Surgery for advanced neuroendocrine tumours of the small bowel: recommendations based on a consensus meeting of the European Society of Endocrine Surgeons (ESES).

BACKGROUND: Small bowel neuroendocrine tumours often present with locally advanced or metastatic disease. The aim of this paper is to provide evidence-based recommendations regarding (controversial) topics in the surgical management of advanced small bowel neuroendocrine tumours. METHODS: A working group of experts was formed by the European Society of Endocrine Surgeons. The group addressed 11 clinically relevant questions regarding surgery for advanced disease, including the benefit of primary tumour resection, the role of cytoreduction, the extent of lymph node clearance, and the management of an unknown primary tumour. A systematic literature search was performed in MEDLINE to identify papers addressing the research questions. Final recommendations were presented and voted upon by European Society of Endocrine Surgeons members at the European Society of Endocrine Surgeons Conference in Mainz in 2023. RESULTS: The literature review yielded 1223 papers, of which 84 were included. There were no randomized controlled trials to address any of the research questions and therefore conclusions were based on the available case series, cohort studies, and systematic reviews/meta-analyses of the available non-randomized studies. The proposed recommendations were scored by 38-51 members and rated 'strongly agree' or 'agree' by 64-96% of participants. CONCLUSION: This paper provides recommendations based on the best available evidence and expert opinion on the surgical management of locally advanced and metastatic small bowel neuroendocrine tumours.

Accuracy and diagnostic performance of the Bethesda system for reporting thyroid cytopathology in a tertiary endocrine surgical referral center in Belgium.

BACKGROUND: The Bethesda System for Reporting Thyroid Cytopathology is a commonly used classification for fine needle aspiration (FNA) cytology of suspicious thyroid nodules. The risk of malignancy (ROM) for each category has recently been analyzed in three international databases. This paper compares the diagnostic performance of the Bethesda classification in a high-volume referral center in Belgium. METHODS: All consecutive thyroid procedures were registered in a prospective database from January 2010 till August 2022. Patient and surgical characteristics, preoperative Bethesda categories, and postoperative pathology results were analyzed. RESULTS: Out of 2219 consecutive thyroid procedures, 1226 patients underwent preoperative FNA. Papillary thyroid cancer was the most prevalent malignancy (N = 119, 70.4%), followed by follicular (N = 17, 10.1%) and medullary thyroid cancer (N = 15, 8.9%). Micropapillary thyroid cancer was incidentally found in 46 (3.8%) patients. Bethesda categories I, II, III, IV, V, and VI, respectively, represented 250 (20.4%; ROM 4.4%), 546 (44.5%; ROM 3.8%), 96 (7.8%; ROM 20.8%), 231 (18.8%; ROM 15.2%), 62 (5.1%; ROM 72.6%), and 41 (3.3%; ROM 90.2%) patients. Overall ROM was 13.8%. An negative predictive value (NPV) of 96.2% was found. Overall specificity was 64.2% with a positive predictive value (PPV) of 31.9%. Diagnostic accuracy was 67.8%. Compared to international databases (CESQIP, EUROCRINE, and UKRETS), ROM in this study appeared lower for Bethesda category IV (15.2 vs. 26.7% and p = 0.612). CONCLUSION: Despite being validated in numerous studies, ROM based on preoperative FNA cytology classified according to the Bethesda classification may vary among surgical centers and countries as this study reveals a higher NPV and lower PPV.

Role of hospital and patient factors in the outcome of reoperations for primary hyperparathyroidism: a retrospective multicenter cohort study.

