International Survey on the Identification and Neural Monitoring of the EBSLN During Thyroidectomy

Transcription

1 The Laryngoscope VC 2015 The American Laryngological, Rhinological and Otological Society, Inc. International Survey on the Identification and Neural Monitoring of the EBSLN During Thyroidectomy Marcin Barczynski, MD, PhD; Gregory W. Randolph, MD; Claudio Cernea, MD, PhD; The International Neural Monitoring Study Group in Thyroid and Parathyroid Surgery Objectives/Hypothesis: Surgical management of the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy is complex. We hypothesized that there exist variations in surgical behaviors patterns in the management of the EBSLN during thyroidectomy. Study Design: A prospective Web-based anonymous survey ( Methods: The survey, consisting of 22 questions including surgeon demographics, laryngeal examination before and after surgery, and utilization of intraoperative neuromonitoring (IONM) for the management of the recurrent laryngeal nerve (RLN) and the EBSLN, was sent to 673 surgeons worldwide with known interest in thyroid surgery. Results: A total of 170/673 (25.3%) surgeons from five continents with low-volume (11.2%), moderate-volume (27.2%), and high-volume practices (61.5%) completed the survey. Laryngeal preoperative examination was performed by 94% of respondents. IONM was utilized in the RLN management by 95% of respondents. IONM was used for identification of the EBSLN by 26.3% of low-volume versus 68.4% of high-volume surgeons (P 5.004), and 93% of respondents felt EBSLN identification with IONM as necessary in voice professionals. Staged thyroidectomy was performed for benign disease by 89.5% of low-volume versus 63.2% of high-volume surgeons (P 5.031). Post thyroid surgery laryngeal examination was performed by 36.8% of low-volume versus 64.9% of high-volume surgeons (P 5.032). Conclusions: Laryngeal examination and IONM is used frequently. However, the exact pattern of utilization varies notably with demographic information. Generally, high-volume surgeons, those with otolaryngology background, and younger surgeons more commonly utilize IONM according to existing international neural monitoring study group guidelines. Prospective multicenter studies are needed to guide an evidence-based management of the EBSLN during thyroidectomy. Key Words: Thyroid surgery, external branch of the superior laryngeal nerve, intraoperative neural monitoring. Level of Evidence: NA Laryngoscope, 126: , 2016 INTRODUCTION Intraoperative neural monitoring (IONM) during thyroid surgery has gained widespread acceptance as an adjunct to the gold standard of visual identification of the recurrent laryngeal nerve (RLN). 1 Contrary to routine RLN dissection, most surgeons tend to avoid rather than routinely expose and identify the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy. 2 4 IONM has the potential to be utilized for identification of the EBSLN and functional assessment From the Department of Endocrine Surgery, Third Chair of General Surgery (M.B.), Jagiellonian University Medical College, Krakow, Poland; Department of Otology and Laryngology, Division of Thyroid and Parathyroid Surgery (G.W.R.), Massachusetts Eye and Ear Infirmary, Department of Surgery, Division of Surgical Oncology (G.W.R.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, U.S.A.; Department of Head and Neck Surgery (C.C.), University of Sao Paulo Medical School, Sao Paulo, Brazil Editor s te: This Manuscript was accepted for publication July 9, The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Marcin Barczynski, MD, Department of Endocrine Surgery, Third Chair of General Surgery, Jagiellonian University, Medical College, 37 Prądnicka Street, Krakow, Poland. marbar@mp.pl DOI: /lary of its integrity; therefore, IONM might contribute to voice preservation following thyroidectomy or parathyroidectomy. 5 9 The International Neural Monitoring Study Group (INMSG) has recently published a guideline statement to optimize clinical utility of this technique for the management of the EBSLN based on available evidence and consensus of experts. 10 However, worldwide trends and variability in the management of this nerve have not been previously explored. The aim of this study was to define patterns of surgical behaviors in a group of surgeons attending current endocrine surgical thyroid programs in the management of the EBSLN during thyroidectomy, with special emphasis put on utilization of IONM. MATERIALS AND METHODS The Web-based anonymous survey ( com) was sent in May 2014 as an invitation to 673 surgeons worldwide with known interest in thyroid surgery drawn from the rosters of several international endocrine surgical courses from approximately 2011 through The survey consisted of 22 questions, which are listed in Table I. Responses were exported to an Excel file (Microsoft Corp., Redmond, WA) and analyzed statistically using MedCalc version 13 (MedCalc Software bvba, Ostend, Belgium). Responses were stratified to the demographic characteristics of the surgeons and analyzed to 285

