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Chen H, Xu K, Peng X, Min X. Key points for protecting the external branch of the superior laryngeal nerve in open thyroidectomy: A possible exploration technique. Surg Oncol 2024; 53:102059. [PMID: 38461616 DOI: 10.1016/j.suronc.2024.102059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 01/29/2024] [Accepted: 02/28/2024] [Indexed: 03/12/2024]
Abstract
OBJECTIVE Injury of the external branch of the superior laryngeal nerve (EBSLN) is easily overlooked in thyroidectomy, and voice changes caused by the injury have a negative effect on an increasing number of patients. This study aimed to reduce the injury rate of EBSLN by expanding the sternothyroid-laryngeal triangle and standardizing the exploration procedure. METHODS A total of 520 patients who had undergone thyroidectomy at the First Affiliated Hospital of Nanchang University between September 2021 and April 2022 were analyzed. During the operation, the exposure rate of the EBSLN before and after sternothyroid-laryngeal triangle expansion was compared, and all EBSLNs were anatomically classified. RESULTS The exposure rate of EBSLN after sternothyroid-laryngeal triangle expansion reached 82.7%, which is much higher than that before sternothyroid-laryngeal triangle expansion (33.7%), and voice change caused by injury of the EBSLN was reported in one case (the injury rate was 0.2%). The classification and proportion of the EBSLN were as follows: Type 1 (55.3%), the nerve ran within 1 cm above the STP, but no coincidence or crossover with blood vessels was observed in this region; Type 2 (14.7%), the nerve travelled within 1 cm above the STP and overlapped or intersected with blood vessels in this region; Type 3 (12.7%), the EBSLN ran below the level of the STP; and Type 4 (17.3%), no EBSLN was observed within 1 cm above the STP. CONCLUSION In thyroidectomy, injury to the EBSLN can be effectively reduced by expanding the sternothyroid-laryngeal triangle and exploring the upper pole area of the thyroid as far as possible, which has great clinical significance in reducing postoperative voice box injury.
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Affiliation(s)
- Hang Chen
- Department of Day Ward, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, China
| | - Keyi Xu
- Department of Day Ward, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, China
| | - Xueying Peng
- Department of Day Ward, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, China
| | - Xiang Min
- Department of Day Ward, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, China.
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Aygun N, Unlu MT, Kostek M, Caliskan O, Isgor A, Uludag M. Intraoperative cricothyroid muscle electromyography may contribute to the monitorization of the external branch of the superior laryngeal nerve during thyroidectomy. Front Endocrinol (Lausanne) 2023; 14:1303159. [PMID: 38130395 PMCID: PMC10733446 DOI: 10.3389/fendo.2023.1303159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
Background In thyroid surgery, both the recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN) should be preserved for maintaining the vocal cord functions. We aimed to evaluate whether EMG of the CTM applied after the superior pole dissection provided additional informative data to the IONM via ETT or not, regarding the EBSLN function. Methods The prospectively collected data of the patients, who have undergone thyroidectomy with the use of IONM for the exploration of both the RLN and EBSLN between October 2016 and March 2017, were evaluated retrospectively. Patients over 18 years of age with primary thyroid surgery for malignant or benign thyroid disease, and whom were applied CTM EMG with a needle electrode after the completion of thyroidectomy were included in the study. In the study, each neck side was evaluated as a separate entity considering the EBSLN at risk. Results The data of 41 patients (32 female, 9 male) (mean age, 46.7 + 9.1; range, 22-71) were evaluated. Sixty seven EBSLNs out of 26 bilateral and 15 unilateral interventions were evaluated. With EBSLN stimulation after the superior pole dissection, positive glottic EMG waveforms via ETT were obtained in 45 (67.2%) out of 67, and the mean glottic amplitude value was 261 + 191 μV (min-max: 116-1086 μV). Positive EMG responses via the CTM EMG were achieved from all of the 67 EBSLNs (100%) with stimulation using a monopolar probe at the most cranial portion above the area of divided superior pole vessels. The mean value of CTM amplitudes via CTM EMG obtained with EBSLN stimulation was 5268 + 3916 μV (min-max:1215 -19726 μV). With EBSLN stimulation, the mean CTM EMG amplitude was detected significantly higher than the mean vocal cord amplitude (p<0.0001). The CTM EMG provided more objective quantifiable data regarding the EBSLN function (100% vs 67,2%, p<0.001). Conclusion In addition to the IONM via ETT, intraoperative post-dissection CTM EMG via needle electrode is a safe, simple and applicable method that may provide significant additional informative data to IONM with ETT by obtaining and recording objective quantitative data related to the EBSLN function.
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Affiliation(s)
- Nurcihan Aygun
- General Surgery Department, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
| | - Mehmet Taner Unlu
- General Surgery Department, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
| | - Mehmet Kostek
- General Surgery Department, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
| | - Ozan Caliskan
- General Surgery Department, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
| | - Adnan Isgor
- General Surgery Department, Memorial Sisli Hospital, Sisli, Istanbul, Türkiye
| | - Mehmet Uludag
- General Surgery Department, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Türkiye
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Li C, Zhang J, Dionigi G, Sun H. Assessment of different classification systems for predicting the risk of superior laryngeal nerve injury during thyroid surgery: a prospective cohort study. Front Endocrinol (Lausanne) 2023; 14:1301838. [PMID: 38075061 PMCID: PMC10703432 DOI: 10.3389/fendo.2023.1301838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 10/30/2023] [Indexed: 12/18/2023] Open
Abstract
Background A multitude of anatomical variations have been noted in the external branch of the superior laryngeal nerve (EBSLN). In this study, intraoperative neuromonitoring (IONM) was used to assess the potential value of the different classical EBSLN classifications for predicting the risk of EBSLN injury. Methods In total, 136 patients with thyroid nodules were included in this prospective cohort study, covering 242 nerves at risk (NAR). The EBSLN was identified by observing the cricothyroid muscle twitch and/or typical electromyography (EMG) biphasic waveform. The EBSLNs were classified by Cernea classification, Kierner classification, and Friedman classification, respectively. The EMG parameters and outcomes of vocal acoustic assessment were recorded. Results The distribution of Cernea, Kiernea, and Friedman subtypes were, respectively, Cernea 1 (40.9%), Cernea 2A (45.5%), Cernea 2B (10.7%), Kierner 1 (40.9%), Kierner 2 (45.5%), Kierner 3 (10.7%), Kierner 4 (2.9%) and Friedman 1 (15.7%), Friedman 2 (33.9%), Friedman 3 (50.4%). The amplitudes of EBSLN decreased significantly after superior thyroid pole operation, respectively, in Cernea 2A (193.7 vs. 226.6μV, P=0.019), Cernea 2B (185.8 vs. 221.3μV, P=0.039), Kierner 2 (193.7vs. 226.6μV, P=0.019), Kierner 3 (185.8 vs. 221.3μV, P=0.039), Kierner 4 (126.8vs. 226.0μV, P=0.015) and Friedman type 2 (184.8 vs. 221.6μV, P=0.030). There were significant differences in Fmax and Frange for Cernea 2A (P=0.001, P=0.001), 2B (P=0.001, P=0.038), Kierner 2 (P=0.001), Kierner 3 (P=0.001, P=0.038), and Friedman 2 (P=0.004, P=0.014). In the predictive efficacy of EBSLN injury, the Friedman classification showed higher accuracy (69.8% vs. 44.3% vs. 45.0%), sensitivity (19.5% vs. 11.0% vs. 14.0%), and specificity (95.6% vs. 89.9% vs. 89.9%) than the Cernea and Kierner classifications. However, the false negative rate of Friedman classification was significantly higher than other subtypes (19.5% vs. 11.0% vs. 14.0%). Conclusion Cernea 2A and 2B; Kierner 2, 3, and 4; and Friedman 2 were defined as the high-risk subtypes of EBSLN. The risk prediction ability of the Friedman classification was found to be superior compared to other classifications.
