsy incidences between the groups (one transient, one permanent in the TOETVA group vs. none in the TORT group, p = 0.359). The learning curve was 71 cases for TOETVA and 25 cases for TORT.

CONCLUSION

TOETVA had shorter mean operative time, and TORT had shorter learning curve and shorter mean hospital stay. Surgeons should be familiar with the advantages and disadvantages of each procedure.

Review: Improving quality of life in patients with differentiated thyroid cancer

Well differentiated thyroid cancer is a common malignancy diagnosed in young patients. The prognosis tends to be excellent, so years of survivorship is expected with low risk disease. When making treatment decisions, physicians should consider long-term quality of life outcomes when guiding patients. The implications for treating indolent, slow growing tumors are immense and warrant careful consideration for the functioning years ahead. Surgery is the standard of care for most patients, however for a subset of patients, active surveillance is appropriate. For those wishing to treat their cancer in a more active way, novel remote access approaches have emerged to avoid a cervical incision. In the era of "doing less", options have further expanded to include minimally invasive approaches, such as radiofrequency ablation that avoids an incision, time off work, a general anesthetic, and the possibility of post-treatment hypothyroidism. In this narrative review, we examine the health related quality of life effects that surgery has on patients with thyroid cancer, including some of the newer innovations that have been developed to address patient concerns. We also review the impact that less aggressive treatment has on patient care and overall wellbeing in terms of active surveillance, reduced doses of radioactive iodine (RAI) treatment, or minimally invasive techniques such as radiofrequency ablation (RFA) for low risk thyroid disease.

Application of Intraoperative Neuromonitoring (IONM) of the Recurrent Laryngeal Nerve during Esophagectomy: A Systematic Review and Meta-Analysis

BACKGROUND

recurrent laryngeal nerve palsy (RLNP) is a common and severe complication of esophagectomy in esophageal cancer (EC). Several studies explored the application of intraoperative neuromonitoring (IONM) in esophagectomy to prevent RLNP. The purpose of this study was to conduct a systematic review and meta-analysis to evaluate the value of IONM in esophagectomy for EC.

METHODS

an electronic of the literature using Google Scholar, PubMed, Embase, and Web of Science (data up to October 2022) was conducted and screened to compare IONM-assisted and conventional non-IONM-assisted esophagectomy. RLNP, the number of mediastinal lymph nodes (LN) dissected, aspiration, pneumonia, chylothorax, anastomotic leakage, the number of total LN dissected, postoperative hospital stay and total operation time were evaluated using Review Manager 5.4.1.

RESULT

ten studies were ultimately included, with a total of 949 patients from one randomized controlled trial and nine retrospective case-control studies in the meta-analysis. The present study demonstrated that IONM reduced the incidence of RLNP(Odds Ratio (OR) 0.37, 95% Confidence Interval (CI) 0.26-0.52) and pneumonia (OR 0.58, 95%CI 0.41-0.82) and was associated with more mediastinal LN dissected (Weighted Mean Difference (WMD) 4.75, 95%CI 3.02-6.48) and total mediastinal LN dissected (WMD 5.47, 95%CI 0.39-10.56). In addition, IONM does not increase the incidence of aspiration (OR 0.4, 95%CI 0.07-2.51), chylothorax (OR 0.55, 95%CI 0.17-1.76), and anastomotic leakage (OR 0.78, 95%CI 0.48-1.27) and does not increase the total operative time (WMD -12.33, 95%CI -33.94-9.28) or postoperative hospital stay (WMD -2.07 95%CI -6.61-2.46) after esophagectomy.

CONCLUSION

IONM showed advantages for preventing RLNP and pneumonia and was associated with more mediastinal and total LN dissected in esophagectomy. IONM should be recommended for esophagectomy.

Impact of direct laryngoscopy vs. videolaryngoscopy on signal quality of recurrent laryngeal nerve monitoring in thyroid surgery: a randomised parallel group trial

In thyroid surgery, intra-operative neuromonitoring signals of the recurrent laryngeal nerve can be detected by surface electrodes on a tracheal tube positioned at the vocal fold level. The incidence of difficult tracheal intubation in patients undergoing thyroidectomy for nodular goitre ranges from 5.3% to 20.5%. The aim of this study was to compare videolaryngoscopy with conventional direct laryngoscopy as methods for proper placement of the surface electrode to prevent insufficient intra-operative nerve signal quality. In this prospective randomised trial, adult patients requiring tracheal intubation during thyroid surgery were randomly allocated to two groups of C-MAC^® (Macintosh style blade) videolaryngoscope or direct laryngoscopy using the Macintosh laryngoscope. Primary outcome was the incidence of insufficient signal electromyogram amplitude level (< 500 μV) after successful tracheal intubation. A total of 260 (130 per group) participants were analysed. An insufficient signal was more frequent with direct laryngoscopy (35/130, 27%), compared with C-MAC (12/130, 9%, p < 0.001). First-pass tracheal intubation success rate was lower with direct laryngoscopy (86/130 (66%)) compared with the C-MAC (125/130 (96%)) (p < 0.0001). Cormack and Lehane grade ≥ 3 was observed more frequently with direct laryngoscopy (16/130 (12%)), compared with the C-MAC (0/130, (0%)) (p < 0.0001). The results suggest that videolaryngoscopy has an impact on the quality of the initial intra-operative neuromonitoring signal in patients undergoing thyroid surgery, and this technique can provide optimised surface electrode positioning.

One hundred most-cited articles in head and neck surgery and analysis of female authorship

BACKGROUND

While female head and neck surgeons have made significant contributions to the field, women's achievements in scientific communication have traditionally been underreported.

METHODS

A search of high-impact journals in the field of head and neck surgery was performed in the Elsevier's Scopus database to identify the top 100 most-cited articles.

RESULTS

The top 100 most-cited articles (during the span of 1953 and 2016) had the highest total number of citations between 2005 and 2009. Women accounted for 36% of first authors and 25% of corresponding authors. Change in the relative number of first female authors in these top 100 articles did not increase significantly between 1950 and 2019.

CONCLUSION

The proportion of female first authors in head and neck surgery has not significantly increased over the past several decades, despite greater numbers of female trainees. Our findings support the need for additional research on female representation in head and neck surgery.

Usefulness of intraoperative nerve monitoring for giant type AB thymoma combined with an aberrant right subclavian artery: a case report

BACKGROUND

Abnormal tumor vascularization and escalating tumor size represent two major impediments that make cancer surgery impossible or complicated.

CASE PRESENTATION

Herein, we report the case of a giant thymoma (type AB) in a 58-year-old woman who presented with cough and yellow sputum. The thymoma grew extensively from the neck to the upper mediastinum. The patient exhibited an aberrant right subclavian artery and a non-recurrent inferior laryngeal nerve. Intraoperative nerve monitoring facilitated the identification and preservation of vital nerves spanning the neck and chest, including the non-recurrent inferior laryngeal nerve. Furthermore, the tumor was divided naturally along the constriction, and a good field of view was acquired to identify abnormal right subclavian arteries and nerves that ran deep in the tumor and surgical field. The tumor was safely removed without complications using intraoperative nerve monitoring, and the thymoma that grew extensively from the neck to the upper mediastinum and was associated with an aberrant right subclavian artery was resected.

CONCLUSION

Intraoperative nerve monitoring was helpful in identifying the non-recurrent inferior laryngeal nerve and left recurrent laryngeal nerve.