The Impact of Intraoperative Neuromonitoring (IONM) on Surgical Strategy in Bilateral Thyroid Diseases: Is it Worth the Effort?

Outcomes of Immediate Total Thyroidectomy in First-Side Loss of Neuromonitoring Signal

Importance

Use of intraoperative neuromonitoring (IONM) during thyroidectomy can nearly eliminate the risk of postoperative bilateral vocal cord palsy (VCP) by indicating staged surgery in cases of loss of signal (LOS) on the first side of planned total thyroidectomy. However, aborting planned total thyroidectomy may lead to persistence of symptoms, delay in adjuvant treatment, and patient inconvenience and distress. There are few data to guide a selective approach to total thyroidectomy in patients with first-side LOS.

Objective

To investigate outcomes of immediate bilateral surgery in patients undergoing total thyroidectomy with first-side LOS.

Design, Setting, and Participants

This cohort study was a retrospective review of outcomes for patients undergoing thyroidectomy between January 2016 and July 2023 at an academic tertiary referral center for thyroid surgery. Consecutive patients scheduled for total thyroidectomy using IONM were included. Exclusion criteria were preoperative VCP, deliberate sacrifice of recurrent laryngeal nerve (RLN), inadvertent RLN resection, and surgery performed without IONM.

Exposures

Total thyroidectomy performed using IONM.

Main Outcome Measures

Vocal mobility on first postoperative day as assessed by flexible laryngoscopy; secondary outcome measures included subjective voice assessment, other postoperative complications, and long-term vocal mobility.

Results

Among 400 patients undergoing planned total thyroidectomy (mean age, 50.5 years [range, 4-88 years]; 318 female [79.5%]), 51 (12.8%) had first-side LOS, of whom 37 (9.3%) had persistent LOS. Twenty-nine patients (56% of procedures with first-side LOS, including 18 with persistent LOS) proceeded to immediate total thyroidectomy. Postoperatively, 16 patients (55% of patients undergoing total thyroidectomy following first-side LOS, including 14 of 18 with persistent LOS) had impaired vocal mobility. One patient had bilateral VCP that did not require tracheostomy, and 2 had postoperative hypoparathyroidism. Of those whose surgery was aborted after first-side LOS, 8 of 22 (36%) underwent completion thyroidectomy at a later stage. In those undergoing completion thyroidectomy, 2 of 8 (25%) had temporary VCP after the second surgery, 2 (25%) had permanent hypoparathyroidism, and 1 (12.5%) developed inoperable cancer. Postoperative VCP was fully reversible in all but 1 patient.

Conclusion and Relevance

Among patients planned for total thyroidectomy who develop first-side LOS, immediate total thyroidectomy may be considered among those who have pressing reasons for same, and where surgical difficulties might be anticipated in a secondary surgery.

Management of Bilateral Vocal Fold Paralysis: A Systematic Review

OBJECTIVE

To review the current literature about epidemiology, etiologies and surgical management of bilateral vocal fold paralysis (BVFP).

DATA SOURCES

PubMED, Scopus, and Cochrane Library.

REVIEW METHODS

A systematic review of the literature on epidemiology, etiologies, and management of adult patients with BVFP was conducted through preferred reporting items for systematic reviews and meta-analyses statements by 2 investigators.

RESULTS

Of the 360 identified papers, 245 were screened, and of these 55 were considered for review. The majority (76.6%) of BVFP cases are iatrogenic. BVFP requires immediate tracheotomy in 36.2% of cases. Laterofixation of the vocal fold was described in 9 studies and is a cost-effective alternative procedure to tracheotomy while awaiting potential recovery. Unilateral and bilateral posterior transverse cordotomy outcomes were reported in 9 and 7 studies, respectively. Both approaches are associated with a 95.1% decannulation rate, adequate airway volume, but voice quality worsening. Unilateral/bilateral partial arytenoidectomy data were described in 4 studies, which reported lower decannulation rate (83%) and better voice quality outcome than cordotomy. Revision rates and complications vary across studies, with complications mainly involving edema, granuloma, fibrosis, and scarring. Selective posterior cricoarytenoid reinnervation is being performed by more surgeons and should be a promising addition to the BVFP surgical armamentarium.

CONCLUSION

Depending on techniques, the management of BVFP may be associated with several degrees of airway improvements while worsened or unchanged voice quality. The heterogeneity between studies, the lack of large-cohort controlled randomized studies and the confusion with posterior glottic stenosis limit the draw of clear conclusion about the superiority of some techniques over others.

Advantages of Intraoperative Neuromonitoring Over Direct Visualization of the Recurrent Laryngeal Nerve During Thyroidectomy

BACKGROUND

The well-recognized risk of injury to the recurrent laryngeal nerve (RLN) during thyroidectomy has instigated various preventive measures. One such measure involves directly visualizing the RLN, but this is not always feasible in practice. A more recent approach involves using intraoperative neuromonitoring to identify and preserve the RLN. This study aims to evaluate the effectiveness of intraoperative neuromonitoring compared to single visualization of the RLN in averting nerve injury.

METHODS

We conducted a retrospective, observational, and descriptive study on a cohort of 218 patients. A Chi-square test was employed to determine the influence of intraoperative neuromonitoring on the incidence of nerve injury, with P < 0.05 considered statistically significant. We used Jamovi software version 2.3.18 to analyze the data.

RESULTS

Of the 218 patients, intraoperative neuromonitoring was used in 150 (68.8%) cases; none of which resulted in nerve injury. Conversely, 68 (31.2%) patients underwent surgery without the use of neuromonitoring, with two (2.9%) patients in this group experiencing nerve injury (p=0.037). In comparison, the risk of nerve injury was 0% in the group monitored intraoperatively and 2.94% in the group that did not undergo intraoperatively neuromonitoring. Further, the relative risk of complications was 0.66% in patients operated with neuromonitoring, while it was 5.88% in the group operated without neuromonitoring, thus demonstrating a clinically significant protective against vasculonervous complications.

CONCLUSION

The results advocate for the use of intraoperative neuromonitoring, whenever available, as it is a safe method for significantly decreasing the incidence of RLN injury during thyroidectomy compared with only visualization.

Intraoperative Neuromonitoring and Optical Magnification in the Prevention of Recurrent Laryngeal Nerve Injuries during Total Thyroidectomy

Background and Objectives: Recurrent laryngeal nerve (RLN) paralysis is a fearful complication during thyroidectomy. Intraoperative neuromonitoring (IONM) and optical magnification (OM) facilitate RLN identification and dissection. The purpose of our study was to evaluate the influence of the two techniques on the incidence of RLN paralysis and determine correlations regarding common outcomes in thyroid surgery. Materials and Methods: Two equally sized groups of 50 patients who underwent total thyroidectomies were examined. In the first group (OM), only surgical binocular loupes (2.5×−4.5×) were used during surgery, while in the second group (IONM), the intermittent NIM was applied. Results: Both the operative time and the length of hospitalization were shorter in the OM group than in the IONM group (median 80 versus 100 min and median 2 versus 4 days, respectively) (p < 0.05). The male patients were found to have a five-fold higher risk of developing transient dysphonia than the females (adjusted OR 5.19, 95% IC 0.99−27.18, p = 0.05). The OM group reported a four-fold higher risk of developing transient hypocalcemia than the IONM group (OR 3.78, adjusted OR 4.11, p = 0.01). Despite two cases of temporary bilateral RLN paralysis in the IONM group versus none in the OM group, no statistically significant difference was found (p > 0.05). No permanent RLN paralysis or hypoparathyroidism have been reported. Conclusions: Despite some limitations, our study is the first to compare the use of IONM with OM alone in the prevention of RLN injuries. The risk of recurrent complications remains comparable and both techniques can be considered valid instruments, especially if applied simultaneously by surgeons.

A large-scale study of patients with preoperative vocal cord paralysis associated with thyroid disease and related clinicopathological features

BACKGROUND

The performance of thyroidectomies has been increasing over the last decade due to the growing prevalence of thyroid diseases. The purpose of this study was to investigate the clinical significance of preoperative vocal cord paralysis (VCP) associated with thyroid disease and other incidences of malignant or benign lesions, as well as different thyroid pathological features. Additionally, the epidemiological changes of thyroid diseases with preoperative VCP were investigated.

