Intraoperative nerve monitoring in thyroid surgery: analysis of United Kingdom registry of endocrine and thyroid surgery database

High-Precision Identification of Sensory and Motor Branches of the Recurrent Laryngeal Nerve Via Autofluorescence System in Thyroid Surgery

Recurrent laryngeal nerve (RLN) injury is a critical complication in thyroidectomy, with the severe sequelae of operation-related vocal cord palsies. The primary therapy following RLN injury includes voice therapy and surgical reintervention, both of which render subpar results paired with a long road to recovery. Despite the development of technical measures to prevent inadvertent operational injury of the RLN, its occurrence is still a concern. A newly developed handheld device with nerve autofluorescence technology has emerged as a visual aid tool for the intraoperative identification of nervous anatomical landmarks in thyroid surgery, showcasing promising initial findings. This study evaluates the efficacy of the aforementioned device in the intraoperative identification and differentiation of sensory and motor branches of the RLN. Sixteen patients undergoing thyroid surgery were included in this study, of which 16 RLNs and its branches were examined. Basic demographics, indication for thyroid surgery, and postoperative outcomes were identified. Multiple intraoperative images were analyzed through image processing software programs for the total number of nerves and branches, type of branch (e.g., sensory versus motor branches), near-ultraviolet (NUV) light intensity emitted by the nerve structures, and length and angular aperture of branches. The ability to prevent operation-related RLN injury was clinically evaluated at postoperative follow-up. Following analyses, no significant difference was observed between NUV light intensity (p=0.70) or structural length (p=0.18) between sensory and motor nerve branches of the RLN. This was further confirmed by fast Fourier transform (FFT) analyses and three-dimensional surface plots. No partial or total vocal cord palsies were recorded in the perioperative period, thus confirming the accuracy for intraoperative identification of the RLN and the preservation of structural integrity irrespective of surgical technique or type of branch (sensory or motor). Altogether, these findings highlight the potential of autofluorescence technology to enhance surgical precision, improve nerve preservation, and reduce the risk of nerve injury via safe surgical navigation in comparison to current intraoperative neuromonitoring systems limited to motor branch detection.

Utilization of recurrent laryngeal nerve monitoring during thyroid surgery in China: a point prevalence survey (2015-2023)

BACKGROUND

The survey aimed to elucidate the complete range of national practices, including all technical and non-technical aspects, as well as surgical stratification and maturation, of the use of intraoperative neuromonitoring (IONM) during thyroid surgery in China.

MATERIALS AND METHODS

Six national questionnaires, developed by the Chinese Neural Monitoring Study Group (CNMSG) between 2015 and 2023, were used to collect and analyze data regarding the clinical application, education, and scientific research related to IONM in Chinese medical institutions.

RESULTS

Among the surveyed hospitals, 45% reported an average annual surgical volume exceeding 3000 cases, with 82.5% performing more than 80% of the surgeries for malignant thyroid tumors. Additionally, 97.5% of the hospitals reported a less than 3% incidence of postoperative hoarseness with IONM. Statistical analysis from 2011 to 2015 found that the incidence of postoperative hoarseness decreased by 30% in 2013 compared with 2011, when the technology was introduced. Preoperative and postoperative laryngoscopies were routinely performed by 82.5% and 15% of the hospitals, respectively. For 65% of the hospitals, the publication of the Chinese edition of neuromonitoring guidelines in 2013 prompted the utilization of IONM technology. An average annual number of IONM applications exceeding 500 cases (18.5% the average volume) was reported by 80% of the hospitals, while 62.5% reported a cumulative number of applications greater than 5000 cases (47.1% the average cumulative volume). Regarding technical parameters, 75% of the hospitals reported an intraoperative V1 amplitude of greater than 500 µV, and 70% reported an intraoperative loss of signal (LOS) rate of less than 3%. 92.5% of the surveyed hospitals believed that IONM could help identify dissociated nerves, and 95% of the surveyed hospitals believed that IONM could reduce nerve damage. However, 72.5% of the respondents thought that cost was the main limitation. Furthermore, 67.5% of the hospitals reported that half of their thyroid surgical team members were trained in IONM, with 17.5% reporting that all team members were trained. Areas for reinforced training included IONM research methods and directions (72.5%) and analysis and treatment of abnormal EMG signals (72.5%). Research projects related to IONM were conducted by 42.5% of the hospitals, while 52.5% had published papers on neuromonitoring.

CONCLUSIONS

IONM was independently and incrementally associated with the annual surgical volume. This survey emphasized the importance of national collaboration and/or a registry for the uptake, consolidation, and development of CNMSG consensus.

Intraoperative neuromonitoring during thyroidectomy does not decrease vocal cord palsy risk, but the cumulative experience of the surgeon may

PURPOSE

To evaluate the influence of intraoperative neuromonitoring (IONM) on vocal cord palsy (VCP) rates and assess the temporal trends in VCP rates.