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Affiliation(s)
- Changlin Li
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Engineering Laboratory of Thyroid Disease Prevention and Control, Changchun, Jilin, China
| | - Jiao Zhang
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Engineering Laboratory of Thyroid Disease Prevention and Control, Changchun, Jilin, China
| | - Gianlorenzo Dionigi
- Division of Surgery, Istituto Auxologico Italiano Istituto di Ricovero e Cura a Carattere Scientifco (IRCCS), Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Hui Sun
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Engineering Laboratory of Thyroid Disease Prevention and Control, Changchun, Jilin, China
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Zhao Y, Zhao Z, Zhang D, Han Y, Dionigi G, Sun H. Improving classification of the external branch of the superior laryngeal nerve with neural monitoring: a research appraisal and narrative review. Gland Surg 2021; 10:2847-2860. [PMID: 34733732 DOI: 10.21037/gs-21-518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/16/2021] [Indexed: 11/06/2022]
Abstract
Objective To review the published literature on external branch of superior laryngeal nerve (EBSLN) neural monitoring and propose a new EBSLN classification system using intraoperative neural monitoring (IONM). Background The injury rate of the external branch of the superior laryngeal nerve (EBSLN) in thyroid surgery is 0-58%. Symptoms of EBSLN injury are not consistent, and patients often complain of modification of the voice timbre with the preservation of vocal cord function. Standards for the diagnosis of EBSLN injury are lacking. Methods The PubMed database was searched using the terms 'External branch of the superior laryngeal nerve' and 'Intraoperative neuromonitoring' from 2010 through March 2020. Conclusions This paper reviewed the anatomy of the EBSLN, the diagnosis and treatment of injury, and the application of IONM in the EBSLN. The traditional EBSLN classification method was analyzed and compared with our new classification method. The diagnosis of EBSLN injury is a problem that still needs to be resolved. For anatomic classifications of the EBSLN, we found that the conventional classification systems may not accurately reflect the real status of the EBSLN and the surgical risks that may occur intraoperatively. Using IONM, we developed an EBSLN classification method that was consistent with conventional diagnosis and treatments and can be widely and easily utilized during surgery.
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Affiliation(s)
- Yishen Zhao
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
| | - Zihan Zhao
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
| | - Daqi Zhang
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
| | - Yujia Han
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
| | - Gianlorenzo Dionigi
- Division of General Surgery, Head, Endocrine Surgery Section, Istituto Auxologico Italiano IRCCS, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Hui Sun
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
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Bawa D, Alghamdi A, Albishi H, Al-Tufail N, Sharma SP, Khalifa YM, Khan S, Alhajmohammed MA. Post-thyroidectomy complications in southwestern Saudi Arabia: a retrospective study of a 6-year period. Ann Saudi Med 2021; 41:369-375. [PMID: 34873936 PMCID: PMC8650599 DOI: 10.5144/0256-4947.2021.369] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Thyroidectomy is the surgical removal of all or part of the thyroid gland for non-neoplastic and neoplastic thyroid diseases. Major postoperative complications of thyroidectomy, including recurrent laryngeal nerve injury, hypocalcemia, and hypothyroidism, are not infrequent. OBJECTIVE Summarize the frequency of surgical complications of thyroidectomy. DESIGN Retrospective. SETTING Secondary health facility in southwestern Saudi Arabia. PATIENTS AND METHODS We collected data from the records of patients who were managed for thyroid diseases between December 2013 and December 2019. MAIN OUTCOME MEASURE Complications following thyroidectomy. SAMPLE SIZE 339 patients, 280 (82.6%) females and 59 (17.4%) males. RESULTS We found 311 (91.7%) benign and 28 (8.3%) malignant thyroid disorders. Definitive management included 129 (38.1%) total thyroidectomies, 70 (20.6%) hemithyroidectomies, 10 (2.9%) subtotal thyroidectomies and 5 (1.5%) near-total thyroidectomies with 125 (36.9%) patients treated non-surgically. The overall complication rate was 11.3%. There were 4 (1.9%) patients with recurrent laryngeal nerve palsy, 16 (7.5%) patients with temporary hypoparathyroidism, 1 (0.5%) patient with paralysis of the external branch of the superior laryngeal nerve and 3 (1.4%) patients with wound hematoma. CONCLUSION The rate of complications following thyroidectomy is still high. There is a need for emphasis on comprehensive measures to control the high rate of complications. LIMITATIONS Retrospective design and no long-term follow up to monitor late complications. CONFLICT OF INTEREST None.
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Affiliation(s)
- Dauda Bawa
- From the Department of Surgery, King Abdullah Hospital, Bisha, Asir, Saudi Arabia
| | - Amal Alghamdi
- From the Department of Surgery, King Abdullah Hospital, Bisha, Asir, Saudi Arabia
| | - Hanan Albishi
- From the Department of Surgery, King Abdullah Hospital, Bisha, Asir, Saudi Arabia
| | - Nasser Al-Tufail
- From the Department of Surgery, King Abdullah Hospital, Bisha, Asir, Saudi Arabia
| | - Shashi Prabha Sharma
- From the Department of Pathology, King Abdullah Hospital, Bisha, Asir, Saudi Arabia
| | | | - Saleem Khan
- From the Department of Surgery, King Abdullah Hospital, Bisha, Asir, Saudi Arabia
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Choi HW, Ji YB, Kim E, Kim KN, Tae K. Success rate and learning curve of intraoperative neural monitoring of the external branch of the superior laryngeal nerve in thyroidectomy. Head Neck 2021; 43:3946-3954. [PMID: 34632669 DOI: 10.1002/hed.26895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 09/14/2021] [Accepted: 09/21/2021] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND This study aimed to evaluate the success rate and learning curve of intraoperative neural monitoring (IONM) of the external branch of the superior laryngeal nerve (EBSLN) in thyroidectomy. METHODS We studied 130 consecutive patients (200 nerves at risk [NARs]) who had undergone conventional thyroidectomy with IONM of the recurrent laryngeal nerve (RLN) and EBSLN from January 2017 to March 2020. The learning curve was defined as the number of NARs required to achieve an effective and reliable neuromonitoring rate. RESULTS IONM of the EBSLN was successful in 136/200 (68%) NARs. The cutoff point of the learning curve was 45 NARs (28 patients). The neural identification rate of EBSLN was significantly higher in the post-learning 155 NARs group than the pre-learning group (82.6% vs. 17.8%, p < 0.001). CONCLUSIONS Approximately 45 NAR neuromonitoring attempts were required to reach a significant increase in the EBSLN identification rate and overcome the learning curve.