BACKGROUND: There are few data on outcomes after reintervention for persistent or recurrent primary hyperparathyroidism (PHPT). The authors hypothesized that the variation in outcomes at the hospital level after reoperation would be significant. After accounting for this variability, some patient-level clinical criteria could be identified to help inform treatment decisions in this patient population. The aim of this study was to determine whether there is significant variation in outcomes after reoperation for PHPT between hospitals (hospital-level analysis) and identify clinical factors (patient-level analysis) that influence postoperative outcomes. MATERIALS AND METHODS: This retrospective multicenter cohort study was performed using the Eurocrine registry. Data from 11 countries and 76 hospitals from January 2015 to October 2020 were extracted. A generalized linear mixed model was used to assess the variation in outcomes at the hospital level and to identify risk factors of postoperative outcomes at the patient level. The primary endpoint (textbook outcome) was achieved when all six of the following postoperative conditions were met: no hypocalcemia or persistent hypercalcemia, no laryngeal nerve injury, no negative exploration, no normal parathyroid gland only on histopathology, and no postoperative death. RESULTS: Among 13 593 patients who underwent parathyroidectomy for PHPT, 617 (4.5%) underwent reoperative parathyroidectomy. At follow-up, 231 patients (37.4%) were hypocalcemic, 346 (56.1%) were normocalcemic without treatment, and 40 (6.5%) had persistent hypercalcemia. Textbook outcomes were achieved in 321 (52.0%) patients. The hospital-level variation in textbook outcome rates was significant ( P <0.001), and this variation could explain 29.1% of the observed outcomes. The criterion that remained significant after controlling for inter-hospital variation was 'a single lesion on sestamibi scan or positron emission tomography (PET) imaging' (odds ratio 2.08, 95% confidence interval 1.24-3.48; P =0.005). CONCLUSION: Outcomes after reoperation are significantly associated with hospital-related factors. A 'single lesion observed on preoperative sestamibi scan or PET' appears relevant to select patients before reoperation.

Thyroid surgery in the elderly: a surgical cohort.

PURPOSE: The need for thyroid surgery in the elderly is rising due to an ageing population, the liberal use of imaging studies, and the increasing prevalence of thyroid nodules and cancer with age. Data on surgical outcomes in this population are scarce and conflicting, but essential to assess safety of short-stay surgery. This study aims to compare surgical outcomes by age. METHODS: All consecutive patients undergoing thyroid surgery from January 2010 to July 2021 in a large tertiary referral centre for endocrine surgery were included in this surgical cohort. The indication for surgery, surgical morbidity (hypocalcaemia, bleeding, recurrent laryngeal nerve (RLN) palsy), and length of hospital stay were assessed in three age groups (young: 18-64y, older: 65-74y, and the elderly: 75 years and older). RESULTS: A total of 2,030 patients (1,499 young, 370 older, and 161 elderly) were included. The indication for surgery was significantly different, with the main indications in the elderly being multinodular goitre (70.2% vs. 47.7% in young patients) and thyroid cancer (9.9% vs. 7.0%). Reintervention for bleeding was more often required in the older (4.6%) and the elderly (2.5%) patients (vs. 1.4%). There was no difference in the proportion of hypocalcaemia or RLN palsy. The length of hospital stay was significantly longer in the elderly (length of stay longer than one day 43.5% vs. 9.8%). CONCLUSION: Thyroid surgery in patients aged 75 years and older is a safe procedure with morbidity comparable to younger patients. However, the risk of reintervention for bleeding is higher, rendering ambulatory surgery not advisable. TRIAL REGISTRATION: Researchregistry6182 on October 29th 2020, retrospectively registered.

Posterior retroperitoneal versus transperitoneal laparoscopic adrenalectomy in adults: results from the EUROCRINE® surgical registry.

PURPOSE: This study aims to compare posterior retroperitoneal laparoscopic adrenalectomy (PRLA) and laparoscopic transperitoneal adrenalectomy (LTA) in adults using pan-European data as conflicting results have been published regarding length of hospital stay, institutional volume, and morbidity. METHODS: This retrospective cohort study analyzed data from the surgical registry EUROCRINE®. All patients undergoing PRLA and TLA for adrenal tumours and registered between 2015 and 2020 were included and compared for morbidity, length of hospital stay, and conversion to open surgery. RESULTS: A total of 2660 patients from 11 different countries and 69 different hospitals were analyzed and 1696 LTA were compared to 964 PRLA. Length of hospital stay was shorter after RPLA, with less patients (N = 434, 45.5%, vs N = 1094, 65.0%, p < 0.001) staying more than 2 days. In total, 96 patients (3.6%) developed a complication Clavien-Dindo grade 2 or higher. No statistical difference was found between both study groups. After propensity score matching, length of hospital stay was shorter after PRLA (> 2 days 45.2% vs 63.0%, p < 0.001). After multivariable logistic regression, factors associated with morbidity were age (OR 1.03), male sex (OR 1.52), and conversion to open surgery (OR 5.73). CONCLUSION: This study presents the largest retrospective observational analysis comparing LTA and PRLA. Our findings confirm the shorter length of hospital stay after PRLA. Both techniques are safe leading to comparable morbidity and conversion rates.