METHODS

The subjects of this retrospective study were patients who underwent thyroidectomy for thyroid cancer between March, 2014 and June, 2022, at a university hospital in Korea. We compared VCP rates between the non-IONM and IONM groups and analyzed the risk factors for VCP and VCP rates over time.

RESULTS

A total of 712 patients were included in the analysis. The rates of transient and permanent VCP did not differ significantly between the non-IONM and IONM groups. Transient VCP occurred in 4.6% and 4.3% patients (p = 0.878) and VCP was permanent in 0.7% and 0.4% patients (p = 0.607) in the non-IONM and IONM groups, respectively. Among the nerves at risk, transient damage occurred in 2.8% and 3.0% patients (p = 0.901), and permanent damage occurred in 0.4% and 0.3% (p = 0.688), respectively. Multivariate analysis revealed no significant risk factors for VCP. There was a significant decreasing trend in VCP rates over time as the cumulative number of cases increased (p = 0.017).

CONCLUSIONS

IONM did not reduce the risk of VCP significantly. However, the declining trend of VCP rates suggests that the surgeon's experience may mitigate VCP risk.

Delayed-onset vocal cord palsy after thyroidectomy occurring despite normal initial post-operative endoscopy

BACKGROUND

Recurrent laryngeal nerve (RLN) injury is a known complication of thyroidectomy. Most cases manifest immediately and are promptly recognized. Rarely, some patients experience delayed-onset vocal cord palsy. This can occur despite normal findings on intra-operative nerve monitoring and initial post-operative endoscopy. This can cause considerable distress for patients, and its incidence and prognosis should be recognized.

METHODOLOGY

We report seven patients experiencing delayed-onset RLN palsy (RLNP) after thyroidectomy. All had normal findings on pre-operative flexible nasoendoscopy (FNE), intra-operative nerve monitoring at conclusion of surgery, and initial post-operative FNE. All diagnoses of RLNP were confirmed on endoscopy. Serial FNE examinations were performed to evaluate recovery.

RESULTS

Of seven patients (43% male, median age 65 years), the median timing of delayed-onset RLNP was 12 (range 9-35) days. RLNP was diagnosed on the unilateral side of surgery in six out of seven patients (86%). All received conservative management, including referral to voice therapy. All seven patients recovered vocal cord function after a median duration of 24 weeks (range 8-52 weeks), and six within ~6 months (28 weeks). The incidence of this complication was 0.1% (among 6607 thyroidectomies).

CONCLUSION

We report the first Australian series of delayed-onset vocal cord palsy after thyroidectomy. We explore its prognosis, discussing different pathophysiological mechanisms and the timeframe for recovery compared to most other RLN injuries. This may assist recognition of a rare complication, reassure patients, and facilitate early intervention to improve a patient's quality of life.

Surgery for phaeochromocytomas and paragangliomas: Current practice in the United Kingdom

INTRODUCTION

There is wide variability in the perioperative management of phaeochromocytoma and paraganglioma (PPGL) in different centres. This study aimed to summarise the management of PPGLs as reported in the United Kingdom Registry for Endocrine and Thyroid Surgery (UKRETS) database and to determine current perioperative management of PPGLs by surveying UK clinicians.

METHODS

Data recorded on UKRETS from 2005 to 2021 were subjected to descriptive analyses. British Association of Endocrine and Thyroid Surgeons members were invited to participate in an open survey relating to the perioperative management of patients with PPGLs.

RESULTS

A total of 2,007 operations for PPGL from 49 participating centres were included. The median annual workload in each centre was four cases. Operations were performed predominantly laparoscopically (69%). The median length of stay (4 days) was the same in groups of surgeons stratified by volume. The survey had 29 respondents from 22 centres across the UK, and a formal protocol for perioperative management exists in 48% of the centres. Phenoxybenzamine (72%) was preferred for alpha-blockade. The practice of admitting patients for optimisation from 1 to 7 days before the day of surgery was common (62%). Central venous pressure and blood glucose monitoring were mentioned as routine intraoperative adjuncts by 72% of the responders.

CONCLUSIONS

There is significant variation in the workload and perioperative management of PPGLs in the UK. This is potentially detrimental to patient outcomes and a consensus document might be beneficial to harmonise practice across the UK.

Intraoperative Adjuncts in Thyroid Surgery

Thyroidectomy is relatively safe and often can be done as a minimally invasive procedure. Although they may be associated with a learning curve, thoughtful use of intraoperative adjuncts such as energy devices, recurrent laryngeal nerve monitoring, and parathyroid autofluorescence have the potential to make incremental improvements in the safety and efficiency of thyroid surgery. Perhaps many of these adjuncts may be of greatest benefit when used routinely by less experienced surgeons or selectively in higher-risk operations, although their adoption in practice continues to increase overall.