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Affiliation(s)
- Hae Won Choi
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Hanyang University, Seoul, Republic of Korea
| | - Yong Bae Ji
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Hanyang University, Seoul, Republic of Korea
| | - Eugene Kim
- Department of Anesthesiology and Pain Medicine, College of Medicine, Hanyang University, Seoul, Republic of Korea
| | - Kyu Nam Kim
- Department of Anesthesiology and Pain Medicine, College of Medicine, Hanyang University, Seoul, Republic of Korea
| | - Kyung Tae
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Hanyang University, Seoul, Republic of Korea
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Anatomical, Functional, and Dynamic Evidences Obtained by Intraoperative Neuromonitoring Improving the Standards of Thyroidectomy. MEDICAL BULLETIN OF SISLI ETFAL HOSPITAL 2021; 55:146-155. [PMID: 34349588 PMCID: PMC8298074 DOI: 10.14744/semb.2021.45548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 06/07/2021] [Indexed: 12/19/2022]
Abstract
The use of intraoperative neuromonitoring (IONM) is getting more common in thyroidectomy. The data obtained by the usage of IONM regarding the laryngeal nerves’ anatomy and function have provided important contributions for improving the standards of the thyroidectomy. These evidences obtained through IONM increase the rate of detection and visual identification of recurrent laryngeal nerve (RLN) as well as the detection rate of extralaryngeal branches which are the most common anatomic variations of RLN. IONM helps early identification and preservation of the non-recurrent laryngeal nerve. Crucial knowledge has been acquired regarding the complex innervation pattern of the larynx. Extralaryngeal branches of the RLN may contribute to the motor innervation of the cricothyroid muscle (CTM). Anterior branch of the extralaryngeal branching RLN has always motor function and gives motor branches both to the abductor and adductor muscles. In addition, up to 18% of posterior branches may have adductor and/or abductor motor fibers. In 70–80% of cases, external branch of superior laryngeal nerve (EBSLN) provides motor innervation to the anterior 1/3 of the thyroarytenoid muscle which is the main adductor of the vocal cord through the human communicating nerve. Furthermore, approximately 1/3 of the cases, EBSLN may contribute to the innervation of posterior cricoarytenoid muscle which is the main abductor of ipsilateral vocal cord. RLN and/or EBSLN together with pharyngeal plexus usually contribute to the motor innervation of cricopharyngeal muscle that is the main component of upper esophageal sphincter. Traction trauma is the most common reason of RLN injuries and constitutes of 67–93% of cases. More than 50% of EBSLN injuries are caused by nerve transection. A specific point of injury on RLN can be detected in Type 1 (segmental) injury, however, Type 2 (global) injury is the loss of signal (LOS) throughout ipsilateral vagus-RLN axis and there is no electrophysiologically detectable point of injury. Vocal cord paralysis (VCP) develops in 70–80% of cases when LOS persists or incomplete recovery of signal occurs after waiting for 20 min. In case of complete recovery of signal, VCP is not expected. VCP is temporary in patients with incomplete recovery of signal and permanent VCP is not anticipated. Visual changes may be seen in only 15% of RLN injuries, on the other hand, IONM detects 100% of RLN injuries. IONM can prevent bilateral VCP. Continuous IONM (C-IONM) is a method in which functional integrity of vagus-RLN axis is evaluated in real time and C-IONM is superior to intermittent IONM (I-IONM). During upper pole dissection, IONM makes significant contributions to the visual and functional identification of EBSLN. Routine use of IONM may minimalize the risk of nerve injury. Reduction of amplitude more than 50% on CTM is related with poor voice outcome.
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Can we routinely identify the external branch of the superior laryngeal nerves with neural monitoring?: a prospective report on 176 consecutive nerves at risk. Updates Surg 2021; 73:2275-2281. [PMID: 34041716 PMCID: PMC8606392 DOI: 10.1007/s13304-021-01084-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/05/2021] [Indexed: 01/15/2023]
Abstract
The external branch of the superior laryngeal nerve (EBSLN) provides motor function to the cricothyroid muscle (CTM). EBSLN damage produces changes in voice quality and projection. Intraoperative neuromonitoring (IONM) in thyroid surgery aims to optimize EBSLN control during dissection. We prospectively collected the data of 88 consecutive patients who underwent total thyroidectomy with IONM from July 2019 to December 2019. IONM was offered in the intermittent mode of application. We routinely searched for the EBSLN electromyographic (EMG) signal before (S1) and after (S2) dissection of the superior vascular peduncle. In the absence of the EMG signal, we observed the CTM twitch. We identified 141 (80%) S1 EMG signals, while we recorded the CTM twitch in 15 cases (8.5%). In 20 (11.3%) cases, we were unable to identify the EMG signal. Analysing the S2 results, we found loss of EBSLN signal in 11/141 cases (7.8%) identified with IONM in pre-dissection stimulation. Among the 20 cases without pre-dissection identification (we had not identified the external branch of the superior laryngeal nerve or the muscle twitch), in the post-dissection evaluation, we confirmed the loss of signal in 17 of 20 cases, equal to 85% (p < 0.001). Our data clearly show that intraoperative stimulation and recognition of EBSLN, performed before any dissection manoeuvre to the superior vascular thyroid pole, leads to a much higher rate of nerve conservation.
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Devaraja K, Punja R, Kalthur SG, Pujary K. Unmapped landmarks around branches of the Superior Laryngeal Nerve: An exploratory cadaveric study. J Taibah Univ Med Sci 2021; 16:328-335. [PMID: 34140858 PMCID: PMC8178688 DOI: 10.1016/j.jtumed.2021.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/30/2020] [Accepted: 01/07/2021] [Indexed: 11/05/2022] Open
Abstract
Objectives Preserving the External Branch of Superior Laryngeal Nerve (EBSLN) and Internal Branch of Superior Laryngeal Nerve (IBSLN) is essential during thyroidectomy. However, due to potential distortions caused by large goitres, the present anatomical landmarks used to identify these nerves are flawed. Although under such circumstances, bony landmarks may offer more stable reference points, not much has been explored in this regard. This study measures the distance between the most vulnerable points of the EBSLN and IBSLN and their relatively unexplored bony landmarks, such as the hyoid bone and thyroid notch as well as soft-tissue landmarks like the origin of the Superior Thyroid Artery (STA) and carotid bifurcation. Methods An exploratory cadaveric study was conducted in a medical school affiliated with a tertiary care hospital. The detailed analysis included 13 sides from 8 cadavers. Results The average distance from the EBSLN piercing site to the greater cornua of the hyoid bone, thyroid cartilage prominence, origin of the STA, and carotid bifurcation was 35.1(±7.2) mm, 33.3(±3.8) mm, 25.7(±6.3) mm, and 31.5(±5.0) mm, respectively and from the IBSLN piercing site was 15.9(±5.9) mm, 32.9(±4.7) mm, 16.3(±4.2) mm, and 20.7(±5.9) mm, respectively. For most cadavers, the distal EBSLN had Cernea type 2a-like relationship with the STA. Certain variations were also observed in the way these nerves branched with respect to the origin of the STA. Conclusions This study provides metric information (linear measurements) regarding the distance between the branches of SLN and certain unique landmarks. This could potentially aid in minimising intraoperative trauma to these branches.
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Affiliation(s)
- K Devaraja
- Department of Otorhinolaryngology and Head and Neck Surgery, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Rohini Punja
- Department of Anatomy, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Sneha G Kalthur
- Department of Anatomy, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Kailesh Pujary
- Department of Otorhinolaryngology and Head and Neck Surgery, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
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Iwata AJ, Liddy W, Barczyński M, Wu CW, Huang TY, Van Slycke S, Schneider R, Dionigi G, Dralle H, Cernea CR, Kamani D, Ahmed AH, Okose OC, Wang B, Randolph GW. Superior Laryngeal Nerve Signal Attenuation Influences Voice Outcomes in Thyroid Surgery. Laryngoscope 2021; 131:1436-1442. [PMID: 33521945 DOI: 10.1002/lary.29413] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/06/2021] [Accepted: 01/10/2021] [Indexed: 01/07/2023]
Abstract
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.