METHODS

Ninety-nine out of 12,530 patients with preoperative VCP who had undergone thyroid surgery for various diseases in the Zhejiang Cancer Hospital from January 2007 to December 2015 were identified. Their clinicopathological data was recorded and case distributions from different years and intraoperative recurrent laryngeal nerve statuses were retrospectively analyzed.

RESULTS

The incidence of preoperative VCP in 2007 was reported to be 1.53% (9/590) and had decreased to 0.53% (12/2,247) by 2015 (P < 0.05). Among the 99 patients with preoperative VCP, 81 had malignancies (81.82%), while 18 (18.18%) had benign thyroid diseases. The incidences of preoperative VCP in malignant and benign diseases were 1.13% (81/7,159) and 0.35% (18/5,371), respectively (P < 0.05). There were only 5 (0.04%, 5/12,530) cases of papillary thyroid microcarcinoma with preoperative VCP. There was no statistical difference between the incidence of preoperative hoarseness in malignant 69.14% (56/81) and benign diseases 61.11% (11/18) with preoperative VCP.

CONCLUSIONS

The preoperative VCP incidence rate had gradually decreased with an increased proportion of papillary thyroid cancer. Preoperative voice symptoms do not necessarily suggest a malignancy. Selective rather than routine preoperative laryngoscopic examinations should be performed on papillary thyroid microcarcinomas. The probability of preoperative VCP in malignancy was significantly higher than in benign lesions.

Seeing Is Not Believing: Intraoperative Nerve Monitoring (IONM) in the Thyroid Surgery

Ensuring the integrity of the recurrent laryngeal nerve (RLN), the external branch of superior laryngeal nerve (EBSLN) and preservation of normal voice are the prime 'functional' goals of thyroid surgery. More in-depth knowledge of neuronal mechanisms has revealed that anatomical integrity does not always translate into functional integrity. Despite meticulous dissection, neural injuries are not always predictable or visually evident. Intraoperative nerve monitoring (IONM) is designed to aid in nerve identification and early detection of functional impairment. With the evolution of technique, intermittent monitoring has given way to continuous-IONM. Over the years, IONM gathered both support and flak. Despite numerous randomised studies, systematic reviews, and meta-analyses, there still prevails a state of clinical equipoise concerning the utility of IONM and its cost-effectiveness. This article inspects the true usefulness of IONM, elaborates on the optimal way to practice it, and presents a critical literature review.

The value of intraoperative nerve monitoring against recurrent laryngeal nerve injury in thyroid reoperations

Reoperative thyroidectomy is challenging for surgeons because of the higher incidence of recurrent laryngeal nerve (RLN) palsy. RLN identification is the gold standard during thyroidectomy; however, it is sometimes difficult to perform thyroid reoperations. In recent years, intraoperative nerve monitoring (IONM) has gained increased acceptance, and the use of IONM can be a valuable adjunct to visual identification. The aim of this study was to evaluate the value of IONM during thyroid reoperation.A total of 109 patients who met our criteria at the Affiliated Hospital of Hangzhou Normal University from January 2010 to June 2020 were retrospectively analyzed and divided into the IONM group and the visualization-alone group (VA group) according to whether neuromonitoring was used during the operation. The patients' characteristics, perioperative data, and intraoperative information including the RLN identification, time of RLNs confirmation, operative time, intraoperative blood loss, and the rate of RLN injury were collected.Sixty-five procedures (94 RLNs at risk) were performed in the IONM group, whereas 44 (65 RLNs at risk) were in the VA group. The rate of RLN identification was 96.8% in the IONM group and 75.4% in the VA group (P < .05). The incidence of RLN injury was 5.3% in the IONM group and 13.8% in the VA group (P > .05). The incidence of surgeon-related RLN injury rate was 0% in the IONM group compared to 7.7% in the VA group (P < .05), but the tumor-related or scar-related RLN injury rate between the 2 groups were not significantly different (4.3% vs 3.1%, 1.1% vs 3.1%, P > .05).IONM in thyroid reoperation was helpful in improving the RLN identification rate and reducing the surgeon-related RLN injury rate, but was ineffective in reducing the tumor-related and scar-related RLN injury rate. In the future, multicenter prospective studies with large sample sizes may be needed to further assess the role of IONM in thyroid reoperations.

Effectiveness of early administration of a single dose of steroids and escin after loss of signal on electromyographic signal recovery during neuromonitored thyroidectomy

BACKGROUND

The aim of this study was to evaluate the effect of a single early administration of dexamethasone and escin after loss of signal (LOS) during a neuromonitored total thyroidectomy.

METHODS

A retrospective analysis of results concerning consecutive patients undergoing total thyroidectomy was performed. Patients included in the study were divided into two groups: Group 1 for which a "wait and see" strategy was used; Group 2, receiving dexamethasone and escin immediately after LOS detection.

RESULTS

Overall 37 patients were included in Group 1 and 35 in Group 2. LOS recovery occurring in 29.7% of cases (n. 11) versus 65.7% (n. 23) respectively (p < 0.001). Postoperative fibrolayngoscopy for patients without LOS recovery showed normal cord function in 4 out of 26 cases (15.4%) in Group 1 and in 7 out of 12 (58.3%) in Group 2 (p < 0.001).

CONCLUSIONS

The early administration of dexamethasone and escin after LOS detection may achieve greater EMG signal recovery than a "wait and see" strategy.

Value of Neurostimulation Plus Laryngeal Palpation to Predict Postoperative Vocal Fold Motility

BACKGROUND

The aim of this study was to evaluate the reliability of intraoperative neuromonitoring through recurrent laryngeal nerve stimulation and simultaneous laryngeal palpation (NSLP) in predicting postoperative vocal cord palsy and in providing useful information in the decision to perform a staged surgery in initially planned total thyroidectomy.

MATERIALS AND METHODS

A retrospective review was performed involving 552 patients for whom a total thyroidectomy was planned. In all patients, preoperative and postoperative laryngoscopy was performed. The incidence of vocal cord palsy was calculated on 1104 nerves at risk.

RESULTS

Sensitivity and specificity of NSLP were 0.9411 and 0.9925 respectively. The positive predictive value was 0.7804, the negative predictive value was 0.9981, the false positive rate was 0.8%. In 41 patients (7.4%) the initial surgical strategy was changed into a staged procedure. Nine patients (21.9%) were false positive, 32 patients (78.1%) were true positive. Finally, a two-stage thyroidectomy was performed in 27 of 41 patients.

CONCLUSIONS

High sensitivity and specificity confirm the validity of NSLP in predicting postoperative vocal cord palsy and in driving a possible staged thyroidectomy, both in benign thyroid disease and in differentiated thyroid carcinoma.

Anatomical, Functional, and Dynamic Evidences Obtained by Intraoperative Neuromonitoring Improving the Standards of Thyroidectomy

The use of intraoperative neuromonitoring (IONM) is getting more common in thyroidectomy. The data obtained by the usage of IONM regarding the laryngeal nerves’ anatomy and function have provided important contributions for improving the standards of the thyroidectomy. These evidences obtained through IONM increase the rate of detection and visual identification of recurrent laryngeal nerve (RLN) as well as the detection rate of extralaryngeal branches which are the most common anatomic variations of RLN. IONM helps early identification and preservation of the non-recurrent laryngeal nerve. Crucial knowledge has been acquired regarding the complex innervation pattern of the larynx. Extralaryngeal branches of the RLN may contribute to the motor innervation of the cricothyroid muscle (CTM). Anterior branch of the extralaryngeal branching RLN has always motor function and gives motor branches both to the abductor and adductor muscles. In addition, up to 18% of posterior branches may have adductor and/or abductor motor fibers. In 70–80% of cases, external branch of superior laryngeal nerve (EBSLN) provides motor innervation to the anterior 1/3 of the thyroarytenoid muscle which is the main adductor of the vocal cord through the human communicating nerve. Furthermore, approximately 1/3 of the cases, EBSLN may contribute to the innervation of posterior cricoarytenoid muscle which is the main abductor of ipsilateral vocal cord. RLN and/or EBSLN together with pharyngeal plexus usually contribute to the motor innervation of cricopharyngeal muscle that is the main component of upper esophageal sphincter. Traction trauma is the most common reason of RLN injuries and constitutes of 67–93% of cases. More than 50% of EBSLN injuries are caused by nerve transection. A specific point of injury on RLN can be detected in Type 1 (segmental) injury, however, Type 2 (global) injury is the loss of signal (LOS) throughout ipsilateral vagus-RLN axis and there is no electrophysiologically detectable point of injury. Vocal cord paralysis (VCP) develops in 70–80% of cases when LOS persists or incomplete recovery of signal occurs after waiting for 20 min. In case of complete recovery of signal, VCP is not expected. VCP is temporary in patients with incomplete recovery of signal and permanent VCP is not anticipated. Visual changes may be seen in only 15% of RLN injuries, on the other hand, IONM detects 100% of RLN injuries. IONM can prevent bilateral VCP. Continuous IONM (C-IONM) is a method in which functional integrity of vagus-RLN axis is evaluated in real time and C-IONM is superior to intermittent IONM (I-IONM). During upper pole dissection, IONM makes significant contributions to the visual and functional identification of EBSLN. Routine use of IONM may minimalize the risk of nerve injury. Reduction of amplitude more than 50% on CTM is related with poor voice outcome.

