A meta-analysis of intraoperative neuromonitoring of recurrent laryngeal nerve palsy during thyroid reoperations

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

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

Does the Use of Intraoperative Neuromonitoring during Thyroid and Parathyroid Surgery Reduce the Incidence of Recurrent Laryngeal Nerve Injuries? A Systematic Review and Meta-Analysis

Injury to the recurrent laryngeal nerve (RLN) can be a devastating complication of thyroid and parathyroid surgery. Intraoperative neuromonitoring (IONM) has been proposed as a method to reduce the number of RLN injuries but the data are inconsistent. We performed a meta-analysis to critically assess the data. After applying inclusion and exclusion criteria, 60 studies, including five randomized trials and eight non-randomized prospective trials, were included. A meta-analysis of all studies demonstrated an odds ratio (OR) of 0.66 (95% CI [0.56, 0.79], p < 0.00001) favoring IONM compared to the visual identification of the RLN in limiting permanent RLN injuries. A meta-analysis of studies employing contemporaneous controls and routine postoperative laryngoscopy to diagnose RLN injuries (considered to be the most reliable design) demonstrated an OR of 0.69 (95% CI [0.56, 0.84], p = 0.0003), favoring IONM. Strong consideration should be given to employing IONM when performing thyroid and parathyroid surgery.

Ultrasound-Guided Radiofrequency Ablation versus Thyroidectomy for the Treatment of Benign Thyroid Nodules in Elderly Patients: A Propensity-Matched Cohort Study

BACKGROUND AND PURPOSE

Ultrasound-guided radiofrequency ablation has been recommended as an alternative to surgery for benign thyroid nodules. However, little is known about the benefit from the application of radiofrequency ablation for benign thyroid nodules in elderly patients. The purpose of this study was to compare the clinical outcomes of radiofrequency ablation versus thyroidectomy for elderly patients with benign thyroid nodules.

MATERIALS AND METHODS

This retrospective study evaluated 230 elderly patients (60 years of age or older) with benign thyroid nodules treated with radiofrequency ablation (R group, n = 49) or thyroidectomy (T group, n = 181). Complications, thyroid function, and treatment variables, including procedural time, estimated blood loss, hospitalization, and cost, were compared after propensity score matching. The volume, volume reduction rate, symptoms, and cosmetic score were also evaluated in the R group.

RESULTS

After 1:1 matching, each group had 49 elderly patients. The rate of overall complications and hypothyroidism was 26.5% and 20.4% in the T group, respectively, but these complications were totally absent from the R group (P < .001, P = .001). Patients in the R group had a significantly shorter procedural time (median, 4.8 versus 95.0 minutes, P < .001) and lower cost (US $1979.02 versus US $2208.80, P = .013) than those treated by thyroidectomy. After radiofrequency ablation, the volume reduction rate was 94.1%, and 12.2% of nodules had completely disappeared. The symptom and cosmetic scores were both significantly reduced at the last follow-up.

CONCLUSIONS

Radiofrequency ablation could be considered as a first-line treatment for elderly patients with benign thyroid nodules.

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.

Advancements in Thyroidectomy: A Mini Review

Demand for minimally invasive surgery has driven the development of new gadgets and surgical techniques. Yet, questions about safety and skeptical views on new technology have prevented proliferation of new modes of surgery. This skepticism is perhaps due to unfamiliarity of new fields. Likewise, there are currently various remote-access techniques available for thyroid surgeons that only few regions in the world have adapted. This review will explore the history of minimally invasive techniques in thyroid surgery and introduce new technology to be implemented.

SFE-AFCE-SFMN 2022 consensus on the management of thyroid nodules: Surgical treatment

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French-speaking Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the surgical management of thyroid nodules.

The learning curve and safety of continuous intraoperative vagus nerve monitoring in thyroid surgery

INTRODUCTION

Continuous intraoperative nerve monitoring allows for continuous feedback on the integrity of the recurrent laryngeal nerve (RLN) and the quality of its induced myogenic potential. The aims of this study were to assess the time requirements and risks associated with vagus nerve electrode placement when learning the technique.

METHODS

This is a prospective observational study carried out in a single otolaryngology department at the start of a trainee's placement. A total of 40 vagus nerve dissections in 31 consecutive operations (22 hemithyroidectomies, 9 total thyroidectomies) using automatic periodic stimulation (APS, Medtronic) are included. Of the electrode placements, 10 were performed by the trainer and 30 by the trainee. The time required for each surgical step and complications relating to vagus nerve dissection were recorded.