Patient-perceived dysphagia and voice change post thyroid surgery: a telephone questionnaire

OBJECTIVE

This study analyses the incidence of subjectively experienced dysphagia and voice change in post-thyroidectomy and parathyroidectomy patients without recurrent laryngeal nerve palsy.

METHODS

A total of 400 patients were invited to participate in a telephone questionnaire based on the Dysphagia Handicap Index and Voice Handicap Index. At 6-24 months following surgery, participants were divided into: post-thyroid surgery (total, hemi-, parathyroidectomy) groups and controls (other ENT procedures). A total of 254 responses were received (127 following thyroid surgery, 127 controls).

RESULTS

Twenty-two per cent of post-thyroidectomy patients had a Voice Handicap Index score of more than 3, compared to 15 per cent of parathyroid patients and 4 per cent of controls. The mean Dysphagia Handicap Index score for patients post thyroidectomy and hemi-thyroidectomy was 2.0. Parathyroidectomy patients had a mean Dysphagia Handicap Index score of 1.3, higher than controls at 1.0.

CONCLUSION

Dysphagia and voice alteration are common following thyroid surgery, even in the absence of recurrent laryngeal nerve injury. Both deficits occur more frequently following thyroid surgery than parathyroid surgery.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Nerve monitoring in endocrine surgery: Practice patterns differ among surgeons for parathyroidectomy and thyroidectomy

BACKGROUND

It is unknown whether intraoperative nerve monitoring is associated with reduced vocal cord dysfunction after parathyroidectomy. We aimed to investigate intraoperative nerve monitoring use among Collaborative Endocrine Surgery Quality Improvement Program surgeons and factors associated with vocal cord dysfunction after parathyroidectomy.

METHODS

Patients who underwent parathyroidectomy included in the Collaborative Endocrine Surgery Quality Improvement Program (2014-2022) were identified. The annual percent change in parathyroidectomies performed with intraoperative nerve monitoring was calculated using joinpoint regression. Multivariable logistic regression was used to compare outcomes between patients undergoing parathyroidectomy with/without intraoperative nerve monitoring. To compare surgeon-specific trends, Collaborative Endocrine Surgery Quality Improvement Program thyroidectomy and parathyroidectomy datasets (2014-2021) were combined. Parathyroidectomies performed by surgeons who used intraoperative nerve monitoring consistently in thyroidectomy were identified. Factors associated with intraoperative nerve monitoring were examined using multivariable logistic regression.

RESULTS

A total of 9,813 patients underwent parathyroidectomy. Intraoperative nerve monitoring was used in 49% of cases (n = 4,818). There was an increase in parathyroidectomies with intraoperative nerve monitoring from 2014 to 2018 (annual percent change 22.2, P = .01), followed by a plateau (2018-2022 annual percent change -0.66, P = .85). Few patients (0.44%, n = 43) developed vocal cord dysfunction. Vocal cord dysfunction was not associated with intraoperative nerve monitoring (adjusted odds ratio 0.92, P = .75). Whereas 41% (n = 56/138) of surgeons used intraoperative nerve monitoring routinely in parathyroidectomy, 65% (n = 90/138) used it routinely in thyroidectomy. Among surgeons who used intraoperative nerve monitoring routinely in thyroidectomy, only 57% used it routinely in parathyroidectomy; factors associated with intraoperative nerve monitoring during parathyroidectomy included reoperation (adjusted odds ratio 2.51, P < .01), secondary/tertiary hyperparathyroidism (adjusted odds ratio 1.42, P = .02), multiglandular disease (adjusted odds ratio 1.76, P < .001), and non-localized disease (adjusted odds ratio 1.65, P < .001).

CONCLUSION

Endocrine surgeons use intraoperative nerve monitoring selectively. Surgeons who routinely use intraoperative nerve monitoring during thyroidectomy are more likely to use it during parathyroidectomy. Future studies should determine who may benefit most from intraoperative nerve monitoring in parathyroidectomy.

Global scientific trends on thyroid disease in early 21st century: a bibliometric and visualized analysis

Background

Bibliometrics has been used to analyze the literature in the field of thyroid disease studies in the early 21st century, indicating the changes in current international study trends.

Methods

In this study, a bibliometric analysis of data retrieved from the Web of Science (WoS) database was conducted, and the publication trends and thematic evolution in the field of thyroid disease research from January 1, 2000, to November 16, 2022, were analyzed. A total of 69283 articles related to thyroid diseases were evaluated for their characteristics, including annual publication volume, countries, journals, institutions, authors, keywords, and references. VOSviewer was utilized to perform the analysis of co-authorship, co-citation, co-occurrence and descriptive.