Intraoperative recurrent laryngeal nerve monitoring using endotracheal electromyography during parathyroidectomy for secondary hyperparathyroidism

Objective

To investigate the factors associated with adherence of an enlarged parathyroid gland to the recurrent laryngeal nerve (RLN) and the effectiveness of intraoperative neural monitoring (IONM).

Methods

This single-center retrospective study involved samples from 197 consecutive patients (394 RLNs; 733 parathyroid glands) who underwent parathyroidectomy and transcervical thymectomy between September 2010 and December 2014. The presence of parathyroid gland adhesion to the RLN and the clinical characteristics of patients with and without nerve adhesion were recorded. All patients underwent intraoperative monitoring of the electromyographic responses of the vocal cords using the endotracheal NIM-Response 3.0 system. The patients’ postoperative clinical outcomes were recorded.

Results

Parathyroid gland adhesion to the RLN was significantly associated with maximum gland diameter (>15 mm), weight (>500 mg), and the presence of nodular hyperplasia. IONM demonstrated a sensitivity of 97.8%, specificity of 43.5%, and accuracy of 94.7% for detecting nerve damage. Parathyroid gland adhesion to 17 RLNs occurred in 3 cases (17.6%) of vocal cord paralysis, whereas the 377 glands without nerve adhesion resulted in vocal cord paralysis in 20 cases (5.3%).

Conclusion

Our findings demonstrated the effectiveness of IONM using endotracheal electromyography in patients who underwent parathyroidectomy for secondary hyperparathyroidism.

Intraoperative neuromonitoring (IONM) in thyroidectomy for carcinoma in an high volume academic Hospital

BACKGROUND

The diagnosis of thyroid carcinoma has changed in last decades, as the surgical technique during thyroidectomy (endoscopic surgery, robotic surgery, new energy device, intraoperative neuromonitoring).

METHODS

We analyzed patients undergone to thyroidectomy or lobectomy for thyroid carcinoma from January 2010 to December 2019 at the General Surgery Unit of the Hospital - University of Parma. We divided patients into two groups, based on the use or not of IONM.

RESULTS

We analyzed data about 638 patients, 486 (76.2%) female and 152 (23.8%) male, with a mean age of 51.8 years. Totally, 574 patients underwent total thyroidectomy and lymphadenectomy was performed in 39 patients. The lobectomy rate was higher in interventions with neuromonitoring (13.93%) than in those without IONM (3.06%). Considering the incidence of postoperative complications and the presence of infiltration of perithyroid tissues or thyroiditis or lymph node metastasis at the histological report, a statistically significant percentage of dysphonia and paraesthesia was recorded only in patients with infiltration of perithyroid tissues (p <0.0001). There was no significant difference in postoperative blood calcium values. The use of intraoperative neuromonitoring has not significantly changed the incidence of postoperative complication.

CONCLUSIONS

Our study did not show a protective impact of the use of intraoperative neuromonitoring during thyroidectomy on the incidence of postoperative complications but confirmed that it increases the surgeon's feel safety during surgery and facilitates the identification of any undetected nerve lesion with visually intact nerve, inducing the interruption of the thyroidectomy after lobectomy alone, reducing the risk of bilateral recurrent paralysis.

Experience with the use of intraoperative continuous nerve monitoring in video-assisted neck surgery and external cervical incisions

OBJECTIVES

Recurrent laryngeal nerve (RLN) injury is one of the severe complications in thyroid surgery. Therefore, intraoperative nerve monitoring (IONM) has been widely used to identify the RLN and confirm its integrity. Recently, the usefulness of continuous IONM (CIONM) with automatic, periodic stimulation to the vagus nerve during thyroid surgery was reported. This study aimed to report our experience with minimally invasive video-assisted endoscopic endocrine neck surgery (VANS), during which, CIONM was successfully applied for the first time.

METHODS

Consecutive patients who underwent thyroid surgery with CIONM, performed in our department using either external neck incision surgery or VANS between July 2017 and June 2019, were retrospectively analyzed.

RESULTS

A total of 22 patients who underwent thyroid surgery with neck incision (14 cases; 7 men and 7 women; age, 21-75 years [mean, 52 years]) or VANS (8 cases; 8 women, age, 20-61 years [mean, 41 years]) were enrolled in this study. The addition of CIONM in VANS prolonged the operation's duration by approximately 30 minutes as the endoscopic surgery was technically more difficult. No intra- and postoperative incidence of transient or permanent RLN palsy was observed in any patient, except for three patients who underwent external neck incision surgery in whom combined resection was unavoidable due to tumor invasion of the RLN.

CONCLUSION

We reported the first successful application of CIONM during thyroidectomy using VANS. Future clinical trials should clarify the benefits of CIONM when compared to intermittent IONM in VANS.

LEVEL OF EVIDENCE

5.

Development and validation of the nomogram for predicting preoperative vocal cord palsy in thyroid cancer patients

Background

Low incidence of preoperative vocal cord palsy (VCP) promotes a diagnosis model to eliminate patients without the necessity of preoperative laryngoscopy assessments, avoiding medical costs and discomfort. However, previous studies lacked a comprehensive strategy and external validation data to effectively detect VCP in thyroid cancer patients. This study aimed to develop a VCP scoring system that could calculate cumulative VCP risks and determine preoperative laryngeal examinations based on the clinical characteristics of VCP patients from the Union Hospital, Tongji Medical College of Huazhong University of Science and Technology.

Methods

A retrospective study recruited 5,354 thyroid cancer patients was performed. Preoperative VCP incidence was recorded, and a prediction table was constructed using independent, significant risk factors for preoperative VCP. The visualized nomogram, including five parameters, was proportionally assigned 0 to 100 points. Finally, the diagnostic performance was confirmed by verifying the nomogram in the internal and external cohort.

Results

The incidence of preoperative VCP by preoperative laryngoscopy assessment was 1.57%. Age at diagnosis (OR: 1.04; P=0.006), history of neck surgery (OR: 11.57; P<0.001), voice symptoms (OR: 32.75; P<0.001), large nodule diameter (OR: 1.04; P<0.001) and suspicious neck lymph nodes (OR: 3.25; P<0.001) were identified as independent risk factors. The nomogram was proven to be acceptable discrimination in internal and external sets, and the cut-off value was 94.7.

Conclusions

We identified clinical risk factors related to preoperative VCP and established a nomogram for VCP clinical discrimination with an excellent performance in the external cohort.

Analyzing the ATA statement on outpatient thyroidectomy using the NSQIP database

INTRODUCTION

The aim of this study is to examine the outcomes of outpatient thyroidectomy per the American Thyroid Association (ATA) statement on this procedure using the American College of Surgeons National Surgical Quality Improvement Project (NSQIP) database.

METHODS

A retrospective study using NSQIP database (2016 2017) comparing outpatient (OP) and inpatient (IP) thyroidectomies based on the ATA statement.

RESULTS

There were 382 inpatient and 628 outpatient thyroidectomies. A vessel sealing device and intraoperative nerve monitoring were more commonly used in OP group. Drain use was less common in OP group. There was no difference in the rate of recurrent laryngeal nerve injury, neck hematoma, or postoperative hypocalcemia within 30 days after surgery. IP group had a higher rate of readmissions (3.4% vs 1.8%, p = 0.004). Logistic regression showed OP surgery was associated with a lower risk of readmission OR 0.38 (CI 0.15-0.97; p = 0.04).

CONCLUSION

The ATA criteria can be used to identify good candidates for outpatient thyroidectomy.