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.

Long-term outcome of surgical techniques for sporadic primary hyperparathyroidism in a tertiary referral center in Belgium.

PURPOSE: Surgery remains the only permanent treatment option for primary hyperparathyroidism (pHPT). To date, the number of long-term outcome studies of parathyroidectomy is limited. This study aims to compare different surgical approaches and evaluate the importance of preoperative localization imaging in the treatment of pHPT. METHODS: All 200 consecutive patients with a parathyroidectomy for sporadic pHPT without planned concomitant surgery between 09/2009 and 04/2021 in a Belgian tertiary referral hospital were enrolled. All patients underwent at least two preoperative localization imaging studies (neck ultrasound, CT, SPECT, and/or Sestamibi scintigraphy) of the parathyroid glands. The main outcomes were the (long-term) cured proportion and postoperative morbidity (hypocalcemia, recurrent laryngeal nerve palsy, return to theater for bleeding, and wound morbidity). RESULTS: Most patients were referred with concordant positive imaging (82%, n = 164). Only nine patients (4.5%) had double negative imaging, not revealing a possible adenoma. The remaining 27 (13.5%) were referred with discordant imaging. Parathyroidectomy was performed via traditional cervicotomy (30%), mini-open approach (39.5%), or endoscopic approach (30.5%). Morbidity was low with no persistent hypocalcemia, one return to theater for bleeding, and no 30-day mortality. In the concordant imaging population, 13 patients (8%) had multiglandular disease. Overall, 97.5% was considered cured. Long-term recurrence was 12% with a minimal follow-up of 5 years. CONCLUSION: This consecutive, single-surgeon, single-center cohort with extensive data collection and long-term follow-up confirms the safety and excellent cured proportions of minimally invasive parathyroidectomy. Disease recurrence becomes more important long after surgery.

Long-term survival of metastatic small intestine neuroendocrine tumors: a meta-analysis.

This meta-analysis aims to evaluate the long-term survival and prognostic factors in patients with metastatic small intestine neuroendocrine tumors (siNETs). Patients with siNETs usually present with advanced disease, limiting curative treatment options. The overall survival seems favorable compared to other cancers, but differences in terminology, lack of consistent coding, conflicting results from smaller cohorts, and recent developments of new treatment options make (reliable) survival data difficult to achieve. Nevertheless, accurate survival data are essential for many facets of health care. A systematic literature search was performed using MEDLINE®(PubMed), EMBASE®, Web of Science, and Cochrane Library up to June 30, 2021. Studies were included if the overall survival data in patients with metastatic siNETs were reported. The results were pooled in a random-effects meta-analysis and are reported as hazard ratios and 95% CIs. Subgroup analyses and meta-regression were performed to assess the observed heterogeneity and the impact of important prognostic factors. After screening 9065 abstracts, there were 23 studies, published between 1995 and 2021, that met the inclusion criteria, with a total of 8636 patients. The weighted 5- and 10-year overall survival was 67 and 37%, respectively. Meta-regression identified younger age and primary tumor resection to be associated with better prognosis. Subgroup analyses showed similar results. This study confirms that in an advanced, metastatic setting, the weighted 5- and 10-year overall survival reveal a favorable prognosis, improving over the last few decades. Meta-regression showed that age at diagnosis is an important prognostic factor.

Effect of primary tumour resection without curative intent in patients with metastatic neuroendocrine tumours of the small intestine and right colon: meta-analysis.

BACKGROUND: Patients with small intestinal neuroendocrine tumours (siNETs) usually present with advanced disease. Primary tumour resection without curative intent is controversial in patients with metastatic siNETs. The aim of this meta-analysis was to investigate survival after primary tumour resection without curative intent compared with no resection in patients with metastatic siNETs. METHODS: A systematic literature search was performed, using MEDLINE® (PubMed), Embase®, Web of Science, and the Cochrane Library up to 25 February 2021. Studies were included if survival after primary tumour resection versus no resection in patients with metastatic siNETs was reported. Results were pooled in a random-effects meta-analysis, and are reported as hazard ratios (HRs) with 95 per cent confidence intervals. Sensitivity analyses were undertaken to enable comment on the impact of important confounders. RESULTS: After screening 3659 abstracts, 16 studies, published between 1992 and 2021, met the inclusion criteria, with a total of 9428 patients. Thirteen studies reported HRs adjusted for important confounders and were included in the meta-analysis. Median overall survival was 112 (i.q.r. 82-134) months in the primary tumour resection group compared with 60 (74-88) months in the group without resection. Five-year overall survival rates were 74 (i.q.r. 67-77) and 44 (34-45) per cent respectively. Primary tumour resection was associated with improved survival compared with no resection (HR 0.55, 95 per cent c.i. 0.47 to 0.66). This effect remained in sensitivity analyses. CONCLUSION: Primary tumour resection is associated with increased survival in patients with advanced, metastatic siNETs, even after adjusting for important confounders.