Results

The annual publication volume of thyroid disease research literature showed a fluctuating upward trend from 2000 to 2021, exceeding 5,000 articles for the first time in 2021. The United States (16120 counts, 678255 cities) ranks first in terms of publication volume and citation. Thyroid (n=3201) and Journal of Clinical Endocrinology&Metabolism (n=140399) are the most prolific and cited journals, respectively. The organization with the highest publication volume and citation frequency is Harvard University (1011 counts, 59429 cities), Miyauchi Akira (n=422), Schlumberger, and Martin (n=24839) possess the highest publication volume and citation frequency, respectively. Co-occurrence analysis of 307 keywords with frequencies of more than 20 resulted in 6 clusters (1): Thyroid dysfunction and diseases (2); mechanism of occurrence and development of thyroid cancer (3); autoimmune thyroiditis (4); scope and postoperative management of thyroid surgery (5); fine needle aspiration of thyroid nodules (6); radioactive iodine therapy for thyroid cancer. Active monitoring, thermal ablation, Lenvatinib, and long noncoding RNA refer to the latest keywords. Discussing the six clusters helps scholars to determine the scope and direction of studies.

Conclusion

Over the past two decades, the literature related to thyroid diseases has increased year by year, with closer collaboration between countries, institutions, and authors. In this study, the global trends, research hotspots, emerging subjects, and basic knowledge of literature related to thyroid diseases were respectively elucidated, which will facilitate researchers in this field to seek better development.

Litigation in thyroid surgery: a pan-specialty review of National Health Service (UK) data

OBJECTIVE

Thyroid surgery carries risks that significantly impact patients. This paper describes the landscape of thyroid surgery related litigation claims in the National Health Service from April 2015 to April 2020, to establish learning points in order to improve patient care and minimise litigation risk.

METHODS

Data were requested from National Health Service Resolution and Hospital Episode Statistics. Claims were classified into operative and non-operative causes. Subspecialty information, incident details and claim costings were analysed.

RESULTS

Sixty claims were identified. Thirty-eight claims (63.3 per cent) were closed, with an average total claim cost of £68 816 and average damages paid of £36 349. Claims related to diagnostic issues were most common (n = 19); of claims associated with operative causes (n = 30), those relating to nerve injury were most common (n = 8), with issues of nerve monitoring and consent being cited.

CONCLUSION

Utilisation of well-established protocols will likely reduce litigation in thyroid surgery, as we move towards a landscape in which the patient journey is thoroughly scrutinised for targeted improvements.

The TOFr of 0.75 to 0.85 is the optimal timing for IONM during thyroid surgery: a prospective observational cohort study

BACKGROUD

Recurrent laryngeal nerve (RLN) injury is one of the serious complications of thyroid tumour surgery, surgical treatment of thyroid cancer requires careful consideration of the RLN and its impact on glottis function. There has been no unified standard for precise neuromuscular block monitoring to guide the monitoring of RLN in thyroid surgery. This study aimed to investigate the correlation between Train-of-four stabilization ratio (TOFr) and neural signal values of intraoperative neurophysiological monitoring (INOM) during thyroid operation, and further to determine the optimal timing for INOM during thyroid operation.

METHODS

Patients scheduled for thyroid tumour resection with INOM and RLN monitoring from April 2018 to July 2018 in our center were recruited. Electromyography (EMG) signals and corresponding TOFr were collected. All nerve stimulation data were included in group VR. Vagus nerve stimulation data were included in Subgroup V. RLN stimulation data were included in Subgroup R. The timing of recording was as follows: Vagus nerve EMG amplitude after opening the lateral space between the thyroid and carotid sheath and before the initiation of thyroid dissection, RLN EMG amplitude at first recognition, RLN EMG amplitude after complete thyroid dissection (Repeat three times), and Vagus nerve EMG amplitude after resection of the thyroid (Repeat three times). Correlation analysis of continuous variables was described by a scatter diagram. Pearson correlation analysis or Spearman correlation analysis was used for the two groups of variables.

RESULTS

Finally, 134 vagus nerve signals and 143 RLN signals were analysed after matching with TOFr. The EMG amplitude in the VR group and subgroups after nerve stimulation was positively correlated with TOFr (p < 0.05). In the VR, V and R group, the incidence of EMG ≥ 500 µV in the 0.75 < TOFr ≤ 0.85 interval was significantly higher than the 0 < TOFr ≤ 0.75 interval (P = 0.002, P = 0.013 and P = 0.029), and has no statistical difference compared to 0.85 < TOFr ≤ 0.95 interval (P > 0.05).

CONCLUSIONS

The EMG signals of the RLN and vagus nerve stimulation during thyroid surgery were positively correlated with TOFr. TOFr > 0.75 could reflect more than 50% of the effective nerve electrophysiological signals, 0.75 < TOFr ≤ 0.85 interval was the optimal timing for IONM during thyroid surgery.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR1800015797) Registered on 20/04/2018. https://www.chictr.org.cn .