Medical Malpractice Trends in Thyroidectomies among General Surgeons and Otolaryngologists

Objectives

This study aims to examine litigation trends with thyroidectomies in the United States from 1984 to 2018.

Methods

We used the Westlaw legal database to collect data on the defendant, plaintiff, case demographics, alleged reasons for malpractice, additional complications, and case outcomes.

Results

The most common reason for litigation was vocal cord paralysis (51%, n = 28), with the majority ruling in favor of the defendant (64%, P = .042). Of those, 43% of cases (n = 12) were due to unilateral recurrent laryngeal nerve (RLN) injury, and 39% (n = 11) were due to bilateral RLN injury. Of the claims due to vocal cord paralysis that resulted in indemnity payment (36%), the majority included additional damages, such as lack of informed consent (30%) or subsequent damages from permanent tracheostomy (40%), which is usually a result of bilateral nerve paralysis.

Conclusion

RLN injury was the most common complication leading to trial, with most cases ruling in favor of the defense. However, most verdicts that favored the plaintiff or those that settled were due to subsequent damages from bilateral nerve paralysis, such as permanent tracheostomy. We encourage surgeons to consider a staged procedure in high-risk cases or cases with signal loss. There needs to be a bigger emphasis on informed consent in the training of surgeons. Surgeons should educate patients at high risk on potential surgical complications that may drastically affect their quality of life.

Intraoperative Neuromonitoring in Thyroid Surgery: An Efficient Tool to Avoid Bilateral Vocal Cord Palsy

OBJECTIVES

This study aimed to analyze the effects of intraoperative neuromonitoring (IONM) on the prevalence of vocal cord palsy (VCP) in thyroid surgery.

METHODS

Data from 493 patients (839 nerves at risk [NAR]) who underwent thyroid surgery between July 2014 and May 2016 were retrospectively evaluated. The patients were divided into 2 groups: Group 1 (G1) consisted of patients who underwent surgery without IONM, whereas group 2 (G2) consisted of patients who underwent surgery with IONM. The surgical techniques were identical, and experienced surgeons performed the procedures in both groups. Intraoperative neuromonitoring was performed in compliance with the International Neural Monitoring Guidelines.

RESULTS

In total, 211 patients (170 female, 41 male) with 360 NAR were included in G1, and 282 patients (220 female, 62 male) with 479 NAR were included in G2. The number of VCP per NAR in G1 and G2 was 33 (9.2%) and 27 (5.6%), respectively (P = .005). The number of transient VCP per NAR in G1 and G2 was 27 (7.5%) and 23 (4.8%; P = .230), respectively. The number of permanent VCP per NAR in G1 and G2 was 6 (1.7%) and 4 (0.8%; P = .341), respectively. Bilateral VCP was detected in 4 (2.7%) patients in G1, whereas there was no patient with bilateral VCP in G2 (P = .033).

CONCLUSIONS

Intraoperative neuromonitoring may decrease the incidence of total VCP and prevent the development of bilateral VCP, which has unfavorable results for both patients and health-care professionals.

Modern surgery for advanced thyroid cancer: a tailored approach

Surgical treatment of advanced thyroid malignancy can be morbid, compromising normal functions of the upper aerodigestive tract. There is a paucity of guidelines dedicated to the management of advanced disease. In fact, there is not even a uniform definition for advanced thyroid cancer currently. The presence of local invasion, bulky cervical nodes, distant metastases or recurrent disease should prompt careful preoperative evaluation and planning. Surgical strategy should evolve from multidisciplinary discussion that integrates individual disease characteristics and patient preference. Intraoperative neuromonitoring has important applications in surgery for advanced disease and should be used to guide surgical strategy and intraoperative decision-making. Recent paradigm shifts, including staged surgery and use of neoadjuvant targeted therapy hold potential for decreasing surgical morbidity and improving clinical outcomes. Modern surgical planning provides optimal treatment for each patient through a tailored approach based on exact extent and type of disease as well as incorporating appreciation of surgical complications, patient preferences and intraoperative findings.

Routine Preoperative Laryngoscopy for Thyroid Surgery Is Not Necessary Without Risk Factors

Background: Routine preoperative vocal cord (VC) assessment with laryngoscopy in patients undergoing thyroidectomy allows clear documentation of baseline VC function, aids in surgical planning in patients with palsies, and facilitates interpretation of intraoperative neuromonitoring (IONM) findings. We aimed to determine the incidence of preoperative vocal cord palsy (VCP); to evaluate the associated risk factors for preoperative VCP; and to calculate the cost-savings potential of implementing a selective approach. Methods: Patients with a pre-thyroidectomy VC assessment by fiberoptic laryngoscopy were retrospectively recruited from the Monash University Endocrine Surgery Unit database from 2000 to 2018. Cases with preoperative VCP were reviewed for potential contributing factors and compared with a non-palsy cohort. Results: Of the 5987 patients who had preoperative laryngoscopy, VCP was documented in 41 (0.68%) patients. Four clinical parameters were found to be potential indicators of VCP, including: age (p < 0.001), nodule ≥3.5 cm recorded on ultrasound imaging (p = 0.01), presence of voice symptoms (p < 0.001), and previous neck surgery (p < 0.001). Malignant cytology (p = 0.5) and exposure to head and neck irradiation were not different between the groups. Utilizing these risk factors, 2354 (39%) patients had at least one feature that may raise suspicion for preoperative VCP. By performing preoperative laryngoscopy only on this subset of patients, the potential cost savings exceeds 400 Australian Dollars per patient. Conclusions: Using this large dataset, we have established that a VCP is rare in the absence of a large nodule, hoarseness, or previous neck surgery. Therefore, in the era of IONM, we support a selective approach to preoperative laryngoscopy by using the aforementioned criteria.

Surgical management of the compromised recurrent laryngeal nerve in thyroid cancer

Surgical management of thyroid cancer requires careful consideration of the recurrent laryngeal nerve and its impact on glottic function. Management of the compromised recurrent laryngeal nerve is a complex task, requiring synthesis of multiple elements. The surgeon must have an appreciation for preoperative recurrent laryngeal nerve function, intraoperative anatomic and electromyographic information, disease characteristics, and relevant patient factors. Preoperative clinical evaluation including preoperative laryngoscopy and assessment of recurrent laryngeal nerve risk is essential to formulating a surgical plan and providing appropriate patient counseling. Intraoperative neuromonitoring information has significant implications for surgical management of the injured or invaded recurrent laryngeal nerve and informs strategy with respect to staging of bilateral surgery. Disease characteristics and patient-related factors, including patient preference, must be considered with intraoperative decision-making. Multidisciplinary discussion and patient communication are essential for effective management and successful surgical outcome.

Impact of continuous intraoperative vagus stimulation on intraoperative decision making in favor of or against bilateral surgery in benign goiter

The advent of continuous vagus stimulation (CVS), eliminating lag time between nerve preparation with potential trauma and stimulation, has transformed the intraoperative surgical strategy in thyroid surgery. Continuous intraoperative nerve monitoring empowers the surgeon to be optimally aware of traction-related injury to the recurrent laryngeal nerve (RLN). Electromyographic precursor lesions, called combined events, prompt surgeons to cease harmful surgical maneuvers and release the nerve before damage to the nerve is established. Complete RLN recovery, defined as restitution of the nerve amplitude to ≥50% of baseline, assures the surgeon that it is safe to pursue completion surgery of the contralateral side in one procedure. If this restitution is incomplete or absent (<50% of amplitude baseline) immediate vocal cord paralysis is likely and it is advisable to delay completion surgery until the nerve has fully recovered. This review summarizes the tremendous progress made in this dynamic field, delineating the extent to which CVS has changed the landscape: tailoring intraoperative decision making to determine the safest course of action for patients with benign goiter.

Intraoperative nerve monitoring during thyroidectomy: evaluation of signal loss, prognostic value and surgical strategy

INTRODUCTION

Intraoperative neural monitoring of the recurrent laryngeal nerve has been widely used to avoid nerve injury during thyroidectomy. We discuss the results of the change in surgical strategy after unilateral signal loss surgeries using intermittent intraoperative neural monitoring in a high-volume referral centre.

MATERIALS AND METHODS

Details of consecutive patients who underwent thyroidectomy with intermittent intraoperative neural monitoring between January 2014 and December 2017 were prospectively recorded and retrospectively reviewed. Loss of signal was defined as recurrent laryngeal nerve amplitude level lower than 100 μV during surgery. The rate of loss of signal and change in surgical strategy during the operation were evaluated.