Risk factors for postoperative morbidity after thyroid surgery in a PROSPECTIVE cohort of 1500 patients.

BACKGROUND: Postoperative hypocalcaemia, recurrent laryngeal nerve palsy and postoperative bleeding are the most frequent postoperative complications after thyroid surgery, and therefore often used as quality indicators of thyroid surgery. We aimed to assess postoperative morbidity in a high-volume endocrine surgery unit, and to detect which factors are associated with higher risks. METHODS: Prospective surgical cohort in a high-volume tertiary referral centre for endocrine surgery in xxx. The first 1500 patients operated with hemi or total thyroidectomy during 2010-2019 were included. Postoperative hypocalcaemia, recurrent laryngeal nerve palsy and postoperative bleeding were assessed in relation to pre- and peri-operative characteristics using multivariable logistic regression analyses, expressed as odds ratios and 95% confidence intervals. RESULTS: Overall, 1043 patients (69.5%) received a total thyroidectomy and 457 (30.5%) a hemithyroidectomy. Permanent hypocalcaemia occurred in 3.1%, permanent recurrent laryngeal nerve palsy in 1.8% and surgical reintervention for bleeding in 2.6%. Younger age, female sex and cancer were risk factors for permanent hypocalcaemia. No clear risk factors could be identified for permanent nerve palsy. Female sex, high body mass index and heavier thyroids were protective against postoperative bleeding after total thyroidectomy. CONCLUSIONS: Surgical experience in endocrine surgery seems beneficial for clinical outcomes and contributes to organizational efficiency. A low complication risk can be obtained by trained high-volume endocrine surgeons, yet the risk is not negligible.

Papillary thyroid carcinoma with hobnail features showing rapid progression and therapy resistance.

BACKGROUND: Hobnail variant of papillary thyroid carcinoma (HVPTC), also designated as a micropapillary variant, is a rare but aggressive variant of PTC, representing <2% of all PTC. It was adopted in the newest World Health Organization classification. HVPTC is strongly associated with higher mortality in comparison to classic PTC and a high propensity for disease progression. This paper aimed to investigate the clinical course, cytological and histopathological features, and mutational profile of the hobnail variant from a unique case. CASE REPORT: A case of a 38-year-old female patient with HVPTC is presented. Total thyroidectomy with central and bilateral, lateral lymphadenectomy was performed. The clinical course showed aggressive features, as lymph node metastasis and extrathyroidal extension were present at the presentation. Molecular and immunohistochemical features are addressed along with a review of the literature. DISCUSSION: The cytological examination of FNA was in consonance with published literature. The cells showed hobnail features in several segments of both thyroidal lobes on histological examination. The tumour displayed a typical BRAF mutation and Gly12Ala mutation in the KRAS gene, previously not associated with PTC. CONCLUSION: We aimed to highlight the aggressive, clinicopathological features of this high-risk variant. We emphasise the need to evaluate suspicious thyroid nodules as an adequate diagnosis can prevent delayed therapy. It directly impacts the tumour's stage and prognosis. In fine-needle aspiration cytology showing papillary architecture carcinomas, HVPTC has to be part of the differential diagnosis.

Superior Laryngeal Nerve Signal Attenuation Influences Voice Outcomes in Thyroid Surgery.