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Affiliation(s)
- Ayaka J Iwata
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A
| | - Whitney Liddy
- Department of Otolaryngology - Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Marcin Barczyński
- Department of Endocrine Surgery, Third Chair of General Surgery, Jagiellonian University Medical College, Krakow, Poland
| | - Che-Wei Wu
- Department of Otolaryngology - Head and Neck Surgery, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Tzu-Yen Huang
- Department of Otolaryngology - Head and Neck Surgery, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Sam Van Slycke
- Department of General and Endocrine Surgery, Onze-Lieve-Vrouw (OLV) Ziekenhuis Aalst, Aalst, Belgium
| | - Rick Schneider
- Department of Surgery, University Hospital Halle, Martin-Luther-University, Haller-Wittenberg, Germany
| | - Gianlorenzo Dionigi
- Division for Endocrine and Minimally Invasive Surgery. Department of Human Pathology in Adulthood and Childhood "G. Barresi", University Hospital G. Martino, University of Messina, Messina, Italy
| | - Henning Dralle
- Department of General, Visceral and Transplantation Surgery, University of Duisburg-Essen, Essen, Germany
| | - Claudio R Cernea
- Department of Surgery, Head and Neck Surgery Service of the Hospital das Clínicas, University of Sao Paulo, Sao Paulo, Brazil
| | - Dipti Kamani
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A
| | - Amr H Ahmed
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A
| | - Okenwa C Okose
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A
| | - Bo Wang
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A.,Department of Thyroid Surgery, Fujian Medical University Union Hospital, Fujian, China
| | - Gregory W Randolph
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A.,Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, U.S.A
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11
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Zhao Y, Zhao Z, Wang T, Zhang D, Dionigi G, Sun H. The area under the waveform of electromyography for monitoring the external branches of the superior laryngeal nerve during thyroid surgery. Gland Surg 2021; 10:143-153. [PMID: 33633971 DOI: 10.21037/gs-20-570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Background Injuries to the external branches of the superior laryngeal nerve (EBSLN) are difficult to identify during thyroidectomy. Monitoring the low amplitudes of the EBSLN during surgery has proven to be complicated. Therefore a new parameter, the area under the waveform (AUW), was designed to improve monitoring efficiency. The aim of this study was to determine the effectiveness of using AUW to monitor the EBSLN during thyroidectomy. Methods A total of 927 patients and 927 recurrent laryngeal nerves (RLN) and EBSLNs who underwent monitored unilateral thyroidectomy were included. Standardized intraoperative neuromonitoring procedures were followed. RLN injuries were confirmed using stroboscopic laryngoscopy after surgery. EBSLN injuries were identified by means of observing changes in cricothyroid muscle (CTM) twitches when stimulated. Amplitude and AUW changes were assessed using statistical analysis. The correlations between AUW and amplitude were verified using the ratio of the two parameters to determine any decreases that were observed in the number of nerve injury cases. The receiver operating characteristic (ROC) curve was used to estimate the prediction of nerve injury. Results The overall injury rates of the RLN and EBSLN were 3.56% and 2.05%, respectively. The AUW for the RLN and EBSLN presented linear correlations with amplitude. In the RLN injury cases, no significant difference was observed between the two parameters (P>0.05). In the cases with EBSLN injuries, the AUW decreased 64.5%±14.1%, on average, which was a greater decrease compared to that observed for amplitude 49.7%±22.2% (P<0.0001). The summary of the EBSLN injury prediction included, amplitude vs. AUW, AUC: 0.918 vs. 0.994; P<0.0001, and Youden's index: 31.54% vs. 49.58%. Conclusions The AUW demonstrated consistency with the change in amplitude, and the observed changes were significant. The use of the AUW allowed successful predictions for both RLN and EBSLN nerve injuries. Also, the sensitivity of AUW was greater than amplitude for predicting EBSLN injuries.
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Affiliation(s)
- Yishen Zhao
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
| | - Zihan Zhao
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
| | - Tie Wang
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
| | - Daqi Zhang
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
| | - Gianlorenzo Dionigi
- Division for Endocrine and Minimally Invasive Surgery, Department of Human Pathology in Adulthood and Childhood 'Gaetano Barresi', University Hospital G. Martino, University of Messina, Messina, Italy
| | - Hui Sun
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine on Differentiated Thyroid Carcinoma, Changchun, China
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12
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Wu CW, Randolph GW, Barczyński M, Schneider R, Chiang FY, Huang TY, Karcioglu AS, Konturek A, Frattini F, Weber F, Liu CH, Dralle H, Dionigi G. Training Courses in Laryngeal Nerve Monitoring in Thyroid and Parathyroid Surgery- The INMSG Consensus Statement. Front Endocrinol (Lausanne) 2021; 12:705346. [PMID: 34220726 PMCID: PMC8253252 DOI: 10.3389/fendo.2021.705346] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/26/2021] [Indexed: 01/04/2023] Open
Abstract
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.
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Affiliation(s)
- Che-Wei Wu
- International Thyroid Surgery Center, Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Center for Liquid Biopsy and Cohort Research, and Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Gregory W. Randolph
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, United States
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Marcin Barczyński
- Department of Endocrine Surgery, Third Chair of General Surgery, Jagiellonian University Medical College, Krakow, Poland
| | - Rick Schneider
- Department of Surgery, University Hospital Halle, Martin-Luther-University, Halle-Wittenberg, Germany
| | - Feng-Yu Chiang
- Department of Otolaryngology, E-Da Hospital, School of Medicine, College of Medicine, I-Shou University, Kaohsiung, Taiwan
| | - Tzu-Yen Huang
- International Thyroid Surgery Center, Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Center for Liquid Biopsy and Cohort Research, and Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Amanda Silver Karcioglu
- Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, NorthShore University HealthSystem, Evanston, IL, United States
| | - Aleksander Konturek
- Department of Endocrine Surgery, Third Chair of General Surgery, Jagiellonian University Medical College, Krakow, Poland
| | - Francesco Frattini
- Department of Surgery, Ospedale di Circolo, ASST Settelaghi, Varese, Italy
| | - Frank Weber
- Department of General, Visceral and Transplantation Surgery, University of Duisburg-Essen, Essen, Germany
| | - Cheng-Hsin Liu
- International Thyroid Surgery Center, Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Henning Dralle
- Department of General, Visceral and Transplantation Surgery, University of Duisburg-Essen, Essen, Germany
| | - Gianlorenzo Dionigi
- Department of Human Pathology in Adulthood and Childhood “G. Barresi”, University Hospital G. Martino, University of Messina, Messina, Italy
- *Correspondence: Gianlorenzo Dionigi,
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13
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Wu CW, Huang TY, Randolph GW, Barczyński M, Schneider R, Chiang FY, Silver Karcioglu A, Wojtczak B, Frattini F, Gualniera P, Sun H, Weber F, Angelos P, Dralle H, Dionigi G. Informed Consent for Intraoperative Neural Monitoring in Thyroid and Parathyroid Surgery - Consensus Statement of the International Neural Monitoring Study Group. Front Endocrinol (Lausanne) 2021; 12:795281. [PMID: 34950109 PMCID: PMC8689131 DOI: 10.3389/fendo.2021.795281] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/08/2021] [Indexed: 11/13/2022] Open
Abstract
In the past decade, the use of intraoperative neural monitoring (IONM) in thyroid and parathyroid surgery has been widely accepted by surgeons as a useful technology for improving laryngeal nerve identification and voice outcomes, facilitating neurophysiological research, educating and training surgeons, and reducing surgical complications and malpractice litigation. Informing patients about IONM is not only good practice and helpful in promoting the efficient use of IONM resources but is indispensable for effective shared decision making between the patient and surgeon. The International Neural Monitoring Study Group (INMSG) feels complete discussion of IONM in the preoperative planning and patient consent process is important in all patients undergoing thyroid and parathyroid surgery. The purpose of this publication is to evaluate the impact of IONM on the informed consent process before thyroid and parathyroid surgery and to review the current INMSG consensus on evidence-based consent. The objective of this consensus statement, which outlines general and specific considerations as well as recommended criteria for informed consent for the use of IONM, is to assist surgeons and patients in the processes of informed consent and shared decision making before thyroid and parathyroid surgery.