RESULTS

The average (median+IQR) total additional time attributable to vagus nerve dissection, electrode placement and baseline electromyogenic assessment was 3.1mins (2.5-3.3) for the trainer and 4.8mins (4.1-5.3) for the trainee (p<0.0001). There was a downward trend in time requirement for the trainee (not statistically significant, p=0.080). Total operative time was 38min (35-45) for hemithyroidectomy and 56min (53-62) for total thyroidectomy. There was a mix of benign (74%) and malignant (26%) histology, no intraoperative complications relating to autonomic dysfunction and one (2.5%) transient nerve palsy.

CONCLUSIONS

Operative time attributable to vagus nerve electrode placement is short and the procedure is easy to learn. Appropriate surgical technique and careful anaesthetic considerations allow monitoring to be performed safely, and may reduce the rate of RLN palsy.

Intraoperative neuromonitoring of the recurrent laryngeal nerve is indispensable during complete endoscopic radical resection of thyroid cancer: A retrospective study

Objective

Complete endoscopic radical resection of thyroid cancer, especially through the areolar approach, can achieve curative and acceptable cosmetic effects in patients with differentiated thyroid carcinoma. However, some inherent characteristics of endoscopic procedures hamper functional protection of the recurrent laryngeal nerve (RLN). Intraoperative neuromonitoring (IONM) is considered the most important accessory to protect the nerves during conventional radical thyroidectomy. This study aimed to evaluate the feasibility and necessity of IONM during complete endoscopic radical resection of thyroid cancer.

Methods

A total of 106 patients with differentiated thyroid carcinoma were enrolled in the study between February 2013 and April 2018. Based on the use of the IONM technique, all patients were divided into the IONM (n = 54) and non-IONM groups (n = 52). Overall, 66 RLNs were involved in the IONM group, and 61 RLNs were involved in the non-IONM group. The time and ratio of RLN identification and the number of transient and permanent RLN injuries between both groups were compared.

Results

Compared to the non-IONM group, the IONM group required less time for RLN identification (3.05 ± 1.58 vs. 9.36 ± 4.82 min, p < .01). The ratio of RLN identification in the IONM group was much higher than that in the non-IONM group (100.00% vs. 88.52%, p = .01). A significant difference was observed in RLN transient injury between the two groups (one case accounting for 1.51% in the IONM group vs. eight cases accounting for 13.11% in the non-IONM group; p = .03).

Conclusion

IONM significantly improved RLN identification and reduced transient RLN injuries during complete endoscopic radical resection.

Level of Evidence

3b.

Effect of Intraoperative Neuromonitoring on the Risks of Recurrent Laryngeal Nerve Injury During Thyroidectomy: A Doubly Robust Approach

OBJECTIVE

To evaluate the relationship between the use intraoperative neuromonitoring (IONM) during thyroidectomy and the risk of recurrent laryngeal nerve (RLN)injury.

BACKGROUND

The role of IONM in reducing RLN injury during thyroidectomy remains controversial. Several studies on this topic apply conventional multivariable regression to adjust for confounding. However, estimates from this method may be biased due to model misspecification, especially with a rare outcome such as RLN injury.

METHODS

We used a pooled dataset created by linking the 2016 - 2019 NSQIP General Participant User File with the corresponding Targeted-Thyroidectomy file. The primary outcome was RLN injury rates, and the secondary outcomes were operating time and postoperative length of stay. A doubly robust (DR) estimator, in the form of an inverse-probability-weighted regression adjustment model, was used to estimate the effect of the use of IONM on the risk of RLN injury. Sensitivity analyses was performed.

RESULTS

Twenty-four thousand three hundred seventy patients were evaluated, out of which 15,836 (70%) patients had IONM during thyroidectomy, and RLN injury occurred in 1,498 (6.2%) cases. Rates of RLN injury increase with increasing age and BMI and are higher in patients with a cancer diagnosis, previous neck operation, total thyroidectomy, and node dissection. DR model suggests that the use of IONM was associated with a significant reduction in overall rate of RLN injury (RR 0.77(CI, 0.68 to 0.87),P<0.001], and postoperative length of stay [-2.5 h(CI, -4.18 to - 0.81 h)P=0.004)]. However, IONM use was associated with an increase in operating time [15.41mins(CI, 13.29-14.54 mins, P<0.0001)]. Sensitivity analyses revealed that our estimates are largely robust to confounding.