OBJECTIVES/HYPOTHESIS: The objective was to identify whether injury of the external branch of the superior laryngeal nerve (EBSLN) or changes in EBSLN parameters after dissection during thyroidectomies correlate with changes in voice quality postoperatively. STUDY DESIGN: Prospective multicenter case series. METHODS: A prospective multicenter study was conducted on patients undergoing thyroidectomies with intraoperative nerve monitoring. Electromyography waveforms of EBSLN stimulation before (S1) and after superior pole dissection (S2) were evaluated using endotracheal tube (ETT) and cricothyroid intramuscular (CTM) electrodes. Voice outcomes were assessed using Voice-Related Quality of Life Surveys and Voice Handicap Index. RESULTS: A total of 131 at-risk EBSLNs were evaluated in 80 patients. Two nerves showed loss of CTM twitch coupled with an absent S2 signal response. Complete EBSLN loss of signal was more likely with: 1) Cernea EBSLN anatomic classification Type 2B; 2) with a longer distance from the sternothyroid muscle insertion site; and 3) with larger lobar volumes (P < .05). Patients who experienced a more than 50% decrement in CTM amplitudes of S2 (n = 7) by CTM electrodes had a statistically significant decline in their voice outcomes compared to those who did not (n = 69) (P < .05). CONCLUSIONS: Patients experienced worse voice outcomes when at least one EBSLN response amplitude decreased by more than 50% after dissection when measured by CTM needle electrodes. CTM needle electrodes have an ability to measure finer amplitude changes compared to ETT electrodes, may represent a safe method to deduce subtle EBSLN injuries, and may serve to optimize voice outcomes during thyroidectomy. CTM needle electrodes are safe and tolerated well. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1436-1442, 2021.

Intra-operative recovery of preoperative vocal cord paralysis during hemithyroidectomy for benign thyroid disease: case report and review of the literature.

INTRODUCTION: Multinodular goiter associated with preoperative vocal cord palsy is usually indicative of invasive thyroid malignancy. However, benign thyroid disease may also lead to vocal cord paralysis. CASE REPORT: We present a case of a 63-year old woman with a two-month history of hoarseness, loss of vocal pitch, difficulties with swallowing and shortness of breath. Preoperative flexible fiberoptic laryngoscopy showed a left vocal cord paralysis. Left hemithyroidectomy with isthmectomy under intraoperative neuromonitoring for multinodular goiter was performed. Intra-operatively, both ipsilateral recurrent laryngeal nerve (RLN) and vagal nerve (VN) were identified and preserved. Follow-up laryngoscopy 5 weeks postoperatively showed complete recovery of the left vocal cord movement. DISCUSSION: Intuitively, surgeons may assume that preservation of a palsied RLN in patients with preexisting vocal cord paralysis is not meaningful. However, patients with RLN palsy associated with benign thyroid disease can experience full recovery after surgery. CONCLUSION: Multinodular goiter associated with preoperative vocal cord paralysis should be managed with extreme caution and use of intra-operative neuromonitoring. The existing probability of intra-operative recovery of a preoperative RLN palsy underlines the importance of preserving the affected RLN during surgery for benign thyroid disease.

Feasibility of Autofluorescence for Parathyroid Glands During Thyroid Surgery and the Risk of Hypocalcemia: First Results in Belgium and Review of the Literature.

Background. Post-operative hypocalcemia remains the most frequent complication after total thyroidectomy. Recently, autofluorescence imaging was introduced to detect parathyroid glands early during dissection. Aim. We aimed to check the feasibility of autofluorescence regarding the number of parathyroid glands visualised and the risk of post-operative hypocalcemia. Methods. In a prospectively gathered cohort of patients undergoing thyroid surgery, we describe the risk of hypocalcemia in relation to the number of parathyroid glands visualised during surgery (and the risk reported in the scientific literature) and the feasibility to obtain an autofluorescence of the parathyroid glands. Results. From 2010 to 2019, 1083 patients were referred for total thyroidectomy in our tertiary referral centre for endocrine surgery, of which, 40 consecutive cases were operated using autofluorescence. Among the autofluorescence group, 14 (35.0%) had all 4 parathyroid glands visualised, compared to 147 (14.1%) in the other patients, without differences in the number of parathyroid glands reimplanted. No permanent hypocalcemia occurred in the autofluorescence group and 17.5% temporary hypoparathyroidism, compared to 3.1% and 31.9% among the other patients, and 4% (95% confidence interval [CI] 3-5%) and 19% (95% CI 15-24%) in the literature. Conclusion. Autofluorescence imaging provides reliable real-time visualisation at any point during thyroid surgery and helps to identify the parathyroid glands before detection with the naked eye. To date, it cannot be used as a standard technique and does not replace meticulous dissection. To become a useful adjunct in peroperative parathyroid management, large multicentre studies need to establish a potential clinical benefit of this novel technique.