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Affiliation(s)
- Che-Wei Wu
- Department of Otorhinolaryngology-Head and Neck Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Center for Liquid Biopsy and Cohort Research, and Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Tzu-Yen Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Gregory W. Randolph
- Department of Otolaryngology, Harvard Medical School, Boston, MA, United States
| | - Marcin Barczyński
- Department of Endocrine Surgery, Third Chair of General Surgery, Jagiellonian University Medical College, Krakow, Poland
| | - Rick Schneider
- Department of Visceral, Vascular and Endocrine Surgery, University Hospital Halle, Martin-Luther-University, Halle-Wittenberg, Germany
| | - Feng-Yu Chiang
- Department of Otolaryngology, E-Da Hospital, School of Medicine, College of Medicine, I-Shou University, Kaohsiung, Taiwan
| | | | - Beata Wojtczak
- Department of General, Minimally Invasive and Endocrine Surgery, Wroclaw Medical University, Wroclaw, Poland
| | - Francesco Frattini
- Department of Surgery, Ospedale di Circolo, ASST, Settelaghi, Varese, Italy
| | - Patrizia Gualniera
- Forensics Division, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, Italy
| | - Hui Sun
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Frank Weber
- Department of General, Visceral and Transplantation Surgery, University of Duisburg-Essen, Essen, Germany
| | - Peter Angelos
- Department of Surgery and MacLean Center for Clinical Medical Ethics, The University of Chicago, Chicago, IL, United States
| | - Henning Dralle
- Department of General, Visceral and Transplantation Surgery, University of Duisburg-Essen, Essen, Germany
| | - Gianlorenzo Dionigi
- Division of Surgery, Istituto Auxologico Italiano IRCCS, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
- *Correspondence: Gianlorenzo Dionigi,
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14
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Heikkinen M, Penttilä E, Qvarnström M, Mäkinen K, Löppönen H, Kärkkäinen JM. Perceptual Assessment and Acoustic Voice Analysis as Screening Tests for Vocal Fold Paresis After Thyroid or Parathyroid Surgery. World J Surg 2020; 45:765-773. [PMID: 33249535 PMCID: PMC7851023 DOI: 10.1007/s00268-020-05863-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2020] [Indexed: 11/25/2022]
Abstract
Background The aim of this study was to evaluate the reliability of clinician-based perceptual assessment of voice and computerized acoustic voice analysis as screening tests for vocal fold paresis or paralysis (VFP) after thyroid and parathyroid surgery. Methods This was a prospective study of 181 patients undergoing thyroid or parathyroid procedure with pre and postoperative laryngoscopic vocal fold inspection, perceptual voice assessment using grade, roughness, breathiness, asthenia, and strain (GRBAS) scale and acoustic voice analysis using the multi-dimensional voice program (MDVP). Patients were divided into 2 groups for comparison; those with new postoperative VFP and those without. Potential screening tools were evaluated using the receiving operating characteristic (ROC) analysis. Results Fourteen (6.6%) patients had a new postoperative VFP. Postoperative GRBAS scores were significantly (P < 0.05) higher in patients with VFP compared to those without. However, there were no statistically significant differences in MDVP values between the groups. Postoperative GRBAS grade score (cut off > 0) had the best sensitivity, 93%, for predicting VFP, but the specificity was only 50%. Postoperative jitter (cut off > 1.60) in MDVP had a good specificity, 90%, but only 50% sensitivity. Combining all the GRBAS and MDVP variables with P < 0.05 in the ROC analysis yielded a test with 100% sensitivity and 55% specificity. Conclusions Physician-based perceptual voice assessment has a high sensitivity for detecting postoperative VFP, but the specificity is poor. The risk of VFP is low in patients with completely normal voice at discharge. However, routine laryngoscopy after thyroid and parathyroid surgery is still the most reliable exam for VFP screening.
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Affiliation(s)
- Maria Heikkinen
- Department of Otorhinolaryngology - Head & Neck Surgery, Kuopio University Hospital, PL 100, 70029, Kuopio, Finland. .,Institute of Clinical Medicine, University of Eastern, Kuopio, Finland.
| | - Elina Penttilä
- Department of Otorhinolaryngology - Head & Neck Surgery, Kuopio University Hospital, PL 100, 70029, Kuopio, Finland.,Institute of Clinical Medicine, University of Eastern, Kuopio, Finland
| | - Mari Qvarnström
- Department of Phoniatrics, Kuopio University Hospital, Kuopio, Finland
| | - Kimmo Mäkinen
- Institute of Clinical Medicine, University of Eastern, Kuopio, Finland.,Heart Center, Kuopio University Hospital, Kuopio, Finland
| | - Heikki Löppönen
- Department of Otorhinolaryngology - Head & Neck Surgery, Kuopio University Hospital, PL 100, 70029, Kuopio, Finland.,Institute of Clinical Medicine, University of Eastern, Kuopio, Finland
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15
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Ng SK, Li HN, Chan JYK, Wong EWY, Vlantis AC. A useful landmark to locate the external branch of the superior laryngeal nerve during thyroidectomy. Gland Surg 2020; 9:647-652. [PMID: 32775254 DOI: 10.21037/gs.2020.03.25] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background To determine whether the insertion of the sternothyroid muscle onto the oblique line of the thyroid cartilage can be used to reliably locate the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy. Methods This is a prospective descriptive case series. The EBSLN was identified and confirmed with a nerve stimulator during thyroid surgery. The entry point of the EBSLN into the inferior constrictor/cricothyroid muscle was measured in relation to the insertion and anterior border of the sternothyroid muscle. The perpendicular distance from the insertion of the sternothyroid muscle onto the oblique line was designated the vertical distance (VD) of the nerve entry point (NEP), and the perpendicular distance from the anterior border of the sternothyroid muscle was designated the horizontal distance. Results Ninety patients underwent 130 thyroid lobectomies (60 female, 30 male) (mean age 53.5 years, range, 18-91 years). An attempt to identify the nerve was made in 127 thyroid lobectomies. The EBSLN was identified in 111 cases (87.4%). The mean VD of the NEP from the muscle insertion was 1.1 mm (SD 1.1 mm, range, 0-5 mm) and the mean horizontal distance (HD) was 9.5 mm (SD 3.8 mm, range, 2-21 mm). Conclusions The EBSLN muscle entry point usually lies 1.1 mm from the sternothyroid insertion onto the oblique line, and 5-12 mm from the anterior border of the muscle. These useful landmarks allow the nerve to be consistently located, identified and preserved during thyroid surgery prior to ligating the superior thyroid vessels.
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Affiliation(s)
- Siu-Kwan Ng
- Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
| | - Hok-Nam Li
- Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
| | - Jason Ying-Kuen Chan
- Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
| | - Eddy W Y Wong
- Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
| | - Alexander C Vlantis
- Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
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16
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Zhang D, Wang T, Kim HY, Wang P, Dionigi G, Pino A, Sun H. Strategies for superior thyroid pole dissection in transoral thyroidectomy: a video operative guide. Surg Endosc 2020; 34:3711-3721. [PMID: 32382884 DOI: 10.1007/s00464-020-07577-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 04/17/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND The dissection of the superior thyroid gland pole is challenging when using the in TransOral Endoscopic Thyroidectomy Vestibular Approach (TOETVA) due to (a) the cranio-caudal approach, (b) cranial-caudal view, and (c) the restriction of maneuverability inside the narrow neck air pocket. METHODS In this paper and operative video guide, a series of TOETVA's tips and tricks are presented with an emphasis on the strategies for a safe approach to the superior thyroid gland pole structures. RESULTS Management of the upper thyroid pole structures includes: (a) use of a 5 mm/30°-45° endoscope; (b) retraction ports up to the limit of the lower jaw edge; (c) lateral retraction of 1/3 of the cranial strap muscles; (d) isthmectomy; (e) cutting the sternothyroid muscle cranially for 1 cm; (f) retraction of the thyroid upwards and laterally; (g) monitoring the external branch of the superior laryngeal nerve, and (h) sealing individual vessel branches. CONCLUSION Access to the superior thyroid pole space through the TOETVA approach presents some challenges, particularly when accessing thyroid vessels or nodules located or displaced more cranially. Strategies that enhance a critical view of the superior thyroid gland structures can protect them from damage and have the potential to improve the safety of the TOETVA and decrease potential conversion rates.
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Affiliation(s)
- Daqi Zhang
- Division of Thyroid Surgery, Jilin Provincial Key Laboratory Of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine On Differentiated Thyroid Carcinoma, China-Japan Union Hospital Of Jilin University, 126 Xiantai Blvd, Changchun city, Jilin province, People's Republic of China
| | - Tie Wang
- Division of Thyroid Surgery, Jilin Provincial Key Laboratory Of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine On Differentiated Thyroid Carcinoma, China-Japan Union Hospital Of Jilin University, 126 Xiantai Blvd, Changchun city, Jilin province, People's Republic of China
| | - Hoon Yub Kim
- Department of Surgery, KUMC Thyroid Center, Korea University Hospital, Korea University College of Medicine, Seoul, Korea
| | - Ping Wang
- Department of Thyroid Surgery, School of Medicine, The Second Affiliated Hospital of Zhejiang University, Hangzhou, People's Republic of China
| | - Gianlorenzo Dionigi
- Division for Endocrine and Minimally Invasive Surgery, Department of Human Pathology in Adulthood and Childhood "G. Barresi", University Hospital G. Martino, University of Messina, Messina, Italy
| | - Antonella Pino
- Division for Endocrine and Minimally Invasive Surgery, Department of Human Pathology in Adulthood and Childhood "G. Barresi", University Hospital G. Martino, University of Messina, Messina, Italy.
| | - Hui Sun
- Division of Thyroid Surgery, Jilin Provincial Key Laboratory Of Surgical Translational Medicine, Jilin Provincial Precision Medicine Laboratory of Molecular Biology and Translational Medicine On Differentiated Thyroid Carcinoma, China-Japan Union Hospital Of Jilin University, 126 Xiantai Blvd, Changchun city, Jilin province, People's Republic of China.