RESULTS

Loss of signal was detected in 25 (5.4%) of 456 patients for whom intermittent intraoperative neural monitoring was performed. Four patients had anatomic nerve disruption and surgery was completed by an experienced endocrine surgeon making use of intraoperative neural monitoring with continuous vagal stimulation. Staged thyroidectomy was performed on 16 patients with unilateral loss of signal in whom the nerves were intact visually. Postoperative vocal cord paralysis was encountered in 18 of 21 (85.7%) patients with loss of signal, and 16 of 18 (88.8%) were improved during the follow-up period. Patients' voices were subjectively normal to the surgeon postoperatively in 9 of 21 (42.8%) patients who were found to have loss of signal with intact nerves.

CONCLUSIONS

Intraoperative neural monitoring can be used safely in thyroid surgery to avoid recurrent laryngeal nerve injury. It enables the surgeon to diagnose recurrent laryngeal nerve injury intraoperatively to estimate the postoperative nerve function and to modify the surgical strategy to avoid bilateral vocal cord paralysis.

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

Introduction

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

Aim

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

Material and methods

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

Results

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

Conclusions

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

Intraoperative intermittent neuromonitoring of inferior laryngeal nerve and staged thyroidectomy: our experience

PURPOSE

To evaluate the reliability of intermittent intraoperative neuromonitoring (I-IONM) through recurrent laryngeal nerve (RLN) stimulation and laryngeal palpation in predicting postoperative vocal cord palsy and to examine the reliability of this technique in providing useful information in the decision to perform a staged surgery in initially planned total thyroidectomy.

METHODS

This was a retrospective cohort study of patients who underwent thyroid surgery at the ENT Department of the University of Bologna from January 2014 to June 2017. In all cases, preoperative and postoperative laryngoscopy was performed. All surgeries were conducted with I-IONM and RLN simultaneous laryngeal palpation (NSLP) to detect contraction (laryngeal twitch) of the posterior crico-arytenoid muscle. The incidence of vocal cord palsy was calculated for nerves at risk. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were calculated with a confidence interval determined at 95% level.

RESULTS

Seven hundred and sixteen patients were enrolled in the study. The incidence of vocal cord palsy was 3.16%. Specificity of I-IONM in predicting vocal cord paralysis was 99.1% and sensitivity was 90%. The NPV was 99.7% and PPV 78.3%. Two-stage thyroidectomy (ST) was performed in 22 cases (22/570: 3.85%). Six patients (27.3%) were false positive and 16 true positive (72.7%) at I-IONM.

CONCLUSION

High sensitivity and specificity values confirm the validity of I-IONM with NSLP in predicting postoperative normal vocal cord function. Our results confirm that I-IONM may safely guide an ST overall in benign thyroid diseases and in low-grade malignancies.

Usefulness of intraoperative neuromonitoring for preservation of an extralaryngeal bifurcation of the recurrent laryngeal nerve: A case report

•

Recurrent laryngeal nerve injury is a major complication of thyroid surgery.

•

Use of an electromyography endotracheal tube can prevent this injury.

•

We describe a case of extralaryngeal bifurcation of the recurrent laryngeal nerve.

•

Intraoperative neuromonitoring could identify and preserve this bifurcation.

Introduction: Recurrent laryngeal nerve injury is a major complication of thyroid surgery. An endotracheal tube with electromyography electrodes attached to it was recently developed for intraoperative neuromonitoring during thyroid surgery. Here we describe the successful identification and preservation of an extralaryngeal bifurcation of the recurrent laryngeal nerve by intraoperative neuromonitoring in a patient undergoing thyroid surgery.

Presentation of case: A 56-year-old woman presented for evaluation of a neck swelling found during a medical examination. Computed tomography (CT) revealed a tumor with a 5-cm diameter in the left thyroid lobe. Fine needle aspiration cytology revealed a Bethesda category III finding. Left thyroid lobe resection was scheduled. During surgery, the left recurrent laryngeal nerve was found to be adhered to the tumor. Careful exploration and intraoperative neuromonitoring allowed us to identify and preserve an extralaryngeal bifurcation of the recurrent laryngeal nerve.

Discussion: The recurrent laryngeal nerve can demonstrate various anomalies and bifurcations. Failure to notice and correctly identify extralaryngeal bifurcation leads to recurrent laryngeal nerve injury. Motor branch injury has a particularly large effect. Intraoperative neuromonitoring has been reported to be useful for identifying and preserving the recurrent laryngeal nerve and its aberrations as well as the external branch of the superior laryngeal nerve during thyroid surgery.

Conclusion: The findings from this case suggest that an extralaryngeal bifurcation of the recurrent laryngeal nerve can be identified and safely preserved by intraoperative neuromonitoring.

Staged Thyroidectomy: A Single Institution Perspective

Background

The increasing use of intraoperative neuromonitoring (IONM) in thyroid surgery has revealed the need to develop new strategies for cases in which a loss of signal (LOS) occurs on the first side of a planned total thyroidectomy.

Objectives

This study reviews the experience of the authors in using IONM for planned total thyroidectomy after LOS on the first thyroid lobe. The aims were to estimate the incidence of LOS on the first side of resection and to compare intraoperative strategies applied after this event.

Materials and Methods

Intermittent IONM was performed with stimulation of both the vagal nerve and the recurrent laryngeal nerve (RLN) (V1, R1, R2, V2). Patients underwent pre- and postoperative laryngoscopy. Before surgery, patients were informed that staged thyroidectomy might be required.

Results

This study analyzed 803 consecutive thyroid procedures. Of these, V2 LOS (<100 mcV) occurred after first lobe exeresis in 23 (2.8%) procedures. The surgical procedure was stopped in 20 cases (ie, staged thyroidectomy was performed). In three cases with malignancy and severe comorbidity (ASA score 3-4), total bilateral thyroidectomy was performed as planned. No cases of bilateral RLN palsy occurred. Postoperative laryngoscopy confirmed RLN palsy in 21 of the 23 cases. All true positive patients received speech therapy. Patients who had false positive LOS (n = 2) or malignancy (n = 8) and patients who were symptomatic (n = 7) received completion thyroidectomy within 6 months. One patient received radioactive iodine therapy for hyperthyroidism. Two patients received follow up.

Conclusions

Neuromonitoring changes the surgical decision-making process in a multidisciplinary manner. A shared decision-making process involving the patient, anesthesiologist, and endocrinologist is suggested. In the case of intraoperative LOS on the first-operated side in a planned total thyroidectomy, the thyroid surgeon essentially has three options for surgery on the contralateral side: 1) Perform staged thyroidectomy. This option is recommended in bilateral goiter, Graves' disease, or low-risk thyroid carcinoma (differentiated or medullary thyroid carcinoma). The aim is to avoid bilateral vocal cord palsy. Two-stage completion surgery is delayed until recovery of ipsilateral nerve function. 2) Perform subtotal resection on the contralateral side ventrally to the RLN plane at a safe distance from the nerve. The aim is to avoid further disease recurrence and revision surgery. 3) Perform total thyroidectomy as planned for advanced thyroid carcinoma (including undifferentiated thyroid carcinoma). The aim is to improve disease control through radioactive iodine therapy, radiation therapy, or target therapy immediately after surgery.

Level of Evidence

4.

A Review of Methods for the Preservation of Laryngeal Nerves During Thyroidectomy

The recurrent laryngeal nerve (RLN) provides motor innervation to the abductor and adductor muscles of the vocal cord, whereas the external branch of the superior laryngeal nerve (EBSLN) provides motor innervation to the cricothyroid muscle, which is the tensor muscle of the vocal cord. Both the RLN and the EBSLN are anatomically close to the thyroid and are therefore at risk of injury during thyroidectomy. These 2 laryngeal nerves must be carefully preserved during surgery to ensure that the function of the vocal cord is not impaired. Currently, complete exposure of the RLN during thyroidectomy is accepted as the gold standard method for the preservation of RLN. Sufficient knowledge of surgical anatomy, clinical experience, and meticulous surgical techniques are key factors in the identification and safe dissection of the RLN. During a thyroidectomy, the RLN can be identified using four different approaches, depending on the type of thyroid growth and choice of the surgeon: There are lateral, inferior, superior, and medial approaches.