2 TABLE I. Questions Used in This Survey.. Question Possible Answers Q1 What is your age? Below to to to to or older Q2 Where do you practice? Africa Asia Australia Europe rth America South America Q3 What is your specialty? Endocrine surgeon General surgeon Head and neck surgeon ENT specialist Specialist in surgical oncology Other Q4 Which best describes your primary practice setting? Community nonacademic center Academic center Private practice Q5 How many thyroid operation do you perform each year? < >200 Q6 Which of the following best describes your approach to laryngeal examination before thyroid surgery? Routinely performed on all patients Performed on selected patients Never performed Q7 What do you think is the main use(s) of laryngeal nerve monitoring? Select all that apply. Medicolegal protection I believe it is helpful in the management of the nerve I believe it is helpful in reducing permanent RLN injury I believe it is helpful in reducing temporary RLN injury Patient reassurance Surgeon reassurance Training purposes I think it has no use Q8 Do you use neural monitoring during thyroidectomy for the RLN identification?, in all operations, in the majority of operations, only in high-risk operations, I used it several times but abandoned, I have never tried Q9 In what situations do you use IONM? Select all that apply. Substernal goiter Thyroid cancer Preoperative identification of vocal fold paralysis Reoperative cases Patient has normal voice but reports hoarseness Patient requests nerve monitoring Goiter Central neck dissection Graves disease Preoperative dysphonia 286

3 TABLE I. (Continued). Question Possible Answers Q10 Which method of IONM do you use? Select all that apply. Palpation of contraction of the posterior cricoarytenoid muscle with stimulation of the RLN (laryngeal twitch response) A regular endotracheal tube with EMG adhesive applied Prefabricated EMG endotracheal tube Continuous nerve stimulation via a probe placed on the vagus nerve (continuous vagal monitoring) Intramuscular needle electrodes placed through the cricothyroid ligament Q11 Do you stimulate the vagus nerve at the beginning of the procedure (prior to mobilizing the thyroid)? Always More than 50% of the time Less than 50% of the time Never Q12 Do you stimulate the vagus nerve after completing a lobectomy? Always More than 50% of the time Less than 50% of the time Never Q13 While performing a total thyroidectomy for thyroid cancer on a patient with normal preoperative vocal cord function, you have what you perceive as a true loss of signal when stimulating the recurrent nerve on the first side. There is no visible injury to the nerve. How would you proceed? Continue as routine with the second side Perform a subtotal lobectomy on the second side to minimize risk of contralateral nerve injury Do not perform contralateral lobectomy at that time consider staged procedure Q14 While performing a total thyroidectomy for benign thyroid disease Continue as routine with the second side on a patient with normal preoperative vocal cord func- tion, you have what you perceive as a true loss of signal Perform a subtotal lobectomy on the second side to minimize risk of contralateral nerve injury when stimulating the recurrent nerve on the first side. There is no visible injury to the nerve. How would you proceed? Do not perform contralateral lobectomy at that time consider staged procedure Q15 Do you use neural monitoring for EBSLN identification?, in all operations, in the majority of operations, only in high-risk operations, I used it several times but abandoned, I have never tried Q16 In what situations do you require EBSLN identification with neural monitoring? Select all that apply. In a patient with a short neck In case of a big lump in the superior thyroid pole In a case of a big goiter In voice professionals Q17 When using neural monitoring for the identification of the EBSLN, do you assess cricothyroid muscle twitch? I do not use IONM for the EBSLN identification Q18 When using neural monitoring for the identification of the EBSLN, do you assess glottis endotracheal tube EMG? I do not use IONM for the EBSLN identification Q19 Which of the following best describes your approach to laryngeal examination after thyroid surgery? Routinely performed on all patients Performed on selected patients Never perform Q20 Did you experience postoperative voice changes in patients with "normal" vocal fold mobility at laryngoscopy? Q21 Are you familiar with the EBSLN neural monitoring during thyroid and parathyroid surgery INMSG standards guideline statement published in Laryngoscope 2013;123(suppl 4):S1 S14 (doi: /lary.24301)? Q22 Would you be willing to take part in the future in a prospective, multicenter study focused on neural monitoring of the EBSLN during thyroidectomy? EBSLN 5 external branch of the superior laryngeal nerve; EMG 5 electromyography; ENT 5ear, nose, and throat; INMSG 5 International Neural Monitoring Study Group; IONM 5 intraoperative neural monitoring, RLN 5 recurrent laryngeal nerve. 287