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17
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Naytah M, Ibrahim I, da Silva S. Importance of incorporating intraoperative neuromonitoring of the external branch of the superior laryngeal nerve in thyroidectomy: A review and meta-analysis study. Head Neck 2019; 41:2034-2041. [PMID: 30706616 DOI: 10.1002/hed.25669] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 12/17/2018] [Accepted: 01/15/2019] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Voice changes are frequently reported after thyroidectomy due to injury to the external branch of the superior laryngeal nerve (EBSLN) and paralysis of the cricothyroid muscle, The objective is to evaluate the advantage of intraoperative neuromonitoring (IONM) in identifying EBSLN during thyroid surgery. METHODS Data sources were MEDLINE, PubMed, Web of Science, and Cochrane Library from January 1, 1995, through July 1, 2018. Published studies of adult patients who had thyroid surgery and an attempt to identify EBSLN done by conventional methods and/or IONM were selected. RESULTS Seven studies met all inclusion criteria. Patients who had IONM during thyroid surgery had a significantly increased number of identified EBSLN at risk, compared to the control group. CONCLUSION The use of IONM during open thyroid surgery increases EBSLN identification/visualization, and hence it may decrease the incidence of post-thyroidectomy voice disorders.
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Affiliation(s)
- Mai Naytah
- Department of Otolaryngology-Head and Neck Surgery, Royal Victoria Hospital, McGill University, Montréal, Québec, Canada
- Department of Otolaryngology-Head and Neck Surgery, King Fahd Hospital, Ministry of Health, Jeddah, Kingdom of Saudi Arabia
| | - Iman Ibrahim
- Department of Otolaryngology-Head and Neck Surgery, Royal Victoria Hospital, McGill University, Montréal, Québec, Canada
- Audio-vestibular Medicine Unit, Department of Otolaryngology-Head and Neck Surgery, Kasr AlAini Hospital, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Sabrina da Silva
- Department of Otolaryngology-Head and Neck Surgery, Jewish General Hospital, McGill University, Montréal, Québec, Canada
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18
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Intraoperative Neural Monitoring in Endoscopic Thyroidectomy Via Bilateral Areola Approach. Surg Laparosc Endosc Percutan Tech 2019; 28:303-308. [PMID: 29889110 DOI: 10.1097/sle.0000000000000542] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of this report was dual: (a) to describe the step by step standardized intraoperative neural monitoring (IONM) procedure for recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve focusing on percutaneous IONM method, and (b) evaluation and outcomes of intermittent IONM in 237 endoscopic thyroidectomy via bilateral areolar approach cases. MATERIALS AND METHODS A 10-mm curved incision is made along the margin of the right areola at the 2 to 4 o'clock position for the 30-degree endoscope. Bilaterally 5-mm incisions are required on the edges of the areola at the 11 to 12 o'clock positions as accessory operating ports. Ball-tip, monopolar, single-use, standard stimulating probe with a 10-cm handle and 9-cm shaft is adopted percutaneously for IONM. As reference, on the dominant thyroid lesion side, a 0.5-cm circle is drawn with the center at the intersection of a line 2-cm lateral to the anterior median line and a line 2-cm above the line connecting the bilateral clavicular heads. After ensuring with ultrasonography that no vessels are within the puncture passage, the skin is pierced with an 18-G syringe needle. After withdrawing the needle, the probe is carefully inserted through the tract. IONM is performed according to standards of equipment set up, anesthesia, tube positioning verification tests, and electromyography determinations. RESULTS A total of 277 nerves at risk were favorably monitored with percutaneous probe stimulation. RLN, vagus nerve, and external branch of the superior laryngeal nerve were successfully determined. There were no instances of IONM malfunction, equipment displacement, or interference with the other endoscopic instruments. IONM probe insertion incision determined no scarring or morbidity in the neck. The incidence of RLN monolateral temporary palsy was 6%. CONCLUSIONS Standardized monitoring in endoscopic thyroidectomy via bilateral areolar approach is feasible. IONM was implemented by means of percutaneous stimulating probe.
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19
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Zhao Y, Li C, Liu X, Zhou L, Zhang D, Xin J, Wang T, Li S, Sun H, Dionigi G. Investigation on EMG Profiles of the Superior Laryngeal Nerve in a In Vivo Porcine Model. J INVEST SURG 2019; 33:596-604. [PMID: 30644804 DOI: 10.1080/08941939.2018.1547462] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND The electromyographic (EMG) profiles of external branch of the superior laryngeal nerve (EBSLN) have been defined and the optimal intensity of the stimulation of EBSLN in an in vivo porcine model has been explored. MATERIALS EMG was simultaneously registered by the surface of endotracheal tube and needle electrodes by applying a monopolar stimulation probe in 12 piglets (22 EBSLNs). Vagal nerve (VN), RLN and EBSLN were excited to record the EMG tracings and cricothyroid muscle twitch (CTM). VN, RLN and EBSLN were stimulated from 0.1 to 1.0 mA. Cmin and Cmax have been defined as the minimum and maximal stimulation to evoke an EMG response. RESULTS The stimulation resulted in a dose-response curve. Cmin were 0.19 mA (0.04-0.4), 0.19 mA (0.08-0.3) and 0.21 mA (0.1-0.4) for EBSLN, RLN and VN (p > 0.05) respectively. Cmax were 0.6 mA along with an amplitude value of 396 ± 330 μV, 0.5 mA including 1058 ± 382 μV, 0.8 mA coupled with 870 ± 382 μV, equally for EBSLN, RLN and VN (p > 0.05) respectively. No asymmetry of amplitude responses each side for EBSLN, RLN and VN (p = 0.317, p = 0.203 and p = 0.468, respectively) was noted. The amplitudes of EBSLN were significantly lower than RLNs and VN (42% of RLN and 50% of VN amplitude rates). Also, CTM twitch was always detectable with the stimulation of EBSLN. CONCLUSIONS Cmin and Cmax of EBSLN were comparable to RLN and VN standards. The amplitude stimulus-response curves of RLN, VN and EBSLN were highly variable. It has been suggested to apply a stimulation of 1.0 mA and a visual appreciation of CTM twitch for the identification of EBSLN.
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Affiliation(s)
- Yishen Zhao
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Changlin Li
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Xiaoli Liu
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Le Zhou
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Daqi Zhang
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Jingwei Xin
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Tie Wang
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Shijie Li
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Hui Sun
- Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Jilin Provincial Key Laboratory of Surgical Translational Medicine, Changchun City, China
| | - Gianlorenzo Dionigi
- Division for Endocrine and Minimally Invasive Surgery, Department of Human Pathology in Adulthood and Childhood ''G. Barresi'', University Hospital G. Martino, University of Messina, Messina, Italy
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Surgical anatomy of the external branch of the superior laryngeal nerve: a systematic review and meta-analysis. Langenbecks Arch Surg 2018; 403:811-823. [PMID: 30430230 DOI: 10.1007/s00423-018-1723-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 10/22/2018] [Indexed: 01/12/2023]
Abstract
PURPOSE To provide a comprehensive evidence-based assessment of the anatomical characteristics of the external branch of the superior laryngeal nerve (EBSLN). MATERIALS AND METHODS A thorough systematic search was performed on the major electronic databases PubMed, EMBASE, Cochrane library, and ScienceDirect to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcomes were the EBSLN identification rate (total number of EBSLN identified divided by the total number of dissected hemilarynges) and the prevalence of various EBSLN types. RESULTS A total of 56 studies (n = 13,444 hemilarynges) were included. The overall pooled EBSLN identification rate was 89.24% (95% CI 85.49-92.49). This rate was higher for cadaveric (95.00%; 95% CI 89.73-99.35) compared to that reported in intraoperative studies (86.99%; 95% CI 82.37-91.01). Significantly higher identification rates were reported for studies in which intraoperative nerve monitoring was used (95.90%; 95% CI 94.30-97.25) compared to those which only relied on direct visual identification of the EBSLN (76.56%; 95% CI 69.34-83.08). Overall, Cernea type IIa (nerves crossing the superior thyroid artery less than 1 cm above the upper edge of the superior thyroid pole) and Friedman type 1 (nerves running their entire course superficial to the inferior pharyngeal constrictor) were the most prevalent (41.84%; 95% CI 33.28-48.08 and 50%; 95% CI 29.90-65.62, respectively). The combined prevalence of Cernea IIa and IIb (nerves crossing the superior thyroid artery below the upper edge of the superior thyroid pole) was higher in intraoperative studies compared to that in cadaveric studies (64.3% vs 49.4%). The EBSLN coursed medial to the superior thyroid artery in 70.98% (95% CI 55.14-84.68) of all cases. CONCLUSION The use of intraoperative nerve monitoring improves EBSLN identification rates. In light of the highly variable anatomical patterns displayed by the EBSLN, thorough pre-operative knowledge of its anatomy can be crucial in minimizing incidences of its iatrogenic injury.