CONCLUSION

In a balanced cohort of patients undergoing thyroidectomy from multiple sites and surgeons participating in NSQIP, the use of IONM during thyroidectomy was associated with reduction in RLN injury.

Utility of the continuous intraoperative neuromonitoring in the prevention of the recurrent laryngeal nerve paralysis during thyroid surgery. A prospective observational study

BACKGROUND

The continuous intraoperative neuromonitoring (C-IONM) of the recurrent laryngeal nerve (RLN) could help reducing the incidence of nerve paralysis after thyroid surgery, in comparison with the mere anatomical visualization of the RLN. The objective is to assess the efficacy and utility of C-IONM as a predictive test for recurrent laryngeal nerve paralysis after thyroidectomy.

METHODS

A prospective observational study was performed in 248 patients who underwent thyroid surgery where C-IONM was applied, between September 2018 and December 2019, in a high-volume center. A previous and later laryngoscopy was performed, which allowed to evaluate the reliability of the C-IONM as a predictive test for recurrent paralysis. Sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) were studied.

RESULTS

A total number of 171 thyroidectomies, 62 hemithyroidectomies, 15 totalization thyroidectomies and 27 thyroidectomy with cervical dissections were performed. Postoperative laryngoscopy was altered in 40 patients (16.12%). The SE, SP, PPV and NPV values ​​were 65%, 94.7%, 70.2% and 93.4% respectively.

CONCLUSIONS

C-IONM is a safe technique that provides real-time information about anatomical and functional integrity of the RLN and can improve the results of thyroid surgery.

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.

Intraoperative Neuromonitoring: Evaluating the Role of Continuous IONM and IONM Techniques for Emerging Surgical and Percutaneous Procedures

Intraoperative nerve monitoring (IONM) is a tool used during thyroid surgery to assist in the identification of the recurrent laryngeal nerve (RLN). Multiple IONM systems that exist for thyroidectomy require intubation with an endotracheal tube. Given that one of the advantages of thermal ablation procedures, such as radiofrequency ablation, is that they can be done safely without the use of general anesthesia, nerve monitoring systems that utilize cutaneous surface electrodes have been developed, though are not widely available in the United States. This article will review the use of IONM for RFA including the cutaneous surface electrode system.

Intraoperative Neuromonitoring: Evaluating the Role of Continuous IONM and IONM Techniques for Emerging Surgical and Percutaneous Procedures

Continuous and intermittent intraoperative nerve monitoring (IONM) has become an important asset for endocrine surgeons over the past few decades. The ability to determine neurophysiologic integrity of the recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN) on top of identification and meticulous dissection of the nerve in the surgical field, has allowed for advances in technology and improved outcomes when it comes to prevention of vocal fold immobility. This article aims to compare in review continuous and intermittent nerve monitoring (CIONM, IIONM), as well as review the current paradigms of their use. This article will also discuss the future of intraoperative nerve monitoring technologies in scarless thyroid surgery and percutaneous approaches to thyroid pathology in form of radiofrequency ablation (RFA).

The Effect of Patient Positioning on Intraoperative Neuromonitoring During Thyroid and Parathyroid Surgery

BACKGROUND

Intraoperative neuromonitoring (IONM) has been accepted as a routine adjunct among surgeons who perform thyroid and parathyroid surgeries. Thyroid and parathyroid surgeries use various patient positioning strategies that have poorly understood effects on IONM. The aim of this study was to compare IONM signals between the transaxillary and transcervical approaches.

METHODS

In this retrospective cohort study, we evaluated 463 adult patients who underwent a total of 502 procedures. The procedures performed included total thyroidectomy, right or left hemithyroidectomy, and parathyroidectomy. Vagus nerve and recurrent laryngeal nerve (RLN) latency and amplitude measurements were analyzed intra-operatively. The distances between the vagus nerve and the trachea were measured via ultrasound during transaxillary procedures.