Routine use of intraoperative nerve monitoring is associated with a reduced risk of vocal cord dysfunction after thyroid cancer surgery

BACKGROUND

The aim of this study was to investigate the associations between individual surgeon's intraoperative nerve monitoring (IONM) practice and factors associated with vocal cord (VC) dysfunction in patients with thyroid cancer undergoing thyroidectomy.

METHODS

Using Collaborative Endocrine Surgery Quality Improvement Program (CESQIP) 2014-21 data, multivariable logistic regression analyses investigated variables associated with short- and long-term VC-dysfunction, associations of routine use of IONM with postoperative outcomes, and patient characteristics associated with IONM use.

RESULTS

Among 5,446 patients (76.7% female, mean age 49 years), 68.5% had surgery by surgeons using IONM in ≥ 90% of cases (63% of surgeons, n = 73). Post-operative VC-dysfunction was diagnosed by laryngoscopy in 3.0% of patients in the short-term and 2.7% in the long-term. When surgeons routinely used IONM, the incidence of VC-dysfunction was 2.4% in the short-term and 2.2% in the long-term, compared to 4.4% and 3.7%, respectively, when surgeons did not routinely use IONM (p < 0.01). After adjustment, routine use of IONM was independently associated with reduced risk of short- (OR 0.48, p < 0.01) and long-term (OR 0.52, p < 0.01) VC-dysfunction, a lower risk of postoperative hypoparathyroidism in the short- (OR 0.67, p < 0.01) and long-term (OR 0.54, p < 0.01), and higher likelihood of same-day discharge (OR 2.03, p < 0.01). Extrathyroidal tumor extension and N1-stage were factors associated with postoperative VC-dysfunction in the short- (OR 3.12, p < 0.01; OR 1.92, p = 0.01, respectively) and long-term (OR 3.11, p < 0.01; OR 2.32, p < 0.01, respectively).

CONCLUSION

Routine use of IONM was independently associated with a lower risk of endocrine surgery-specific complications and greater likelihood of same-day discharge.

Visualization of the recurrent laryngeal nerve alone versus intraoperative nerve monitoring in primary thyroidectomy: a framework approach to a missing typology

INTRODUCTION

Surgical studies evaluating a device or technology in comparison to an established surgical technique should accurately report all the important components of the surgical technique in order to reduce the risk of intervention bias. In the debate of visualization of the recurrent laryngeal nerve alone (VONA) versus intraoperative nerve monitoring (IONM) during thyroidectomy, surgical technique plays a key role in both strategies. Our aim was to investigate whether the surgical technique was considered as a risk of intervention bias by relevant meta-analyses and reviews and if steps of surgical intervention were described in their included studies.

METHODS

We searched PUBMED, CENTRAL-Cochrane library, PROSPERO and GOOGLE for reviews and meta-analyses focusing on the comparison of IONM to VONA in primary open thyroidectomy. Τhen, primary studies were extracted from their reference lists. We developed a typology for surgical technique applied in primary studies and a framework approach for the evaluation of this typology by the meta-analyses and reviews.

RESULTS

Twelve meta-analyses, one review (388,252 nerves at risk), and 84 primary studies (128,720 patients) were included. Five meta-analyses considered the absence of typology regarding the surgical technique as a source of intervention bias; 48 primary studies (57.14%) provided information about at least one item of the typology components and only 1 for all of them.

DISCUSSION

Surgical technique of thyroidectomy in terms of a typology is underreported in studies and undervalued by meta-analyses comparing VONA to IONM. This missing typology should be reconsidered in the comparative evaluation of these two strategies.

Does Surgeon Volume Impact Morbidity Following Parathyroidectomy? A Study of 16,140 Parathyroidectomies from the UK Registry of Endocrine and Thyroid Surgery (UKRETS) Database

BACKGROUND

Outcomes in endocrine surgery have been shown to improve with surgeon volume. We aimed to study the effect of surgeon volume on morbidity following parathyroidectomy.

METHODS

UKRETS data from 2004 to 2019 was studied. Parathyroidectomies for primary hyperparathyroidism with complete data were included. Exclusion criteria were age <18 or >80 years; surgeons contributing <10 cases overall; and length of stay >28 days. Multivariable analysis was performed. Primary outcome was persistent hypercalcaemia; secondary outcomes were haemorrhage, length of stay, need for re-admission, post-operative hypocalcaemia, and need for calcium/vitamin D supplements to maintain eucalcaemia at 6 months.