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A Review of Methods for the Preservation of Laryngeal Nerves During Thyroidectomy. MEDICAL BULLETIN OF SISLI ETFAL HOSPITAL 2018; 52:79-91. [PMID: 32595378 PMCID: PMC7315061 DOI: 10.14744/semb.2018.37928] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 11/20/2022]
Abstract
The recurrent laryngeal nerve (RLN) provides motor innervation to the abductor and adductor muscles of the vocal cord, whereas the external branch of the superior laryngeal nerve (EBSLN) provides motor innervation to the cricothyroid muscle, which is the tensor muscle of the vocal cord. Both the RLN and the EBSLN are anatomically close to the thyroid and are therefore at risk of injury during thyroidectomy. These 2 laryngeal nerves must be carefully preserved during surgery to ensure that the function of the vocal cord is not impaired. Currently, complete exposure of the RLN during thyroidectomy is accepted as the gold standard method for the preservation of RLN. Sufficient knowledge of surgical anatomy, clinical experience, and meticulous surgical techniques are key factors in the identification and safe dissection of the RLN. During a thyroidectomy, the RLN can be identified using four different approaches, depending on the type of thyroid growth and choice of the surgeon: There are lateral, inferior, superior, and medial approaches. The lateral approach is the most commonly used technique in primary thyroid surgery. The RLN is usually found by dissection around the inferior thyroid artery at the level of the middle lobe of the thyroid. RLN is generally found at the site of its entry into the neck region devoid of scar formation when the inferior approach is used especially in cases with secondary surgery. The superior approach is recommended for patients with an huge goiter or large substernal goiter. In this approach, the upper pole of the thyroid is first released and then pulled forward and laterally, and the RLN is exposed on the nerve’s entry point (NEP), into the larynx, under the cricopharyngeus muscle. The medial approach is preferred for patients with substernally or retropharyngeally enlarged goiters. In this approach, the isthmus is first dissected and divided, and then the isthmus and the medial part of the lobe are dissected away from the trachea to reveal the anterolateral part of the trachea. The fibers between the lateral aspect of the second or third tracheal rings and the thyroid, and the fibers of the Berry ligament are gradually dissected cranially, to allow RLN to enter into the field of view lateral to the trachea. The preservation of the anatomical integrity of the RLN does not indicate that its functional integrity is also preserved. IONM is a tool for the functional assessment of RLN, and so this method is an addition to visually identifying RLN, which is the gold standard. IONM significantly contributes to visual identification of the RLN, determination of its anatomical variations, intraoperative recognition of RLN injury, prevention of bilateral vocal cord paralysis, and detection and preservation of electrical activity in the nerve in patients with preoperative vocal cord paralysis. Although there is no standardized method for the preservation of the EBSLN, 3 methods have been defined during the release of the upper pole of the thyroid. These methods involve dividing the branches of the superior thyroidal artery one by one on the capsule without visually identifying the EBSLN, searching and visually identifying the EBSLN before the dissection of the upper pole vessels, or detecting the EBSLN and dissecting the upper pole under the guidance of IONM. IONM also significantly contributes to the detection and confirmation of the EBSLN and dissection and preservation of the upper pole of the thyroid gland.
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Abstract
Introduction Anatomical studies on human cadavers have established anastomoses between laryngeal nerves. However, we need to functionally identify motor communication via these anastomoses between the recurrent laryngeal nerve (RLN) and the external branch of the superior laryngeal nerve (EBSLN) in living bodies. We aim to establish motor interconnections using intraoperative nerve monitoring (IONM). Methods IONM of 112 EBSLNs and RLNs in 62 thyroidectomy cases was used to establish motor functions of laryngeal nerves. Electrophysiological parameters were recorded, and cricothyroid muscle (CTM) contraction was observed after stimulation of laryngeal nerves. Results Eighty (71.4%) EBSLNs were visually identified, and 109 (97.3%) EBSLNs were functionally identified with CTM contraction. Stimulation of 74 (67.9%) EBSLNs induced contraction of laryngeal muscles and generated wave amplitude from intrinsic laryngeal musculature. The stimulation of the RLN induced CTM contraction in 65 (58%) of the 112 muscles. The mean conductivity powers of the EBSLN and of the RLN to intrinsic laryngeal musculature were calculated as 231.3 µV and 1354.5 µV, respectively. Conclusion Recordable waveform amplitude with EBSLN stimulation yielded motor relations between laryngeal nerves. CTM contraction after stimulation of the RLN confirmed these relations. These results of IONM established motor interconnections between superior and inferior laryngeal nerves in the majority of patients. The EBSLN may have an effect on motor innervations for intrinsic laryngeal muscles via motor interconnections.
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Affiliation(s)
- Emin Gurleyik
- Department of Surgery, Duzce University Medical Faculty
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23
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Potenza AS, Araujo Filho VJF, Cernea CR. Injury of the external branch of the superior laryngeal nerve in thyroid surgery. Gland Surg 2017; 6:552-562. [PMID: 29142848 DOI: 10.21037/gs.2017.06.15] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The external branch of the superior laryngeal nerve (EBSLN) innervates the cricothyroid muscle (CTM) to promote lengthening and thinning of the vocal fold, thus increasing voice pitch. The close relation with the superior thyroid vessels (STV) puts the EBSLN in risk every time the superior pole of the thyroid is dissected. It travels downward to innervate the CTM, lateral to the thyroid cartilage and to the inferior pharyngeal constrictor muscle (IPCM), being eventually covered by this muscle fibers as it approaches its entry point. During its descending course, the EBSLN curves and crosses the STV posteriorly. The lower this crossing occurs in the neck, the higher the risk of surgical damage to the nerve by transection, traction, entrapment, thermal damage or disrupted blood supply. The chances of surgical trauma are also increased by size and weight of the specimen, shorter neck length and non-white ethnicity. Voice changes following thyroid surgery are common and multifactorial. The actual rate of vocal impairment due to EBSLN injury is unclear, since changes to the everyday speaking voice can be minimal and laryngeal findings are usually subtle and controversial. CTM electroneuromyography (EMG) is the most accurate tool to diagnose abnormal EBSLN conductivity, but it is technically difficult and barely applicable in routine practice. Recommended approaches to prevent injury include: (I) individual distal ligature of the STV by the thyroid capsule; (II) visual identification of the nerve and its trajectory and (III) electrostimulation with either observation of CTM twitch or intraoperative nerve monitoring (IONM) via dedicated endotracheal tube electrodes. There is accumulating evidence that a combination of visual and standardized electrophysiological EBSLN identification with meticulous division of the STV improves preservation rates. IONM bears the additional benefits of prognostication, quantification and documentation of neural function once it allows intraoperative laryngeal EMG.