RESULTS

Compared to the transcervical approach, the right vagus nerve latency was significantly decreased in the transaxillary approach. Transaxillary surgery was not associated with increased latency or decreased amplitude on IONM. The distance between the vagus nerve and trachea was significantly decreased post-positioning during transaxillary approaches.

DISCUSSION

Despite differences in patient positioning, a transaxillary approach was not associated with increased stress on the vagus nerve or RLN, according to IONM data. The decreased right vagus nerve latency associated with a transaxillary approach highlights the importance of considering patient positioning and laterality while interpreting IONM data.

Radiofrequency ablation versus reoperation for benign thyroid nodules that developed after previous thyroid surgery

PURPOSE

To compare the clinical outcomes of radiofrequency ablation (RFA) versus reoperation for benign thyroid nodules that developed after previous thyroid surgery.

METHODS

A total of 53 patients with 53 benign nodules developed after previous thyroid surgery were evaluated in this retrospective study. Eighteen patients were treated by RFA (RFA group) and 35 patients underwent reoperation (reoperation group). The efficacy, safety, thyroid function, blood loss, hospitalization, total treatment time, and cost were compared between the two groups.

RESULTS

In the RFA group, the mean volume decreased significantly from 12.78 ± 17.57 ml to 0.94 ± 1.01 ml (p = 0.043) with a volume reduction rate of 85.27 ± 14.35% and significant improvement in symptom and cosmetic scores (all p = 0.001). Therapeutic efficacy was achieved with a single session in all thyroid nodules. The total treatment time (6.12 ± 3.17 min vs. 110.26 ± 44.41 min, p < 0.001), blood loss (0 ml vs. 82.58 ± 105.55 ml, p < 0.001) and hospitalization(0 days vs. 9.66 ± 4.28 days, p < 0.001) were significantly lower in the RFA group than those in reoperation group, but the costs of treatment were similar(2262.12 ± 221.54 USD vs. 2638.04 ± 1062.90 USD, p = 0.081). The incidence of complications was significantly higher in the reoperation group than in the RFA group(31.43 vs. 0%, p < 0.001). Furthermorre, 65.17% of patients developed hypothyroidism after reoperation, whereas the thyroid function of the patients in the RFA group was unaffected.

CONCLUSION

For patients with benign thyroid nodules developed after previous thyroid surgery, RFA can be considered as a safe and effective alternative to reoperation with advantages of maintenance of intact thyroid function and low incidence of complications.

Care and Management of Voice Change for Thyroid Surgery: Korean Society of Laryngology, Phoniatrics and Logopedics Clinical Practice Guideline

Voice change is a common complaint after thyroid surgery and has significant impacts on quality of life. The Korean Society of Laryngology, Phoniatrics, and Logopedics set up a task force team to establish guideline recommendations on education, care, and management related to thyroid surgery. The guideline recommendations include preoperative voice education, management of anticipated voice change during surgery, and comprehensive voice care after thyroid surgery, including in-depth information and up-to-date knowledge based on validated literature. The committee constructed 14 key questions (KQ) in three categories: preoperative (KQ1-2), intraoperative (KQ 3-8), and postoperative (KQ 9-14) management and developed 18 evidence-based recommendations. The Delphi survey reached an agreement on each recommendation. Detailed evidence profiles are presented for each recommendation. The level of evidence for each recommendation is classified into high, moderate, and low-quality. The recommendation's strengths are adjusted to consider the level of evidence resulting in the recommendation and are divided into strong and weak. The guidelines are primarily targeted toward physicians who treat thyroid surgery patients and speech-language pathologists participating in patient care. These guidelines will also help primary care physicians, nurses, healthcare policymakers, and patients improve their understanding of voice changes and voice care after thyroid surgery.

Informed Consent for Intraoperative Neural Monitoring in Thyroid and Parathyroid Surgery - Consensus Statement of the International Neural Monitoring Study Group

In the past decade, the use of intraoperative neural monitoring (IONM) in thyroid and parathyroid surgery has been widely accepted by surgeons as a useful technology for improving laryngeal nerve identification and voice outcomes, facilitating neurophysiological research, educating and training surgeons, and reducing surgical complications and malpractice litigation. Informing patients about IONM is not only good practice and helpful in promoting the efficient use of IONM resources but is indispensable for effective shared decision making between the patient and surgeon. The International Neural Monitoring Study Group (INMSG) feels complete discussion of IONM in the preoperative planning and patient consent process is important in all patients undergoing thyroid and parathyroid surgery. The purpose of this publication is to evaluate the impact of IONM on the informed consent process before thyroid and parathyroid surgery and to review the current INMSG consensus on evidence-based consent. The objective of this consensus statement, which outlines general and specific considerations as well as recommended criteria for informed consent for the use of IONM, is to assist surgeons and patients in the processes of informed consent and shared decision making before thyroid and parathyroid surgery.