4 TABLE II. Baseline Characteristics of the Respondents of This Survey. Survey. (%) Sent to/responded 673 (100)/ 170 (25.3) Responses by continent Europe 78 (46.2) rth America 31 (18.3) Asia 27 (16.0) Australia 24 (14.2) South America 9 (5.3) Responses by specialty Endocrine surgeons 119 (70.4) General surgeons 20 (11.8) Head and neck surgeons 16 (9.5) Specialist in surgical oncology 8 (4.7) ENT specialist 6 (3.6) Responses by practice Academic center 127 (75.1) Private practice 28 (16.6) Community/nonacademic center 14 (8.3) Responses by personal thyroid surgical volume High volume (>100 operations per year)* 104 (61.5) Moderate volume ( operations per year) 46 (27.2) Low volume (<50 operations per year) 19 (11.2) *Among high-volume surgeons, 57 (33.5%) individuals performed more than 200 operations per year and were termed the highest-volume surgeons ENT 5ear, nose, and throat. identify differences in the management of the RLN and EBSLN. Data were presented as categorical values and corresponding percentage, and v 2 test was used to test relevance of observed differences between the groups. RESULTS A total of 170/673 (25.3%) respondents from five continents completed the survey. Baseline characteristics of respondents of this survey are shown in Table II. Preoperative laryngeal examination was performed on some or all patients by 99% of respondents. Approach to pre- and postoperative laryngeal examination is summarized in Table III. In our survey, neural monitoring was utilized in some or all cases by over 90% of respondents. Use of IONM for RLN identification and monitoring is summarized in Table IV. A prefabricated electromyographic (EMG) endotracheal tube with superficial electrodes was used by 111/161 (68.9%) surgeons, followed by a regular endotracheal tube with adhesive EMG superficial electrodes by 49/161 (30.4%), palpation of contraction of the posterior cricoarytenoid muscle with stimulation of the RLN by 30/161 (18.6%), and intramuscular needle electrodes placed through the cricothyroid ligament by 8/161 (5.0%). In addition, use of continuous vagal nerve monitoring was reported by 34/161 (21.1%) surgeons, whereas 9/170 (5.3%) respondents skipped this question. Standard practice of stimulation of the vagus nerve at the TABLE III. Approach to Pre- and Postoperative Laryngeal Examination. Question. (%) Laryngeal examination before surgery 169 (99.4) Routinely performed on all patients 104 (61.0) Performed on selected patients 65 (38.5) Never done 1 (0.6) Laryngeal examination after surgery 169 (99.4) Routinely performed on all patients 83 (49.1) Performed on selected patients 85 (50.3) Never done 1 (0.6) Postoperative voice changes in patients with normal vocal folds mobility after surgery I have seen cases like this 141 (83.4) I have never seen 28 (16.6) beginning of procedure was reported by 86/164 (51.8%) surgeons, whereas 12/164 (7.3%) declared doing it more frequently than 50% of the time, 39/164 (23.8%) less than 50% of the time, 28/164 (17.1%) never, and 6/170 TABLE IV. Use of IONM for RLN Identification and Monitoring. Question (%) Main use of IONM (n 5 170) Management of the nerve 117 (69.2) Surgeon s reassurance 83 (49.1) Training purposes 81 (47.9) Medicolegal protection 74 (43.8) Reducing permanent laryngeal nerve injury 73 (43.2) Reducing temporary laryngeal nerve injury 51 (30.2) Patient s reassurance 43 (25.4) use 8 (4.8) Use of IONM for RLN identification (n 5 170) Routinely in all operations 71 (42.0) In the majority but not all operations 25 (14.8) Only in high-risk thyroid operations 57 (33.7) Used it several times but abandoned 9 (5.3) Never tried 7 (4.1) Use of IONM for RLN monitoring in different clinical situations (n 5 161)* Reoperative cases 154 (95.7) Surgery for thyroid cancer 126 (78.3) Surgery for substernal goiter 113 (70.2) During central neck clearance 112 (69.6) In case of preoperative vocal fold paralysis 107 (66.5) Surgery for Graves disease 96 (59.6) Patient requests to use nerve monitor 86 (53.4) In case of preoperative dysphonia 85 (52.8) Operation for toxic goiter 81 (50.3) rmal voice but patient reports hoarseness 78 (48.4) *Multiple choice answer was possible. IONM 5 intraoperative neural monitoring, RLN 5 recurrent laryngeal nerve. 288