The lateral approach is the most commonly used technique in primary thyroid surgery. The RLN is usually found by dissection around the inferior thyroid artery at the level of the middle lobe of the thyroid. RLN is generally found at the site of its entry into the neck region devoid of scar formation when the inferior approach is used especially in cases with secondary surgery. The superior approach is recommended for patients with an huge goiter or large substernal goiter. In this approach, the upper pole of the thyroid is first released and then pulled forward and laterally, and the RLN is exposed on the nerve’s entry point (NEP), into the larynx, under the cricopharyngeus muscle. The medial approach is preferred for patients with substernally or retropharyngeally enlarged goiters. In this approach, the isthmus is first dissected and divided, and then the isthmus and the medial part of the lobe are dissected away from the trachea to reveal the anterolateral part of the trachea. The fibers between the lateral aspect of the second or third tracheal rings and the thyroid, and the fibers of the Berry ligament are gradually dissected cranially, to allow RLN to enter into the field of view lateral to the trachea. The preservation of the anatomical integrity of the RLN does not indicate that its functional integrity is also preserved. IONM is a tool for the functional assessment of RLN, and so this method is an addition to visually identifying RLN, which is the gold standard. IONM significantly contributes to visual identification of the RLN, determination of its anatomical variations, intraoperative recognition of RLN injury, prevention of bilateral vocal cord paralysis, and detection and preservation of electrical activity in the nerve in patients with preoperative vocal cord paralysis.

Although there is no standardized method for the preservation of the EBSLN, 3 methods have been defined during the release of the upper pole of the thyroid. These methods involve dividing the branches of the superior thyroidal artery one by one on the capsule without visually identifying the EBSLN, searching and visually identifying the EBSLN before the dissection of the upper pole vessels, or detecting the EBSLN and dissecting the upper pole under the guidance of IONM. IONM also significantly contributes to the detection and confirmation of the EBSLN and dissection and preservation of the upper pole of the thyroid gland.

Protective Effects of Intraoperative Nerve Monitoring (IONM) for Recurrent Laryngeal Nerve Injury in Thyroidectomy: Meta-analysis

Recurrent laryngeal nerve (RLN) injury is an intractable complication of thyroidectomy. Intraoperative nerve monitoring (IONM) was designed to prevent RLN injury. However, the results concerning the protective effect of IONM on RLN injury are still controversial. We searched all eligible databases from 1980 to 2017. Meta-analysis was performed to evaluate the effect of IONM on RLN injury. Sensitivity analysis was also conducted to check the stability of our results. There were 34 studies included in the analysis. Overall analysis found a significant decrease in total injury (RR = 0.68, 95%CI: 0.55 to 0.83), transient injury (RR = 0.71, 95%CI: 0.57 to 0.88), and permanent injury (RD = −0.0026, 95%CI: −0.0039 to −0.0012) with IONM. Subgroup analysis found IONM played a preventive role of total, transient and permanent injury in patients undergoing bilateral thyroidectomy. IONM also reduced the incidence of total and transient injury for malignancy cases. Operations with IONM were associated with fewer total and transient RLN injuries in operation volume < 300 NARs per year and fewer total and permanent RLN injuries in operation volume ≥ 300 NARs per year. The application of IONM could reduce the RLN injury of thyroidectomy. Particularly, we recommend routine IONM for use in bilateral operations and malignancy operations.

Intraoperative neuromonitoring in thyroid surgery: Is the two-staged thyroidectomy justified?

BACKGROUND

The aim of this study was to evaluate the diagnostic accuracy of intraoperative neuromonitoring (IONM) in predicting postoperative nerve function during thyroid surgery and its consequent ability to assist the surgeon in intraoperative decision making.

MATERIALS AND METHODS

A total of 2365 consecutive patients were submitted to thyroidectomy by the same surgical team. Group A included 1356 patients (2712 nerves at risk) in whom IONM was utilized, and Group B included 1009 patients (2018 nerves at risk) in whom IONM was not utilized.

RESULTS

In Group A, loss of signal (LOS) was observed in 37 patients; there were 29 true positive, 1317 true negative, 8 false positive, and 2 false negative cases. Accuracy was 99.3%, positive predictive value was 78.4%, negative predictive value was 99.8%, sensitivity was 93.6%, and specificity was 99.4%. A total of 29 (2.1%) cases of unilateral paralysis were observed, 23 (1.7%) of which were transient and 6 (0.4%) of which were permanent. Bilateral palsy was observed in two (0.1%) cases requiring a tracheostomy. In Group A, 31 (2.3%) injuries were observed, 25 (1.8%) of which were transient and 6 (0.4%) of which were permanent. In Group B, 26 (2.6%) unilateral paralysis cases were observed, 20 (2%) of which were transient and 6 (0.6%) of which were permanent; bilateral palsy was observed in 2 (0.2%) cases. In Group B, 28 (2.8%) injuries were observed, 21 (2.1%) of which were transient and 7 (0.7%) of which were permanent. Differences between the two groups were not statistically significant.

CONCLUSIONS

Our results show that IONM has a very high sensitivity and negative predictive value, but also good specificity and positive predictive value. For these reasons, in selected patients with LOS, the surgical strategy should be reconsidered. However, patients need to be informed preoperatively about potential strategy changes during the planned bilateral surgery. Future larger and multicenter studies are needed to confirm the benefits of this therapeutic strategy.

Does intraoperative neuromonitoring of recurrent nerves have an impact on the postoperative palsy rate? Results of a prospective multicenter study

BACKGROUND

The impact of intraoperative neuromonitoring on recurrent laryngeal nerve palsy remains debated. Our aim was to evaluate the potential protective effect of intraoperative neuromonitoring on recurrent laryngeal nerve during total thyroidectomy.

METHODS

This was a prospective, multicenter French national study. The use of intraoperative neuromonitoring was left at the surgeons' choice. Postoperative laryngoscopy was performed systematically at day 1 to 2 after operation and at 6 months in case of postoperative recurrent laryngeal nerve palsy. Univariate and multivariate analyses and propensity score (sensitivity analysis) were performed to compare recurrent laryngeal nerve palsy rates between patients operated with or without intraoperative neuromonitoring.

RESULTS

Among 1,328 patients included (females 79.9%, median age 51.2 years, median body mass index 25.6 kg/m²), 807 (60.8%) underwent intraoperative neuromonitoring. Postoperative abnormal vocal cord mobility was diagnosed in 131 patients (9.92%), including 69 (8.6%) and 62 (12.1%) in the intraoperative neuromonitoring and nonintraoperative neuromonitoring groups, respectively. Intraoperative neuromonitoring was associated with a lesser rate of recurrent laryngeal nerve palsy in univariate analysis (odds ratio = 0.68, 95% confidence interval, 0.47; 0.98, P = .04) but not in multivariate analysis (oddsratio = 0.74, 95% confidence interval, 0.47; 1.17, P = .19), or when using a propensity score (odds ratio = 0.76, 95% confidence interval, 0.53; 1.07, P = .11). There was no difference in the rates of definitive recurrent laryngeal nerve palsy (0.8% and 1.3% in intraoperative neuromonitoring and non-intraoperative neuromonitoring groups respectively, P = .39). The sensitivity, specificity, and positive and negative predictive values of intraoperative neuromonitoring for detecting abnormal postoperative vocal cord mobility were 29%, 98%, 61%, and 94%, respectively.

CONCLUSION

The use of intraoperative neuromonitoring does not decrease postoperative recurrent laryngeal nerve palsy rate. Due to its high specificity, however, intraoperative neuromonitoring is useful to predict normal vocal cord mobility. From the CHU de Nantes,^a Clinique de Chirurgie Digestive et Endocrinienne, Nantes, France; CHU Lille, Université de Lille,^b Chirurgie Générale et Endocrinienne, Lille, France; CHU Nancy-Hôpital de Brabois,^c Service de Chirurgie Digestive, Hépato-Biliaire, et Endocrinienne, Nancy, France; CHU Angers,^d Chirurgie Digestive et Endocrinienne, Angers, France; CHU de Toulouse-Hôpital Larrey,^e Chirurgie Thoracique, Pôle Voies Respiratoires, Toulouse; CHU Saint-Etienne-Hôpital Nord,^f ORL et Chirurgie Cervico-Faciale et Plastique, Saint-Etienne, France; CHU de Limoges-Hôpital Dupuytren,^g Chirurgie Digestive, Générale et Endocrinienne, Limoges, France; CHU de Besançon-Hôpital Jean Minjoz,^h Chirurgie Digestive, Besançon, France; Centre Hospitalier du Mans,ⁱ Service ORL et Chirurgie Cervico-Faciale, Le Mans, France; Centre Hospitalier Lyon-Sud,^j Chirurgie Générale, Endocrinienne, Digestive et Thoracique, Pierre Bénite, France; AP-HM-Hôpital de La Conception,^k Chirurgie Générale, Marseille, France; CHU de Rennes-Hôpital Pontchaillou,^l Service ORL et Chirurgie Maxillo-Faciale, Rennes, France; CHU de Caen,^m ORL et Chirurgie Cervico-Faciale, Caen, France; CHU d'Angers,ⁿ ORL et Chirurgie Cervico-Faciale, Angers, France; CHU de Nantes,^o Service ORL, Nantes, France; AP HP URCEco île-de-France,^p hôpital de l'Hôtel-Dieu, Paris, France; DRCI, département Promotion,^q Nantes, France.