Use of intraoperative neural monitoring for prognostication of recovery of vocal mobility and reduction of permanent vocal paralysis after thyroidectomy

INTRODUCTION

The benefits of intraoperative neural monitoring (IONM) of recurrent laryngeal nerve (RLN) on post-thyroidectomy vocal cord palsy (VCP) rates are contentious. We wished to study impact of IONM on permanent VCP after thyroidectomy.

METHODS

Retrospective review of prospective series of 1011 (1539 nerves-at-risk) patients undergoing thyroidectomy without (418, group 1) and with (583, group 2) IONM.

RESULTS

There were three recognized nerve injuries in group 1, vs one in group 2 (P = .3). There were no differences in overall VCP rates. However, patients in group 2 with immediate postoperative VCP had higher likelihood of full recovery than patients in group 1 (55 of 56 vs 23 of 29 patients, P = .01), and lower incidence of total permanent VCP (2 of 917 vs 9 of 647 patients, P = .01).

CONCLUSION

Among patients with immediate postoperative VCP after thyroidectomy, IONM is associated with a higher likelihood of regaining normal vocal function. This may be related to better identification of RLN branching in IONM cases.

Predictors and consequences of recurrent laryngeal nerve injury during open thyroidectomy: An American College of Surgeons National Surgical Quality Improvement Project database analysis

BACKGROUND

Recurrent laryngeal nerve (RLN) injury is a serious complication of thyroidectomy. The purpose of this study is to determine the predictors and consequences of RLN injury during thyroidectomy.

METHODS

A retrospective analysis was conducted using the ACS-NSQIP 2016-2017 main and thyroidectomy targeted procedure databases. Data was analyzed by multivariate logistic regression resulting in risk-adjusted odds ratios of RLN injury and morbidity/mortality.

RESULTS

Age ≥65, black race, neoplastic indication, total or subtotal thyroidectomy, concurrent neck surgery, operation time > median, hypoalbuminemia, and anemia were associated with RLN injury. Use of intraoperative nerve monitoring was associated with decreased RLN injuries. RLN injury is a risk factor for overall morbidity, hypocalcemia, hematoma, pulmonary morbidity, readmission, reoperation, and length of stay > median.

CONCLUSION

Several predictors of RLN injury during thyroidectomy are identified, while use of intraoperative nerve monitoring was associated with a decreased risk of RLN injury. RLN injury is associated increased postoperative complications.

Assessing National Utilization Trends and Outcomes of Robotic and Endoscopic Thyroidectomy in the United States

OBJECTIVE

We aimed to evaluate trends and outcomes of surgical approaches to thyroid surgery. We hypothesized that there have been changes over time in the utilization of approaches to thyroidectomy, including endoscopic, robotic, and open approaches, and that patient outcomes may differ between open surgery and endoscopic or robotic approaches.

STUDY DESIGN

Retrospective analysis.

SETTING

The National Cancer Database (NCDB) was queried between 2010 and 2016.

SUBJECTS AND METHODS

National cohort of patients. Descriptive statistics were performed using χ² test, Mann-Whitney U test, t test and analysis of variance. To investigate complication rates, patient matching was performed with subsequent analysis using simple and multivariable logistic regressions.

RESULTS

We identified 217,938 patients within the NCDB. While endoscopic thyroid surgery increased, relatively, in use over time (0.93% to 2.34% of cases in 2010 and 2016, respectively), robotic thyroid surgery started to decline relatively to other approaches from 2013 to 2016 (0.39% to 0.25% of cases, respectively). The endoscopic approach was performed more commonly than the robotic approach within individual facilities that have reported both procedures (P = .025). Robotic thyroid surgery was associated with increased risk of positive margins (P = .046), while endoscopic thyroid surgery was associated with a higher rate of unplanned hospital readmission (OR, 1.55; 95% CI, 1.09-2.22), longer inpatient stays (OR, 1.55; 95% CI, 1.19-2.02), and higher 90-day postoperative mortality (OR, 4.45; 95% CI, 1.58-12.6).