5 (3.5%) skipped this question. Stimulation of the vagus nerve after completing the lobectomy was reported to be always done by 86/163 (72.8%) surgeons, and more frequently than 50% of the time by 13/163 (8.0%), whereas 41/163 (25.2%) declared doing it less than 50% of the time, 21/163 (14.1%) never did it, and 7/170 (4.1%) skipped this question. While performing a total thyroidectomy for thyroid cancer on a patient with normal preoperative vocal cord function, in case of a true loss of signal when stimulating the RLN on the first side and no visible injury to the nerve, 85/162 (52.5%) surgeons would continue as routine with the second side, 9/162 (5.6%) would perform a subtotal lobectomy on the second side to minimize risk of contralateral nerve injury, 68/162 (42.0%) would not perform contralateral lobectomy at that time and would consider staged procedure, and 8/170 (4.7%) respondents skipped this question. On the other hand, while performing a total thyroidectomy for benign thyroid disease on a patient with normal preoperative vocal cord function, in case of a true loss of signal when stimulating the RLN on the first side and no visible injury to the nerve, 109/162 (67.3%) surgeons would not perform contralateral lobectomy at that time and would consider staged procedure, 17/162 (10.5%) would perform a subtotal lobectomy on the second side to minimize risk of contralateral nerve injury, 36/162 (22.2%) would continue as routine with the second side, and 8/170 (4.7%) skipped this question. Use of IONM for the EBSLN identification and monitoring is summarized in Table V. As many as 91/ 170 (53.8%) respondents were familiar with the EBSLN Neural Monitoring During Thyroid and Parathyroid Surgery INMSG Standards Guideline Statement. Interestingly, 142/170 (84.0%) respondents expressed their interest to take part in the future in a prospective, multicenter study focused on IONM of the EBSLN during thyroidectomy. Overall, IONM was used for identification of the RLN in some or all operations by 17/19 (89.5%) lowvolume surgeons, 41/46 (89.1%) moderate-volume surgeons, and 95/104 (91.3%) high-volume surgeons (P 5.221). It is of interest to note that IONM was utilized routinely in all thyroid operations for the identification of the RLN by 38/83 (45.8%) of respondents performing routine postoperative laryngoscopy, whereas it was utilized by 20/85 (23.5%) respondents using postoperative laryngoscopy on selected patients (P 5.002). However, difference in routine utilization of IONM for the identification of the EBSLN between respondents performing postoperative laryngoscopy on a routine versus select basis was not significant (17/38 [20.5%] vs. 11/ 85 [12.9%], P 5.189). Routine use of IONM for the RLN identification was declared by 34/70 (48.6%) respondents aged 44 years or younger versus 36/99 (36.4%) respondents aged 45 years or older (P 5.112), whereas the corresponding values for the EBSLN identification were 10/70 (14.3%) versus 16/99 (16.2%), respectively (P 5.739). Similarly, routine use of IONM for RLN identification was declared by 9/19 (47.4%) low-volume respondents versus 47/104 (45.2%) high-volume respondents (P 5.860), whereas the corresponding values for EBSLN TABLE V. Use of IONM for EBSLN Identification and Monitoring. Question. (%) Use of IONM for EBSLN identification (n 5 165) Routinely in all operations 27 (16.4) In the majority but not all operations 24 (14.6) Only in high-risk operations 31 (18.8) Used it several times but abandoned 27 (16.4) I have never tried 56 (34.0) Use of IONM for the EBSLN identification in different clinical situations (n 5 129)* For voice professionals 120 (93.0) In case of a big lump within the 66 (51.2) superior thyroid pole In a case of a big goiter 54 (41.9) In a patient with a short neck 40 (31.0) Utilization of cricothyroid muscle twitch assessment (n 5 156) 81 (51.9) 13 (8.3) Do not use IONM for the EBSLN identification 62 (39.7) Utilization of glottis endotracheal tube EMG assessment (n 5 158) 56 (36.4) 39 (24.7) Do not use IONM for the EBLSN identification 63 (39.9) *Multiple choice answer was possible EBSLN 5 external branch of the superior laryngeal nerve; EMG 5 electromyographic; IONM 5 intraoperative neural monitoring. identification were 1/19 (5.3%) versus 19/104 (18.3%), respectively (P 5.157). However, when responses were further analyzed stratified to the surgical volume, several significant differences were identified. IONM was used for identification of the EBSLN in all or some cases