ENSAT registry-based randomized clinical trials for adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is an orphan disease lacking effective systemic treatment options. The low incidence of the disease and high cost of clinical trials are major obstacles in the search for improved treatment strategies. As a novel approach, registry-based clinical trials have been introduced in clinical research, so allowing for significant cost reduction, but without compromising scientific benefit. Herein, we describe how the European Network for the Study of Adrenal Tumours (ENSAT) could transform its current registry into one fit for a clinical trial infrastructure. The rationale to perform randomized registry-based trials in ACC is outlined including an analysis of relevant limitations and challenges. We summarize a survey on this concept among ENSAT members who expressed a strong interest in the concept and rated its scientific potential as high. Legal aspects, including ethical approval of registry-based randomization were identified as potential obstacles. Finally, we describe three potential randomized registry-based clinical trials in an adjuvant setting and for advanced disease with a high potential to be executed within the framework of an advanced ENSAT registry. Thus we, therefore, provide the basis for future registry-based trials for ACC patients. This could ultimately provide proof-of-principle of how to perform more effective randomized trials for an orphan disease.

Lateral neck cyst as initial presentation of thyroid malignancy.

INTRODUCTION: A mass in the lateral aspect of the neck may cause a diagnostic dilemma for the clinician. Cystic lateral neck masses in young adults are most often benign as the most frequent cause is a branchial cleft cyst. However, this may be a pitfall as such a cystic mass can be a first presentation of occult malignancy. CASE REPORT: Here we present a case of a 25-year-old female patient with a cystic mass in the right lateral neck. This lesion was eventually diagnosed as cystic degeneration within a metastatic invaded lymph node from papillary thyroid carcinoma. Total thyroidectomy with right central and lateral lymphadenectomy was performed. DISCUSSION: The correct diagnosis risked to be missed as the initial appearance was mimicking a benign branchial cleft cyst. CONCLUSION: We aimed to highlight the possibility of an underlying unsuspected thyroid carcinoma in young patients initially presenting with a neck mass mimicking the more common benign branchial cleft cyst. We underline the necessity of thoroughly examining suspected cysts as adequate diagnosis should avoid delayed treatment as it directly affects the tumor stage and prognosis.

New placement of recording electrodes on the thyroid cartilage in intra-operative neuromonitoring during thyroid surgery.

OBJECTIVE: During thyroid surgery, extreme caution is needed not to harm the recurrent laryngeal nerve and to avoid vocal cord palsy. Intra-operative neuromonitoring became increasingly popular as an adjunct to the gold standard of visual identification of the recurrent laryngeal nerve (RLN). Electromyographic (EMG) responses are normally recorded by electrodes attached to the endotracheal tube. Alteration in position can lead to false loss of signal. We developed thyroid cartilage electrodes that can be fixed directly onto the thyroid cartilage. STUDY DESIGN: Prospective clinical cohort METHODS: Thyroid surgery with intra-operative neuromonitoring using both endotracheal tube-based electrodes and thyroid cartilage electrodes was performed in 25 patients undergoing thyroid surgery. EMG data were collected and reported as median and interquartile ranges (IQR), and the results were compared with the x Wilcoxon signed-rank test for paired measurements. RESULTS: After stimulating vagal nerve (VN), recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN), significantly higher EMG amplitudes were measured before and after thyroid resection for the thyroid cartilage (TC) electrodes, in all comparisons except for the right VN. At the level of the left EBSLN, median amplitude of 560 mV (IQR 190-1050) before and 785 mV (IQR 405-3670) after resection was noted. At the level of the right EBSLN, median amplitude of 425 µV (IQR 257-698) before and 668 mV (IQR 310-1425) after resection was noted. Median amplitudes of 760 mV (IQR 440-1180) and 830 mV (IQR 480-1490) were noted at the left RLN, median amplitudes of 695 mV (IQR 405-1592) and 1078 mV (IQR 434-1895) were noted at the right RLN. CONCLUSION: Thyroid cartilage electrodes appear to be a feasible and reliable alternative for endotracheal electrodes.