CONCLUSION

Endoscopic thyroid surgery has increased in utilization since 2004 but may have worse morbidity and mortality outcomes compared to open surgery.

Intraoperative nerve monitoring in thyroid surgery-shifting current paradigms

Over the past two decades, intraoperative neural monitoring (IONM) has matured into a powerful risk minimization tool. Meta-analyses of studies, most of which were limited by poor study designs and the sole use of intermittent nerve stimulation, failed to demonstrate superiority of IONM over anatomic recurrent laryngeal nerve (RLN) dissection in the absence of IONM. With the advent of continuous IONM (CIONM), intraoperative nerve electromyographic tracings, registered almost in real time during the operation, accurately predict postoperative vocal fold function when International Neural Monitoring Study Group quality standards are adhered to. CIONM aids in avoiding permanent traction-related nerve injury by urging surgeons to reverse harmful surgical maneuvers. CIONM also forms an integral part in the surgical concept of staged thyroidectomy. Delaying completion surgery on the other side until nerve function has recovered mitigates the risk of bilateral vocal fold palsy. CIONM has greatly furthered our understanding of functional RLN injury, enabling conception of effective risk minimization strategies tailored to the individual patient. The review summarizes the advances of continuous IONM technology that caused a quantum leap in risk minimization for thyroid surgery, shifting current paradigms.

Intraoperative nerve monitoring in endocrine surgery: prevalence and reasons for its use in Australia and New Zealand

BACKGROUND

Intraoperative nerve monitoring (IONM) has increasingly been used in thyroid surgery by general, endocrine and head and neck surgeons. The purpose of this paper was to explore the prevalence and reasons for the usage of IONM in endocrine surgery in Australia and New Zealand.

METHODS

A survey was sent to general surgeons registered with the Royal Australasian College of Surgeons involved in endocrine surgery and members of the Australian and New Zealand Endocrine Surgeons. Users were divided into surgeon type, area of work, hospital type and volume of surgery. These data were analysed with univariate and multivariate logistic regression models.

RESULTS

Significant differences in IONM usage levels were observed between endocrine and general surgeons, area of work and volume of surgery performed. Endocrine surgeons are significantly more likely to use IONM than general surgeons. Surgeons who work in tertiary hospitals are more likely to use IONM as compared to those working in district hospitals. Surgeons who perform less than 100 thyroidectomies were more likely to be users of IONM.

CONCLUSION

IONM is not routinely used in thyroid surgery in Australia and New Zealand. The main reasons for the use of IONM given in our study by routine users were to establish familiarity of equipment and medicolegal reasons. Selective users chose as the most common reasons, a documented pre-existing unilateral nerve paresis or a hostile surgical field. Non-users stated that there was conflicting evidence that it improves outcomes and increased costs.

Neural monitoring during H-type tracheoesophageal fistula division: A way to decrease recurrent laryngeal nerve injury?

Isolated tracheoesophageal fistula (TEF) is a rare condition with a previously reported high incidence of vocal cord paresis. A technique using recurrent laryngeal nerve monitoring is described as a strategy to potentially minimize the risk of vocal cord dysfunction in this patient population.

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.

Visual and electrophysiological identification of the external branch of superior laryngeal nerve in redo thyroid surgery compared with primary thyroid surgery

Purpose

Thyroid reoperations are surgically challenging because of significant anatomical variance. Visual and functional identification of the external branch of the superior laryngeal nerve (EBSLN) were studied in 2 groups of patients who underwent primary and redo thyroid surgery.

Methods

This study was conducted on 200 patients: 100 patients with redo and 100 patients with primary thyroid surgery. In addition to visual identification, nerve branches were functionally identified by intraoperative nerve monitoring (IONM). Visual, functional, and total identification rates of the EBSLN in both primary and redo surgery were determined and compared between the 2 groups.

Results

We attempted to identify 138 and 170 EBSLNs at risk in redo and primary surgery, respectively. Visual identification rates were 65.3% and 30.4% (P < 0.001) in primary and redo surgery groups, respectively. In total, 164 (96.5%) and 97 EBSLNs (70.3%) were identified in primary and redo surgery, respectively (P < 0.001), including the use of IONM. In primary surgery group, 53 nonvisualized EBSLNs of 164 identified nerves (32.3%) were determined by IONM alone. In redo surgery group, 55 of 97 identified nerves (56.7%) were determined by IONM alone (P < 0.001).