by 5/19 (26.3%) low-volume versus 39/57 (68.4%) highest-volume surgeons (performing more than 200 thyroid operation per year) based on the cricothyroid muscle twitch assessment (P 5.004), and 3/16 (15.8%) low-volume versus 35/ 57 (61.4%) highest-volume surgeons based on the assessment of glottis endotracheal tube EMG (P <.001). Eight of nineteen (42.1%) low-volume surgeons versus 39/57 (68.4%) highest-volume surgeons were familiar with the EBSLN Neural Monitoring Guideline Statement (P 5.041). Endocrine surgeons were less frequently familiar with the guideline than other specialties (63/ 119, 52.9% vs 35/50, 70.0%; P 5.040). After loss of signal, staged thyroidectomy was performed for benign thyroid disease by 17/19 (89.5%) low-volume versus 36/57 (63.2%) highest-volume surgeons (P 5.031). Laryngeal examination after thyroid surgery was routinely performed by 7/19 (36.8%) low-volume versus 37/57 (64.9%) highest-volume surgeons (P 5.032). DISCUSSION The INMSG has defined standards for both RLN and EBSLN neural monitoring. 1,10,11 Accurate and 289

6 uniform neural monitoring depends on adherence to these guidelines. 11 Intraoperative nerve monitoring of the EBSLN aids in EBSLN identification and provides electroneuromyographic information in 80% of cases when using standard EMG tubes. 7,12 However, utilization of a novel endotracheal tube (NIM TriVantage tube; Medtronic, Jacksonville, FL) allows for quantifiable EBSLN EMG activity in 100% of cases. 13,14 Despite growing surgical awareness worldwide as to the potential benefits of IONM for voice preservation, surgical behaviors in the management of the RLN and EBSLN during thyroidectomy are still poorly recognized. Most surgeons tend to avoid the EBSLN exposure rather than identify the nerve, and prevalence of utilization of IONM technique to assist in the identification of the EBSLN has never been explored in a worldwide survey. 4,10 In addition, the relationship of using nerve monitoring for the RLN and EBSLN and its relationship to patterns of laryngeal examination have not been previously reported. Hence, this challenge was undertaken by the INMSG, and as shown by outcomes of this survey, many aspects of EBSLN management during thyroidectomy differ between surgeons of different surgical volumes, working at different institutions/locations, and with different training backgrounds. Our response rate was within the existing range for similar studies using organization-based surveys. 15,16 We felt that using course rosters would allow a more robust random sample of surgeons who are in the midst of educational selfmotivated initiatives than by assessing surgeons through organizational affiliations. Utilization of IONM to identify the nerve and test its function intraoperatively is dependent on individual surgical preferences. We found that laryngeal examination is performed by our sample in some or all patients in nearly 100% of respondents with routine preoperative laryngeal examination occurring in over 60% of patients, being more common in high-volume surgical settings. Survey respondents performed neural monitoring in some or all of their cases at just over 90%, with the dominant reason being that neural monitoring assisted with RLN management (noted by approximately 70% of respondents). A range of varying equipment options were employed, but most common was the prefabricated neural monitoring tube. The application of IONM to the EBSLN seems to be lagging in RLN application. It was of interest to note that the technique of cricothyroid muscle twitch was used by approximately 50% of respondents. As many as 48% of respondents noted that in some or all of their cases monitoring was utilized for the EBSLN. The technique of cricothyroid muscle twitch and EBSLN glottis waveform was more commonly utilized by higher-volume surgeons. The respondents in 93% of cases suggesting neural monitoring had utility in patients undergoing surgery who were professional voice users/singers. High-volume surgeons, those with an otolaryngology background, at younger age, and utilizing routinely postoperative laryngoscopy were more likely to utilize IONM during thyroidectomy. Importantly, higher-volume surgeons were also more likely to apply neural monitoring for the EBSLN and expressed greater familiarity with neural monitoring guidelines. Interestingly, although a substantial percent of surgeons would stage patients in the setting of loss of signal, high-volume surgeons were less likely to stage patients in the setting of loss of signal then lower-volume surgeons. Despite the overwhelming acceptance of neural monitoring for the RLN and EBSLN in our survey population, strict adherence to published guidelines is still nascent, with only 51% performing routine beginning of surgery vagal stimulation and only 72% performing postlobectomy vagal stimulation. Neural monitoring data are clearly significantly being incorporated into surgical strategy in a high percentage of cases. Staging or altering the contralateral procedure extent was even recommended by 48% of respondents in the setting of malignancy and 77% in the setting of the benign diagnosis. Similar data have been reported in surveys focused on the assessment of IONM of the RLNs during thyroidectomy. Singer et al. queried head and neck surgeons (members of the American Head and Neck Society) regarding their attitudes toward IONM during thyroidectomy. 