RESULTS

153 surgeons undertook mean 22.5 (median 17, range 2-115) parathyroidectomies/year. Persistent hypercalcaemia affected 4.8% (776/16140) overall; 5.7% (71/1242) in surgeons undertaking < 10 cases/year; 5.1% (3339/6617) for 10-30 cases/year; 5.0% (270/5397) for 30-50 cases; and 3.3% (96/2884) for >50 cases/year. High-volume (>50 parathyroidectomies/year) surgeons operated 23.4% (809/3464) of negative localisation cases compared to 16.4% (2074/12676) of positive localisation cases. Persistent hypercalcaemia was almost twice as common in image negative (7.9%) compared to image-positive (4%) cases. Persistent hypercalcaemia was significantly more likely to occur in the low volume (<10 parathyroidectomies/year) group than high volume (>50 parathyroidectomies/year), regardless of image positivity (p = 0.0006). Surgeon volume significantly reduced persistent hypercalcaemia on multivariable analysis (OR = 0.878, 95%CI 0.842-0.914, p < 0.001), along with age, sex, and positive localisation. BNE and re-operation significantly increased persistent hypercalcaemia. Post-operative hypocalcaemia occurred in 3.2% (509/16040) and was reduced with increasing surgeon volume (OR = 0.951, 95%CI 0.910-0.993, p < 0.001). Haemorrhage and length of stay were not significantly associated with surgeon volume.

CONCLUSION

The incidence of persistent hypercalcaemia, post-operative hypocalcaemia, and persistent hypoparathyroidism decreased with increasing surgeon volume. The relative reduction in persistent hypercalcaemia with surgeon volume was similar in image negative and positive groups, but the absolute reduction was higher in image negative cases. Restricting image negative parathyroidectomy to high-volume surgeons could be considered.

Mapping complications in thyroid surgery: statistical data are useful for medico-legal management of a recurrent safety issue

Quality of care assessment is a crucial tool for patient safety implementation. Litigation relating to thyroid surgery is one of the most represented sectors also due to the continuous increase in the number of thyroid interventions. Given the incidence of the problem, the present study aims to outline an operational methodology for risk mapping and litigation management in thyroid surgery. The study was conducted through the analysis of data collected at Umberto I General Hospital in Rome from 2007 to 2018. All thyroid surgery claims were included and, subsequently, a descriptive statistical analysis of the categorical variables was performed with the representation of frequencies in absolute terms and as a percentage. The results obtained show that in 94% of cases (44 cases) the reported event consists of incorrect treatment. The most frequent adverse events were identified in unilateral or bilateral recurrent nerve lesions (31; 70%); incomplete removal of the thyroid gland (6; 14%), post-surgical hypoparathyroidism (4; 9%), aesthetic damage secondary to surgical scars (2; 5%), dental avulsion during intubation maneuvers (1; 2%). The experience derived from the risk mapping through management of thyroid claims proved it to be a reactive tool of considerable importance in clinical governance. The promotion of measures aimed at improving the satisfaction of some critical parameters identified in the litigation management activity such as adherence to the indications for surgery, the preoperative diagnostic path, and the adequacy of the surgical report allows to further implement the quality of care in the surgical treatment of thyroid pathology.

Thyroidectomy in Australia 2022: lessons from 21,000 consecutive cases

In this article, we aim to describe our modern-day approach to total thyroidectomy, detailing the subtle refinements of our technique, as it has evolved over three decades and 21 000 cases. Since Delbridge's seminal paper in 2003, the major changes to our approach include a retrograde approach to the recurrent laryngeal nerve that allows dissection of the distal RLN from fascial bands within the ligament of Berry before medialisation of the thyroid lobe. Routine use of intraoperative nerve monitoring systems has increased our awareness of temporary neuropraxia, facilitated a reduction in the risk of bilateral RLN palsy and improved our identification and preservation of the external branch of the superior laryngeal nerve. The increasing use of advanced energy devices has been associated with a reduction in post-operative haematoma rates. We adopt a low threshold to parathyroid auto-transplantation, unless all glands are assessed to be clearly not at risk, and routinely supplement patients with Caltrate in the immediate post-operative period to minimize the risk of symptomatic hypocalcaemia. Ultimately, when we reflect on the subtle refinements that have contributed to improved outcomes, the fundamental principles of exposure and dissection that have evolved over decades remain the basis of our surgical approach and must continue to do so.

A Surgeon-Centered Neuromuscular Block Protocol Improving Intraoperative Neuromonitoring Outcome of Thyroid Surgery

BACKGROUND

Neuromuscular blocking agents provide muscular relaxation for tracheal intubation and surgery. However, the degree of neuromuscular block may disturb neuromuscular transmission and lead to weak electromyography during intraoperative neuromonitoring. This study aimed to investigate a surgeon-friendly neuromuscular block degree titrated sugammadex protocol to maintain both intraoperative neuromonitoring quality and surgical relaxation during thyroid surgery.