Two-stage thyroidectomy in the era of intraoperative neuromonitoring

Background

The use of intraoperative neuromonitoring (IONM) provides surgeons with real time information about recurrent laryngeal nerves (RLN) functional integrity. Hence, allowing them to modify the initially scheduled bilateral procedure, to a two-stage thyroidectomy in cases of loss of signal (LOS) on the first side of resection resulting in minimization of bilateral RLN injury. The purpose of our study was to present our results since the implementation of the above mentioned process in both malignant and benign thyroid disease.

Methods

We conducted a retrospective, observational cohort study of prospectively collected data from all patients who underwent a scheduled total thyroidectomy with or without neck dissection in our Department over the last 4 years [2013-2016]. From the 1,138 patients who received surgical treatment during that period, 284 were excluded since they did not meet the criteria. Exclusion criteria involved previous neck operation, parathyroid surgery, pre-existing vocal cord palsy (VCP) and unilateral surgery. A total of 854 patients were eligible for our study. All patients were subjected to pre- and postoperative indirect laryngoscopy by the same experienced ENT specialist team and all the surgeries were performed by the same experienced team. The whole procedure followed the International Neural Monitoring Study Group's (INMSG) Guideline Statement.

Results

We experienced 70 cases (70/854, 8.2%) with postoperative VCP. Two of them (0.23%) had permanent VCP and the rest of those patients (7.97%) experienced transient VCP. Twenty-three (2.7%) patients were candidates for staged thyroidectomy after LOS on the first side of resection, including ten patients with papillary or medullary thyroid carcinoma and one with toxic multinodular goiter (MNG). Of those patients, 22 incidents of VCP (95.7%) have recovered within two months and one of them persisted for more than six months (permanent VCP). We did not experience any permanent bilateral RLN palsy after the implementation of the staged procedure.

Conclusions

Staged thyroidectomy seems a very attractive and promising procedure for both patient and surgeon, since it nearly eliminates one of the most fearful complications in thyroid surgery. We suggest staged thyroidectomy in all cases with first side of resection signal loss, even in malignancies, since the benefits are much more than the disabilities in a patient's morbidity and quality of life.

Utility of intraoperative nerve monitoring in thyroid surgery: 20-year experience with 1418 cases

PURPOSE

The efficacy of intraoperative nerve monitoring is controversial in the literature. This study of a single surgeon's experience seeks to determine if the use of intraoperative nerve monitoring influences recurrent laryngeal nerve injury during thyroid surgery.

METHODS

Six hundred fifty-seven patients with normal pre-operative vocal fold function underwent thyroid surgery without the use of intraoperative nerve monitoring from September 1997 to January 2007, while 761 patients underwent thyroid surgery from February 2007 to February 2016 with routine use of nerve monitoring. Patients were followed for a minimum of 6 months after surgery, and postoperative nerve function was determined by fiberoptic laryngoscopy. A Fisher test was used to determine if nerve injury was statistically different between both groups.

RESULTS

In patients operated on without nerve monitoring, 21 patients were found to have postoperative vocal fold paralysis with nine regaining functioning. In patients operated on with nerve monitoring, 27 were found to have vocal fold dysfunction with 17 regaining function. Fisher test analysis, both with and without patients regaining function, showed no difference in nerve injury between groups (p > 0.05, p > 0.05).

CONCLUSION

Intraoperative monitoring during thyroidectomy may not prevent injury to the recurrent laryngeal nerve.

Cost-effectiveness of intraoperative nerve monitoring in avoidance of bilateral recurrent laryngeal nerve injury in patients undergoing total thyroidectomy

Background

Intraoperative nerve monitoring (IONM) provides dynamic neural information and is recommended for high-risk thyroid surgery. In this analysis, the cost-effectiveness of IONM in preventing bilateral recurrent laryngeal nerve (RLN) injury was investigated.

Methods

A Markov chain model was constructed based on IONM use. The base-case patient was defined as a 40-year-old woman presenting with a 4·1-cm left-sided papillary thyroid cancer who developed RLN injury with loss of monitoring signal during planned bilateral thyroidectomy. It was hypothesized that, if the surgeon had used IONM, the RLN injury would have been detected and the operation would have been concluded as a thyroid lobectomy to avoid the risk of contralateral RLN injury. Cost in US dollars was converted to euros; probabilities and utility scores were identified from the literature and government resources. Length of follow-up was set as 20 years, and willingness-to-pay (WTP) as €38 000 (US $50 000) per quality-adjusted life-year (QALY).

Results

At the end of year 20, the not using IONM strategy accrued €163 995·40 (US $215 783·43) and an effectiveness of 14·15 QALYs, whereas use of the IONM strategy accrued €170 283·68 (US $224 057·48) and an effectiveness of 14·33 QALYs. The incremental cost–effectiveness ratio, comparing use versus no use of IONM, was €35 285·26 (US $46 427·97) per QALY, which is below the proposed WTP, indicating that IONM is the preferred and cost-effective management plan. A Monte Carlo simulation test that considered variability of the main study factors in a hypothetical sample of 10 000 patients showed IONM to be the preferred strategy in 85·8 per cent of the population.

Conclusion

Use of IONM is cost-effective in patients undergoing bilateral thyroid surgery.

Indications and extent of central neck dissection for papillary thyroid cancer: An American Head and Neck Society Consensus Statement

BACKGROUND

The primary purposes of this interdisciplinary consensus statement were to review the relevant indications for central neck dissection (CND) in patients with papillary thyroid cancer (PTC) and to outline the appropriate extent and relevant techniques required to accomplish a safe and effective CND.

METHODS

A writing group convened by the American Head and Neck Society (AHNS) Endocrine Committee was tasked with identifying the important clinical elements to consider when managing the central neck compartment in patients with PTC based on available evidence in the literature, and the group's collective experience. The position statement paper was then submitted to the full Endocrine Committee, Education Committee, and AHNS Council.

RESULTS

This consensus statement was developed to inform the clinical decision-making process when managing the central neck compartment in patients with PTC from the AHNS. This document is intended to provide clarity through definitions as well as a basic guideline from which to manage the central neck. It is our hope that this improves the quality and reduces variation in management of the central neck, facilitates communication, and furthers research for patients with thyroid cancer.

CONCLUSION

This represents, in our opinion, contemporary optimal surgical care for this patient population and is endorsed by the American Head and Neck Society. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1269-1279, 2017.

Staged Surgery for Advanced Thyroid Cancers: Safety and Oncologic Outcomes of Neural Monitored Surgery

Objective

Thyroidectomy with extensive multicompartment bilateral neck dissections for advanced-stage thyroid cancer may lead to increased risk of complications, including bilateral recurrent laryngeal nerve (RLN) paralysis and hypoparathyroidism. A planned staged approach derived from a detailed preoperative radiographic map is associated with a low complication profile. This study evaluates oncologic results and safety of neural monitored, staged thyroid cancer surgery for management of advanced thyroid cancer.

Study Design

Case series with chart review.

Setting

Tertiary care center.

Subjects and Methods

With institutional review board approval, 35 consecutive patients with advanced thyroid malignancy and extensive nodal disease managed with staged surgery between January 2004 and May 2013 by the senior author (G.W.R.) were identified, and the oncologic and surgical outcomes were reviewed.