Conclusion

Both visual and total identification rates of the EBSLN are significantly decreased in reoperative thyroidectomy. IONM increases the total identification rate of the EBSLN in primary and redo thyroid surgery. Electrophysiological monitoring makes a substantial contribution to the identification of the EBSLN both in primary and especially in redo thyroid surgery.

Intraoperative neuromonitoring versus visual nerve identification for prevention of recurrent laryngeal nerve injury in adults undergoing thyroid surgery

BACKGROUND

Injuries to the recurrent inferior laryngeal nerve (RILN) remain one of the major post-operative complications after thyroid and parathyroid surgery. Damage to this nerve can result in a temporary or permanent palsy, which is associated with vocal cord paresis or paralysis. Visual identification of the RILN is a common procedure to prevent nerve injury during thyroid and parathyroid surgery. Recently, intraoperative neuromonitoring (IONM) has been introduced in order to facilitate the localisation of the nerves and to prevent their injury during surgery. IONM permits nerve identification using an electrode, where, in order to measure the nerve response, the electric field is converted to an acoustic signal.

OBJECTIVES

To assess the effects of IONM versus visual nerve identification for the prevention of RILN injury in adults undergoing thyroid surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, ICTRP Search Portal and ClinicalTrials.gov. The date of the last search of all databases was 21 August 2018. We did not apply any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing IONM nerve identification plus visual nerve identification versus visual nerve identification alone for prevention of RILN injury in adults undergoing thyroid surgery DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts for relevance. One review author carried out screening for inclusion, data extraction and 'Risk of bias' assessment and a second review author checked them. For dichotomous outcomes, we calculated risk ratios (RRs) with 95% confidence intervals (CIs). For continuous outcomes, we calculated mean differences (MDs) with 95% CIs. We assessed trials for certainty of the evidence using the GRADE instrument.

MAIN RESULTS

Five RCTs with 1558 participants (781 participants were randomly assigned to IONM and 777 to visual nerve identification only) met the inclusion criteria; two trials were performed in Poland and one trial each was performed in China, Korea and Turkey. Inclusion and exclusion criteria differed among trials: previous thyroid or parathyroid surgery was an exclusion criterion in three trials. In contrast, this was a specific inclusion criterion in another trial. Three trials had central neck compartment dissection or lateral neck dissection and Graves' disease as exclusion criteria. The mean duration of follow-up ranged from 6 to 12 months. The mean age of participants ranged between 41.7 years and 51.9 years.There was no firm evidence of an advantage or disadvantage comparing IONM with visual nerve identification only for permanent RILN palsy (RR 0.77, 95% CI 0.33 to 1.77; P = 0.54; 4 trials; 2895 nerves at risk; very low-certainty evidence) or transient RILN palsy (RR 0.62, 95% CI 0.35 to 1.08; P = 0.09; 4 trials; 2895 nerves at risk; very low-certainty evidence). None of the trials reported health-related quality of life. Transient hypoparathyroidism as an adverse event was not substantially different between intervention and comparator groups (RR 1.25; 95% CI 0.45 to 3.47; P = 0.66; 2 trials; 286 participants; very low-certainty evidence). Operative time was comparable between IONM and visual nerve monitoring alone (MD 5.5 minutes, 95% CI -0.7 to 11.8; P = 0.08; 3 trials; 1251 participants; very low-certainty evidence). Three of five included trials provided data on all-cause mortality: no deaths were reported. None of the trials reported socioeconomic effects. The evidence reported in this review was mostly of very low certainty, particularly because of risk of bias, a high degree of imprecision due to wide confidence intervals and substantial between-study heterogeneity.

AUTHORS' CONCLUSIONS

Results from this systematic review and meta-analysis indicate that there is currently no conclusive evidence for the superiority or inferiority of IONM over visual nerve identification only on any of the outcomes measured. Well-designed, executed, analysed and reported RCTs with a larger number of participants and longer follow-up, employing the latest IONM technology and applying new surgical techniques are needed.