15 Information was anonymously collected on participants training history, practice setting, years of experience, and annual volume of thyroid and parathyroid surgeries. Participants use of IONM and their beliefs regarding possible benefits were assessed. One hundred seventy surveys were completed (18% response rate). Of respondents, 65% use IONM in at least some thyroid and parathyroid cases, 37% always, and 28% sometimes. The most commonly cited reasons for IONM use were "medicolegal protection" and "increased confidence." Comparing otolaryngologists to general surgeons, 43% versus 17% (P 5.016) always use IONM, 27% versus 36% sometimes use monitoring, and 30% versus 47% never use monitoring, respectively. Younger surgeons were more likely to use IONM. Thus, authors concluded that IONM use has become more widespread, and if this trend continues, IONM may eventually become the standard of care among head and neck surgeons. 15 Ho et al. analyzed trends in IONM for thyroid and parathyroid surgery among otolaryngologists (OTO- HNS) and general surgeons (GS). 16 That study was a multi-institution survey of 103 otolaryngology and 103 affiliated GS programs in the United States. Two hundred six surveys were sent to OTO-HNS and GS academic program directors, with a response rate of 44.7%. Of those who performed thyroid surgery, 80.6% of OTO- HNS and 48.0% of GS surgeons reported using IONM, and 44.3% of OTO-HNS and 30.8% of GS respondents used IONM in all thyroid cases. For thyroid surgery, as surgical volume increased, surgeons were more likely to use IONM more frequently. Fourteen percent of the OTO-HNS and 41.7% of the GS respondents used IONM primarily to locate the RLN. Forty percent of the OTO- HNS and 8.3% of the GS used IONM for medicolegal reasons. The majority of OTO-HNS programs use IONM for thyroid and parathyroid surgery, whereas less than half of GS programs regularly use IONM for these surgeries. Thyroid surgeons, with larger thyroid surgery volume, regardless of discipline, tend to use IONM 290

7 more. The motivations for using IONM differ significantly between OTO-HNS and general surgeons in that more GS use it for locating the RLN, and more OTO- HNS use it for continuous monitoring of the nerve during resection and for medicolegal purposes. 16 Dionigi et al. recently published outcomes of a point prevalence survey on utilization, management, and documentation of intraoperative neuromonitoring in thyroid surgery in Italy. 17 Source data were mixed from Italian surgeons attending the Annual Meeting of the INMSG in 2014, four IONM manufacturers available in Italy, and surgical units identified from company sales data. Questions were regarding IONM prevalence, surgical background, hospital geographic practice location, type of hospital, rationale for IONM use, sources of initial capital investment for IONM acquisition, type of equipment, use of continuous IONM, monitoring management, use of distinctive standards, and IONM documentation. As shown by outcomes of that survey, IONM was currently delivered through 48 units in Italy. In 2013, the distribution of IONM by specialties included general (50%); ear, nose, and throat (46%); and thoracic surgery (4%). Overall, 12,853 IONM procedures were performed between 2006 and 2013: 253 were performed in 2007 and about 5,100 in Distribution according to the type of hospital was public 48%, academic setting 37%, and private maintenance 15%. The use category of high-volume thyroid hospitals represented 33%. Overall motivations expressed are legal (30%), RLN confirmation (20%), RLN identification (20%), prognosis (10%), helpful in difficult cases (10%), decrease surgical time (5%), and educational (5%). The survey revealed that participants had limited experience with the standardized approach for IONM (28%). General IONM information to patients and/or subsequent specific IONM informed consent was initiated in 8% of centers. 