METHODS

A total of 116 patients were enrolled into two groups and underwent elective thyroid surgery with intraoperative neuromonitoring. All patients followed a standardized intraoperative neuromonitoring protocol with continuous neuromuscular transmission monitoring and received 0.6 mg/kg rocuronium for tracheal intubation. Patients were allocated into two groups according to the degree of neuromuscular block when the anterior surface of the thyroid gland was exposed. The neuromuscular block degree was assessed by the train-of-four (TOF) count and ratio. Patients in group I received sugammadex 0.25 mg/kg for non-deep neuromuscular block degree (TOF count = 1~4). Patients in group II were administered sugammadex 0.5 mg/kg for deep neuromuscular block degree (TOF count = 0). The quality of the intraoperative neuromonitoring was measured using the V₁ electromyography (EMG) amplitude. An amplitude less than 500 μV and greater than 500 μV was defined as weak and satisfactory, respectively.

RESULTS

The quality of the intraoperative neuromonitoring was not different between groups I and II (satisfactory/weak: 75/1 vs. 38/2, P = 0.14). The quality of surgical relaxation was acceptable after sugammadex injection and showed no difference between groups [55/76 (72.3%) in group I vs. 33/40 (82.5%) in group II, P = 0.23].

CONCLUSIONS

This surgeon-centered sugammadex protocol guided by neuromuscular block degree (0.5 mg/kg for deep block and 0.25 mg/kg for others) showed comparably high intraoperative neuromonitoring quality and adequate surgical relaxation. The results expanded the practicality of sugammadex for precise neuromuscular block management during monitored thyroidectomy.

Clarifying optimal outcome measures in intermittent and continuous laryngeal neuromonitoring

BACKGROUND

Intraoperative neuromonitoring (IONM) techniques have evolved over the past decade into intermittent IONM (I-IONM) and continuous IONM (C-IONM) modes of application. Despite many prior publications on both types of IONM, there remains uncertainty about what outcomes should be measured for each form of IONM. The primary objective of this paper is to define categories of benefit for I-IONM/C-IONM and to clarify and standardize their reporting outcomes.

METHODS

Expert review consensus statement utilizing modified Delphi methodology.

RESULTS

I-IONM provides diagnosis, classification, and prevention of nerve injury through accurate and early nerve identification. C-IONM provides real-time information on nerve functional integrity and thus may prevent some types of nerve injury but cannot assist in nerve localization. Sudden mechanisms of nerve injury cannot be predicted or prevented by either technique.

CONCLUSIONS

I-IONM and C-IONM are complementary techniques. Future studies evaluating the utility of IONM should focus on outcomes that are appropriate to the type of IONM being utilized.

Optimization of electromyographic endotracheal tube electrode position by UEScope for monitored thyroidectomy

OBJECTIVE

Proper position of an electromyographic (EMG) endotracheal tube within the larynx plays a key role in functional electrophysiologic intraoperative neural monitoring (IONM) in thyroid surgery. The purpose of this study was to determine the feasibility of a portable video-assisted intubation device (UEScope) to verify the optimal placement of an EMG tube.

METHODS

A retrospective study enrolled 40 consecutive patients who underwent monitored thyroidectomies. After positioning the patient for surgery, an anesthesiologist performed tracheal intubation with UEScope and checked the position of the tube at the proper depth without rotation to the vocal cords. The main outcome measured was the proper EMG tube position, free from further adjustment. The secondary outcomes assessed were the percentage of available initial vagal stimulation (V1) signals.

RESULTS

All tracheal intubations were successful at first attempt. Proper EMG tube placement without position adjustment was found in 97.5% of the patients. Tube withdrawal was required in a male patient. All patients obtained detectable V1 signals; the lowest and median V1 amplitude was 485 and 767 μV as a reference value, respectively.

CONCLUSION

The UEScope is a valuable and reliable tool for placing an EMG tube and confirming its position during monitored thyroidectomy. In addition, further tube adjustment might be waived in most cases when the anesthesiologist placed the EMG tube after patient positioning for surgery. Routine use of video-assisted intubation devices is highly recommended.

LEVEL OF EVIDENCE

4.

Surgical Skills and Technological Advancements to Avoid Complications in Lateral Neck Dissection for Differentiated Thyroid Cancer

Neck dissection is a surgical procedure reserved for thyroid cancer cases with clinically evident lymphatic invasion. Although neck dissection is a reliable and safe procedure, it can determine a significant morbidity involving a variety of structures of nervous, vascular and endocrine typology. A careful pre-operative study is therefore essential to better plan surgery. Surgical experience, combined with accurate surgical preparation and merged with adequate and specific techniques, can certainly help reduce the percentage of complications. In recent years, however, technology has also proved to be useful. Its crucial role was already recognized in the safeguard of the integrity of the laryngeal nerve through neuro-monitoring, but new technologies are emerging to help the preservation also of the parathyroid glands and other structures, such as the thoracic duct. These surgical skills combined with the latest technological advancements, that allow us to reduce the incidence of complications after neck dissection for thyroid cancer, will be reported in the present article. This topic is of significant interest for the endocrine and metabolic surgeons' community.