Results

In total, 37.2% of patients had stage III or IV disease, with extrathyroidal extension in 71.4%, vascular invasion in 51.4%, and RLN invasion in 17% of patients. A total of 34% patients had positive lymph nodes in more than 5 nodal compartments; the average positive lymph node yield was 17, and extranodal extension was present in 51%. Three patients had RLN sacrifice, and there were no other cases of temporary or permanent RLN paralysis; permanent hypoparathyroidism and chyle leak occurred in one patient each. Locoregional recurrence occurred in 5.7% of patients after a 147-week mean follow-up. In patients with papillary thyroid carcinoma, median postoperative nonstimulated and stimulated thyroglobulin levels were 0.2 and 0.75 ng/mL, respectively.

Conclusion

A neural monitored, staged surgical approach was conducted without significant adverse events in this small sample and represents and effective alternative strategy option to simultaneous bilateral surgery in the management of thyroid cancer with extensive neck metastases.

Risk of recurrent laryngeal nerve palsy in patients undergoing thyroidectomy with and without intraoperative nerve monitoring

BACKGROUND

Vocal cord palsy occurs in 3-5 per cent of patients after thyroidectomy. To reduce this complication, intraoperative nerve monitoring (IONM) has been introduced, although its use remains controversial. This study investigated the risk of postoperative vocal cord palsy with and without the use of intermittent IONM.

METHODS

Patients registered in the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery, 2009-2013, were included. Early palsy of the recurrent laryngeal nerve was diagnosed within 6 weeks after surgery. Permanent palsy was defined as that persisting after 6 months. Univariable and multivariable logistic regression analyses were used to examine risk factors for vocal cord palsy.

RESULTS

The cohort consisted of 5252 patients undergoing thyroidectomy. IONM was used in 3277 operations (62·4 per cent); postoperative laryngoscopy was performed in 1757 patients (33·5 per cent). Early vocal cord palsy occurred in 217 patients (4·1 per cent), of which three were bilateral, all in the group without IONM. Permanent vocal cord palsy occurred in 62 patients (1·2 per cent). In the multivariable analysis of 1757 patients who had postoperative laryngoscopy, the use of IONM was not associated with a decreased risk of early vocal cord palsy (odds ratio (OR) 0·67, 95 per cent c.i. 0·44 to 1·01), but decreased the risk of permanent vocal cord palsy (OR 0·43, 0·19 to 0·93). [Correction added on 11 November 2016 after first publication: the word 'routine' has been removed from this section.] CONCLUSION: IONM reduced the risk of permanent vocal cord palsy. No bilateral recurrent laryngeal nerve injury occurred following IONM.

Intraoperative electrophysiologic monitoring of the recurrent laryngeal nerve during thyroid and parathyroid surgery: Experience with 1,381 nerves at risk

OBJECTIVES

The electrophysiologic responses of 1,381 recurrent laryngeal nerves (RLN) during monitored neck surgery were recorded and reviewed.

STUDY DESIGN

Retrospective case series.

METHODS

With institutional review board approval, we reviewed thyroid and other neck surgeries performed with intraoperative nerve monitoring (IONM) between the years 1995 and 2006. This list yielded consecutively monitored 1,381 RLNs, with over 3,000 hours of monitoring experience. All patients underwent preoperative and postoperative laryngoscopy. In an initial subset of patients, both hook-wire and endotracheal tube (ETT) surface electrodes were utilized. Normative stimulation parameters; postoperative vocal cord function prognostication using monitoring data; and false-positive, false-negative, and passive electrophysiologic responses were evaluated RESULTS: Hook-wire electrodes and ETT surface electrodes were found to have good correlation in terms of amplitude (correlation coefficient, R = 0.89). Nerve stimulation of 1 to 2 mA resulted in an ipsilateral biphasic response, with 3.3 ms mean latency and 900 μV mean amplitude. Permanent and temporary RLN paralysis rates were 0% and 0.7%, respectively. Specificity of electromyography (EMG) loss of signal (LOS) postoperative vocal cord paralysis (VCP) detection was 99.9%, and sensitivity was 33%. Negative predictive value of EMG LOS at the end of surgery in the prediction of postoperative VCP was 99.6%, whereas its positive predictive value for VCP was 75%.

CONCLUSION

Intraoperative nerve monitoring of the RLN during thyroid and other neck surgeries can aid in the nerve mapping, nerve identification, and prognostication of postoperative vocal cord function, which in turn can influence the surgeon's decision to proceed to bilateral surgery.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:280-286, 2017.

Recurrent laryngeal nerve injury in thyroid surgery: Clinical pathways and resources consumption

BACKGROUND

The impact of recurrent laryngeal nerve (RLN) injury management in thyroid surgery seems to be relevant to patients, National Healthcare System (NHS), and society.

METHODS

We studied resource consumption in the management of patients with RLN injury versus noninjured patients investigating 3 perspectives (patients, NHS, and society) in 5 clinical pathways.

RESULTS

Direct medical costs supported by the NHS range from a minimum of euro (€) 79.46 to a maximum of € 3261.95. From the patient's perspective, the direct medical costs supported by the patient increased from a minimum of € 3.60 to a maximum of € 499.45. Productivity losses were accounted in € 156 per day per patient. From the NHS perspective, the percentage increase ranged from 43.25% to 98.14%. From the patient's perspective, it ranged from 51.52% to 80.60%.

CONCLUSION

The analysis shows a significant economic impact of RLN injury management, which varies depending on the damage, duration, and severity. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.

Prognostic value of intraoperative neural monitoring of the recurrent laryngeal nerve in thyroid surgery

Purpose

The diagnostic accuracy of intraoperative recurrent laryngeal nerve (RLN) monitoring (IONM) remains controversial. The aim of this study was to evaluate IONM diagnostic accuracy in prognostication of postoperative nerve function in thyroid surgery.

Methods

This prospective study was conducted in 2011–2013. Five hundred consenting patients qualified for total thyroidectomy with IONM (1000 nerves at risk) using NIM 3.0 Response equipment were included. Laryngoscopy was used to evaluate and follow up RLN injury. The primary outcome was diagnostic accuracy of IONM. The receiver operating characteristics (ROC) were used for evaluation of IONM diagnostic accuracy.

Results

Loss of signal (LOS) occurred in 31 cases, including 25 patients with LOS and corresponding vocal fold paresis found in postoperative laryngoscopy (2.5 %), including 20 (2.0 %) temporary and 5 (0.5 %) permanent nerve lesions. The following diagnostic accuracy values were calculated for the criterion recommended by INMSG (V2 amplitude ≤ 100 μV): sensitivity 92.0 %, specificity 99.3 %, positive predictive value (PPV) 76.7 %, and negative predictive value (NPV) 99.8 %. The ROC curve analysis allowed for calculation of the most optimal criterion in prognostication of postoperative vocal fold paresis, namely, V2 amplitude ≤ 189 μV. For this criterion, PPV was 77.4 %, while NPV was 99.9 %.

Conclusions

Adherence to the standardized protocol recommended by the International Neural Monitoring Study Group allows for optimizing predictive values of IONM in prognostication of postoperative RLN function. Any changes in the cutoff values for the definition of LOS only marginally improve PPV and NPV of IONM and need to be carefully assessed in multicenter studies.

Successful intraoperative electrophysiologic monitoring of the recurrent laryngeal nerve, a multidisciplinary approach: The Massachusetts Eye and Ear Infirmary monitoring collaborative protocol with experience in over 3000 cases

BACKGROUND

Although intraoperative nerve monitoring (IONM) is utilized increasingly, the information on the related anesthesia technique is limited. This study presents an up-to-date clinical algorithm, including setup and troubleshooting of an IONM system, endotracheal tube placement, and anesthetic parameters. To our knowledge, this is the first interdisciplinary collaborative protocol for monitored neck surgery based on the published evidence and clinical experience.

METHODS

The Departments of Otolaryngology Head and Neck Surgery, Anesthesiology, and Audiology collaboratively developed a protocol for IONM of the recurrent laryngeal nerve (RLN) based on published evidence and our experience with 3000 patients over a 16-year period.

RESULTS

No complications related to monitoring or endotracheal tube placement were noted when the IONM protocol was implemented at Massachusetts Eye and Ear Infirmary (MEEI). The IONM protocol has proven to be vital in standardizing care and in avoiding intraoperative errors.

CONCLUSION

An IONM system entails an anesthesiologist who understands the challenges posed by this technique; muscle relaxation must be minimized/eliminated to optimize IONM. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-1494, 2016.