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Affiliation(s)
- Andre S Potenza
- Department of Surgery, Head and Neck Surgery Service of the Hospital das Clínicas, Faculty of Medicine of the University of Sao Paulo, Sao Paulo, Brazil
| | - Vergilius J F Araujo Filho
- Department of Surgery, Head and Neck Surgery Service of the Hospital das Clínicas, Faculty of Medicine of the University of Sao Paulo, Sao Paulo, Brazil
| | - Claudio R Cernea
- Department of Surgery, Head and Neck Surgery Service of the Hospital das Clínicas, Faculty of Medicine of the University of Sao Paulo, Sao Paulo, Brazil
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Gurleyik E, Gurleyik G. Intraoperative Monitoring of External Branch of the Superior Laryngeal Nerve: Functional Identification, Motor Integrity, and its Role on Vocal Cord Function. J INVEST SURG 2017; 31:509-514. [PMID: 28952819 DOI: 10.1080/08941939.2017.1362489] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE Beside recurrent laryngeal nerve (RLN), protection of the external branch of the superior laryngeal nerve (EBSLN) is required for complication-free thyroid surgery. This study investigates the contribution of intraoperative neuromonitoring (IONM) to identification and motor integrity of the EBSLN. METHODS This prospective study was performed on 245 EBSLNs in 147 patients with thyroid surgery. The rate of visual identification, contribution of IONM to functional localization, the rate and levels of recordable waveform amplitude from vocal cord (VC) movement were determined during surgery. RESULTS 164 (66.9%) EBSLNs were visually identified and additional 74 branches were functionally identified by IONM. Additional identification rate of IONM was 30.2%. Seven (2.9%) EBSLNs could not be identified during surgery. Cricothyroid muscle (CTM) twitch established functional integrity in 97.1% of EBSLNs. Electrophysiological stimulation of 151 (63.4%) EBSLNs created waveform amplitude >100 µV that mean amplitude level was calculated as 186 µV, and an amplitude >300 µV was recorded in 19 of 151 (12.6%) EBSLNs. CONCLUSIONS In addition to visual identification, surgeons can functionally localize the EBSLN with the assistance of IONM that CTM twitch is a reliable evience for functional integrity of the EBSLN. In the majority of patients, stimulation of the EBSLN creates recordable waveform amplitude thus the EBSLN appears to be a second source of motor innervations for intrinsic laryngeal muscles.
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Affiliation(s)
- Emin Gurleyik
- a Department of Surgery , Duzce University, Medical Faculty , Duzce
| | - Gunay Gurleyik
- b Department of Surgery , Haydarpasa Numune Hospital , Istanbul , Turkey
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Aygün N, Uludağ M, İşgör A. Contribution of intraoperative neuromonitoring to the identification of the external branch of superior laryngeal nerve. Turk J Surg 2017; 33:169-174. [PMID: 28944328 DOI: 10.5152/turkjsurg.2017.3645] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 08/10/2016] [Indexed: 11/22/2022]
Abstract
OBJECTIVE We evaluated the contribution of intraoperative neuromonitoring to the visual and functional identification of the external branch of the superior laryngeal nerve. MATERIAL AND METHODS The prospectively collected data of patients who underwent thyroid surgery with intraoperative neuromonitoring for external branch of the superior laryngeal nerve exploration were assessed retrospectively. The surface endotracheal tube-based Medtronic NIM3 intraoperative neuromonitoring device was used. The external branch of the superior laryngeal nerve function was evaluated by the cricothyroid muscle twitch. In addition, contribution of external branch of the superior laryngeal nerve to the vocal cord adduction was evaluated using electromyographic records. RESULTS The study included data of 126 (female, 103; male, 23) patients undergoing thyroid surgery, with a mean age of 46.2±12.2 years (range, 18-75 years), and 215 neck sides were assessed. Two hundred and one (93.5%) of 215 external branch of the superior laryngeal nerves were identified, of which 60 (27.9%) were identified visually before being stimulated with a monopolar stimulator probe. Eighty-nine (41.4%) external branch of the superior laryngeal nerves were identified visually after being identified with a probe. Although 52 (24.1%) external branch of the superior laryngeal nerves were identified with a probe, they were not visualized. Intraoperative neuromonitoring provided a significant contribution to visual (p<0.001) and functional (p<0.001) identification of external branch of the superior laryngeal nerves. Additionally, positive electromyographic responses were recorded from 160 external branch of the superior laryngeal nerves (74.4%). CONCLUSION Intraoperative neuromonitoring provides an important contribution to visual and functional identification of external branch of the superior laryngeal nerves. We believe that it can not be predicted whether the external branch of the superior laryngeal nerve is at risk or not and the nerve is often invisible; thus, intraoperative neuromonitoring may routinely be used in superior pole dissection. Glottic electromyography response obtained via external branch of the superior laryngeal nerve stimulation provides quantifiable information in addition to the simple visualization of the cricothyroid muscle twitch.
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Affiliation(s)
- Nurcihan Aygün
- Department of General Surgery, Şişli Hamidiye Etfal Training and Research Hospital, İstanbul, Turkey
| | - Mehmet Uludağ
- Department of General Surgery, Şişli Hamidiye Etfal Training and Research Hospital, İstanbul, Turkey
| | - Adnan İşgör
- Department of General Surgery, Bahçeşehir University School of Medicine, İstanbul, Turkey
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Uludag M, Aygun N, Kartal K, Besler E, Isgor A. Is intraoperative neural monitoring necessary for exploration of the superior laryngeal nerve? Surgery 2017; 161:1129-1138. [DOI: 10.1016/j.surg.2016.10.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 10/06/2016] [Accepted: 10/06/2016] [Indexed: 11/15/2022]
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Uludag M, Aygun N, Kartal K, Citgez B, Besler E, Yetkin G, Kaya C, Ozsahin H, Mihmanli M, Isgor A. Contribution of intraoperative neural monitoring to preservation of the external branch of the superior laryngeal nerve: a randomized prospective clinical trial. Langenbecks Arch Surg 2016; 402:965-976. [PMID: 28035477 DOI: 10.1007/s00423-016-1544-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 12/16/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE The purpose of this study was to evaluate the effect of intraoperative neuromonitoring (IONM) on the injury rate of the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy. METHODS A total of 133 consenting patients (98 female, 35 male; mean age, 45.6 ± 11.7 years) undergoing thyroidectomy were randomly assigned to 2 groups. In group 1 (n = 65 patients, 105 nerves), superior thyroid pole dissection was performed with no attempt to identify the EBSLN; in group 2 (n = 68 patients, 106 nerves), IONM was used to identify the EBSLN during surgery. EBSLN function was evaluated by intraoperative electromyography of the cricothyroid muscle. The EBSLN Voice Impairment Index-5 (VII-5) was conducted preoperatively and at 1, 3, and 6 months postoperatively. The primary outcome was the prevalence of EBSLN injury. The secondary outcomes were the identification rate of the EBSLN using IONM and changes in postoperative voice performance. RESULTS EBSLN injury was detected in eight (12.3%) patients and nine (8.6%) nerves in group 1 and in one (1.5%) patient and one (0.9%) nerve in group 2 (patients, p = 0.015; nerves, p = 0.010). IONM contributed significantly to visual (p < 0.001) and functional (p < 0.001) nerve identification in group 2. The VII-5 indicated more voice changes in group 1 than 2 at 1, 3, and 6 months postoperatively (p = 0.012, p = 0.015, and p = 0.02, respectively). CONCLUSION IONM contributes to visual and functional identification of the EBSLN and decreases the rate of EBSLN injury during superior pole dissection. Routine use of IONM to identify the EBSLN will minimize the risk of injury during thyroidectomy.
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Affiliation(s)
- Mehmet Uludag
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey.
| | - Nurcihan Aygun
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Kinyas Kartal
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Bulent Citgez
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Evren Besler
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Gurkan Yetkin
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Cemal Kaya
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Hamdi Ozsahin
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Mehmet Mihmanli
- General Surgery, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Adnan Isgor
- General Surgery, Bahcesehir University Medical Faculty, Istanbul, Turkey
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