17 This study has also several limitations. It provides limited survey pilot data exploring the utilization of the RLN, EBSLN monitoring, and laryngeal examination of thyroidectomy in a highly selected subset of thyroid surgeons. Prospective multicenter studies are needed to guide an evidence-based management of the IONM and laryngeal examination during thyroidectomy. Our study group represents a group of surgeons attending endocrine surgical educational programming and so are highly selected. The group, which is characterized by a third having over 200 cases a year and therefore represents a highly experienced subset, may not represent the opinions held in the general surgical community. Our group is also over-represented by general surgeons as opposed to otolaryngologists and is predominantly European. Also, our group is over-represented by academic physicians as opposed to private practice. However, because our study population is drawn from surgical courses, it avoids potential organizational biases that may affect other similar survey papers in the field. Additionally, our group represents a large number of respondents over wide geographic areas and is characterized by a range of surgical experience and training backgrounds. CONCLUSION Many aspects of RLN, EBSLN monitoring, and laryngeal examination during thyroidectomy differ between surgeons of varying volume, age, and training background. Utilization of IONM to identify the nerve and test its function intraoperatively is dependent on individual surgical preferences. High-volume surgeons, those with an otolaryngology background, and those at a younger age are more aware of the potential benefits of IONM technique for better voice preservation. Routine use of monitoring for the EBSLN is less common than for the RLN. Use of IONM and laryngeal examination appears to be linked. IONM data are used by many to stage thyroid surgery in benign rather than malignant disease. Use of laryngeal examination is also more common in higher-volume surgeons. Prospective multicenter studies are needed to guide evidence-based management of the EBSL during thyroidectomy. BIBLIOGRAPHY 1. Randolph GW, Dralle H, et al.; International Intraoperative Monitoring Study Group. Electrophysiologic recurrent laryngeal nerve monitoring during thyroid and parathyroid surgery: international standards guideline statement. Laryngoscope 2011;121(suppl 1):S1 S Cernea CR, Ferraz AR, Furlani J, et al. Identification of the external branch of the superior laryngeal nerve during thyroidectomy. Am J Surg 1992;164: Lore JM Jr, Kokocharov SI, Kaufman S, Richmond A, Sundquist N. Thirty-eight-year evaluation of a surgical technique to protect the external branch of the superior laryngeal nerve during thyroidectomy. Ann Otol Rhinol Laryngol 1998;107: Bellantone R, Boscherini M, Lombardi CP, et al. Is the identification of the external branch of the superior laryngeal nerve mandatory in thyroid operation? Results of a prospective randomized study. Surgery 2001;130: Aina EN, Hisham AN. External laryngeal nerve in thyroid surgery: recognition and surgical implications. ANZ J Surg 2001;71: Jonas J, Bahr R. Neuromonitoring of the external branch of the superior laryngeal nerve during thyroid surgery. Am J Surg 2000;179: Barczynski M, Konturek A, Stopa M, Honowska A, wak W. Randomized controlled trial of visualization versus neuromonitoring of the external branch of the superior laryngeal nerve during thyroidectomy. World J Surg 2012;36: Masuoka H, Miyauchi A, Higashiyama T, et al. Prospective randomized study on injury of the external branch of the superior laryngeal nerve during thyroidectomy comparing intraoperative nerve monitoring and a conventional technique [published online May 21, 2014]. Head Neck. doi: /hed Randolph GW. SLN monitoring. In: Randolph GW, ed. Surgery of the Thyroid and Parathyroid Glands. 2nd ed. Philadelphia, PA: Elsevier/Saunders; 2012: Barczynski M, Randolph GW, Cernea CR, et al. External branch of the superior laryngeal nerve monitoring during thyroid and parathyroid surgery: International Neural Monitoring Study Group standards guideline statement. Laryngoscope 2013;123(suppl 4):S1 S Randolph GW, Kamani D. Intraoperative neural monitoring in thyroid cancer surgery. Langenbecks Arch Surg 2014;399: Potenza AS, Phelan EA, Cernea CR, et al. rmative intra-operative electrophysiologic waveform analysis of superior laryngeal nerve external branch and recurrent laryngeal nerve in patients undergoing thyroid surgery. World J Surg 2013;37: Darr EA, Tufano RP, Ozdemir S, Kamani D, Hurwitz S, Randolph G. Superior laryngeal nerve quantitative intraoperative monitoring is possible in all thyroid surgeries. Laryngoscope 2014;124: Sritharan N, Chase M, Kamani D, Randolph M, Randolph GW. 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