The volume and outcome relationship for thyroidectomy in England

Purpose

The delivery of surgical care in England has seen a momentum towards centralisation within larger volume hospitals and surgical teams. The aim of this study was to investigate outcomes in England in relationship to hospital and surgeon annual volumes for total thyroidectomy.

Methods

Data were extracted from the Hospital Episodes Statistics (HES) database for England. A 6-year period (April 2012–March 2018 inclusive) for all adult admissions for thyroidectomy was used in the analysis. The primary outcome measure used was a length of hospital stay greater than 2 days or an emergency readmission within 30 days following surgery. This was used as a proxy for surgical complications. A multilevel modelling strategy was used to adjust for hierarchy and potentially confounding.

Results

Data for 22,823 total thyroidectomies across 144 hospital trusts were used for analysis. For total thyroidectomy, larger volume surgeons had reduced levels of post-surgical complications; length of stay > 2 and > 4 days; emergency readmission at 30 days; and hypoparathyroidism, vocal cord palsy, stridor, and tracheostomy at 1-year post-surgery. Larger hospital volume was associated with lower levels of emergency readmission at 30 days and hypoparathyroidism at 1 year.

Conclusions

There is significant correlation between surgeon volume and clinical outcome for total thyroidectomy. The relationship was approximately linear, and a low-volume threshold could not be defined.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-021-02223-8.

New Developments in Anterior Laryngeal Recording Technique During Neuromonitored Thyroid and Parathyroid Surgery

A recurrent laryngeal nerve (RLN) injury resulting in vocal fold paralysis and dysphonia remains a major source of morbidity after thyroid and parathyroid surgeries. Intraoperative neural monitoring (IONM) is increasingly accepted as an adjunct to the standard practice of visual RLN identification. Endotracheal tube (ET) surface recording electrode systems are now widely used for IONM; however, the major limitation of the clinical use of ET-based surface electrodes is the need to maintain constant contact between the electrodes and vocal folds during surgery to obtain a high-quality recording. An ET that is malpositioned during intubation or displaced during surgical manipulation can cause a false decrease or loss of electromyography (EMG) signal. Since it may be difficult to distinguish from an EMG change caused by a true RLN injury, a false loss or decrease in EMG signal may contribute to inappropriate surgical decision making. Therefore, researchers have investigated alternative electrode systems that circumvent common causes of poor accuracy in ET-based neuromonitoring. Recent experimental and clinical studies have confirmed the hypothesis that needle or adhesive surface recording electrodes attached to the thyroid cartilage (transcartilage and percutaneous recording) or attached to the overlying neck skin (transcutaneous recording) can provide functionality similar to that of ET-based electrodes, and these recording methods enable access to the EMG response of the vocalis muscle that originates from the inner surface of the thyroid cartilage. Studies also indicate that, during surgical manipulation of the trachea, transcartilage, percutaneous, and transcutaneous anterior laryngeal (AL) recording electrodes could be more stable than ET-based surface electrodes and could be equally accurate in depicting RLN stress during IONM. These findings show that these AL electrodes have potential applications in future designs of recording electrodes and support the use of IONM as a high-quality quantitative tool in thyroid and parathyroid surgery. This article reviews the major recent developments of newly emerging transcartilage, percutaneous, and transcutaneous AL recording techniques used in IONM and evaluates their contribution to improved voice outcomes in modern thyroid surgery.

Training Courses in Laryngeal Nerve Monitoring in Thyroid and Parathyroid Surgery- The INMSG Consensus Statement

Intraoperative neural monitoring (IONM) is now an integral aspect of thyroid surgery in many centers. Interest in IONM and the number of institutions that perform monitored thyroidectomies have increased throughout the world in recent years. For surgeons considering the introduction of IONM in their practice, specific training in IONM devices and procedures can substantially shorten the learning curve. The International Neural Monitoring Study Group (INMSG) has been at the forefront of IONM technology and procedural adoption since the introduction of neural monitoring in thyroid and parathyroid surgery. The purpose of this document is to define the INMSG consensus on essential elements of IONM training courses. Specifically, this document describes the minimum training required for teaching practical application of IONM and consensus views on key issues that must be addressed for the safe and reliable introduction of IONM in surgical practice. The intent of this publication is to provide societies, course directors, teaching institutions, and national organizations with a practical reference for developing IONM training programs. With these guidelines, IONM will be implemented optimally, to the ultimate benefit of the thyroid and parathyroid surgical patients.