Displacement of the Recurrent Laryngeal Nerve in Patients with Recurrent Goiter Undergoing Redo Thyroid Surgery

Thyroid reoperations are surgically challenging because of scarring and disturbances in the anatomy of the recurrent laryngeal nerve (RLN). This study was conducted on 49 patients who underwent redo surgery. 61 RLNs were identified and completely exposed. Their functional integrity was evaluated using intraoperative nerve monitoring (IONM). Indications for secondary surgery, anatomical changes secondary to recurrent goiter mass and prior surgery, and results of IONM were studied. Frequent indications for redo surgery were multinodular goiter (MNG) in 19 (38.8%) and results of cytology in 14 (28.5%) patients. The mean time interval between primary and redo thyroid surgery was 23.4 years. We laterally approached 41 (67.2%) thyroid lobes between the sternocleidomastoid and sternohyoid muscles. 16 (26.2%) RLNs were found to be adherent to the lateral surface of the corresponding thyroid lobe. The functional integrity of all RLNs was confirmed by IONM. The remnant thyroid tissue can then lead to goiter recurrence requiring secondary surgery after a long period of time. The indications for redo surgery were similar to primary cases. Lateral displacement of the RLN which is adherent to the lateral surface of recurrent goiter mass is common anatomic variation. Thyroid reoperations based on awareness of anatomical disturbances can be performed safely by an experienced surgeon with support of ancillary electrophysiological technology.

Complication Risk in Secondary Thyroid Surgery

Objectives

Secondary thyroid surgery is rare, compared with primary thyroid surgery. However, secondary surgery has a greater risk of complications due to the formation of scar tissue as well as increased fragility of the tissues following the previous surgery. Several surgical techniques and strategies have been recommended to decrease the complication rate associated with secondary surgery. The aim of this study was to evaluate the complication rate in patients who underwent secondary thyroid surgery using a lateral approach and intraoperative nerve monitoring (IONM).

Methods

The data of 44 patients who underwent secondary surgical intervention after thyroid surgery performed for benign or malignant thyroid disease (Group 1), and of 44 patients who underwent primary surgery (Group 2) were compared. Lobectomy patients with a histopathological result of malignant disease, whom were applied completion thyroidectomy were excluded from the study. Secondary surgery was performed using a lateral approach. Access was achieved between the anterior edge of the sternocleidomastoid muscle and the strap muscles. In primary surgery, the thyroid lodge was entered through the midline. Standard IONM was applied in all cases. Hypocalcemia was defined as a serum calcium level of ≤8 mg/dL within the first postoperative 48 hours, regardless of clinical symptoms. Transient and permanent recurrent laryngeal nerve paralysis was evaluated based on the number of nerves at risk. The lobectomy was considered to be high-risk with the presence of recurrence, Graves' disease, substernal goiter, and application of central dissection.

Results

The mean age of Group 1 and 2 was 49.9±14.1 years and 45±12.6 years , respectively (range: 22-90 years; p=0.69). Female patients constituted 90.9% (n=40) of the population in Group 1 and 75% (n=33) of the patient population in Group 2 (p=0.87). In Group 1, 11 (25%) patients, and 7 (15.9%) patients in Group 2 underwent surgical intervention due to the presence of a malignant disease (p=0.29). Bilateral intervention was applied in 26 (59.1%) patients in Group 1 and 28 (63.6%) patients in Group 2. The rate of transient and permanent hypocalcemia in Groups 1 and 2 was 34.1% (n=15) vs 22.5%, and 2.5% (n=1) vs 0%, respectively, without any significant intergroup difference (p=0.237, p=1). In Group 1, 71 lobes were operated on, and there were 72 in Group 2. All of the interventions in Group 1 (100%), and 31.9% (n=23) of those in Group 2 were high-risk, and there was a significant intergroup difference (p<0.0001). The rate of transient and permanent vocal cord paralysis were 4.2% (n=3) vs 2.8% (n=2) and 6.9 % (n=5) vs 0% in Groups 1 and 2, respectively (p=0.719; p=0.245).

Conclusion

When performed with a meticulous and attentive technique, secondary surgical intervention can be applied without increasing the incidence of permanent complications. Though there is substantial risk associated with all of these procedures, the rate of vocal cord paralysis was similar to that seen after primary intervention, and was thought to be related to surgical experience and technique, as well as the use of IONM.