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Objective: To conduct a systematic description and meta-analysis of the treatment of unilateral vocal cord paralysis（UVCP） with recurrent laryngeal nerve reinnervation through literature search, and to analyze the therapeutic effect of recurrent laryngeal nerve reinnervation on improving vocal function in UVCP. Methods: Electronic databases Pubmed, Web of Science, EMBASE, Cochrane Library, CNKI, and Wanfang databases were searched using relevant keywords and screened in strict accordance with the inclusion and exclusion criteria, and quality evaluations were conducted. Reported treatment outcomes were measured by relevant data extracted from literature, such as auditory perception assessment（GRBAS）, voice handicap index（VHI）, maximal phonation time（MPT）, jitter, shimmer, and noise harmonic ratio（NHR）, etc. Meta-analysis was performed by Revman5.3 and heterogeneity was analyzed using fixed effects or random effects models. Results: Eight articles were included in this study, all of which showed that the postoperative maximum phonation time of patients was significantly prolonged compared to preoperative, while the postoperative GRBAS score, Jitter, Shimmer, and NHR decreased compared to preoperative with statistical significance. Conclusion: The innervation of the internal laryngeal muscle was obtained through the reinnervation of the recurrent laryngeal nerve, which effectively improved the patient's vocal function and had a good long-term therapeutic effect. Although there was no difference in the efficacy of surgical methods for reconstructing the recurrent laryngeal nerve, the anastomosis between ansa cervicalis nerve and the recurrent laryngeal nerve is more ideal. Further randomized controlled studies with longer follow-up periods and larger samples will increase the credibility of their effectiveness., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Objective: Investigates the application and clinical efficacy of ansa cervicalis anterior root-recurrent laryngeal nerve（RLN） anastomosis in the treatment of unilateral vocal fold paralysis（UVFP）. Methods: A prospective study was conducted with 92 UVFP patients admitted to our department from January 2018 to January 2022 who received ansa cervicalis anterior root-RLN anastomosis. The course of nerve injury ranged from 6 to 24 months. Videostroboscopy, voice subjective auditory perceptual assessment（GRBAS）, Voice Handicap Index（VHI-10）, voice objective acoustic analysis and laryngeal electromyography（EMG） were used to evaluate the efficacy of the operation. Results: Videostroboscopy showed that although the movement of vocal cords did not return to normal 12 months after operation, their volume and muscle tension were significantly improved and their positions were adducted to the median or near-median. Also the glottic closure, vocal cord position, vocal cord edge, symmetry and regularity of vocal cord vibration were significantly improved than pre-operation（ P <0.01）. The five indexes of GRBAS（Grade, Roughness, Breathiness, Asthenia, Strain） and VHI-10, as well as voice acoustic parameters（Jitter, Shimmer, NHR） post-operation were significantly reduced, while the maximum phonation time（MPT） was significantly longer（ P <0.01）. The results of laryngeal EMG indicated that the maximum voluntary motor unit recruitment（VMUR） post-operation was significantly recovered（ P <0.01）, which confirmed that the affected laryngeal muscle obtained effective nerve reinnervation. Conclusion: Ansa cervicalis anterior root-RLN anastomosis can effectively improve the voice function of patients which is safe and satisfactory. It is an ideal method for the treatment of unilateral RLN injury., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Objective: Although radiofrequency ablation (RFA) is a safe and effective non-surgical treatment for benign thyroid nodules, injury to the recurrent laryngeal nerve (RLN), is a potential and feared complication. Intermittent voice checks have been proposed to monitor vocal cord (VC) function during RFA, but such assessment is highly subjective and effort-dependent., Methods: We are here reporting the methodological use of flexible laryngoscopy (FL) for VC monitoring during bilateral thyroid RFA treatment. The patient, a 35-year-old woman, was referred to the Endocrinology Unit for subclinical hyperthyroidism due to bilateral autonomously functioning thyroid nodules., Results: At the end of the treatment of the first nodule, the FL performed by an otorhinolaryngologist specialist allowed evaluating VC function and ruling out possible paralysis before proceeding with the contralateral RFA treatment. The patient was awake during the entire procedure and well tolerated the laryngoscopic examination. The TSH serum evaluations performed one month and 9 months after the procedure assessed an euthyroid state (TSH 3.2 mIU/L and 2.8 mIU/L, respectively)., Conclusion: During bilateral thyroid RFA the use of FL for VC monitoring treatment resulted in a safe, easy-to-perform, and effective strategy to minimize and anticipate RLN injury risk in the awake patient. The prevention of RLN damage is advisable in the case of single RFA treatment, while it should be strongly recommended when RFA is performed on bilateral nodules., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Teliti, Occhini, Fonte, Croce, Calì, Ripepi, Carbone, Rotondi and Chytiris.)

Background: Although several surgical landmarks have been proposed to localize the recurrent laryngeal nerve (RLN), there is still no reliable landmark., Aims: To validate the reliability of a novel reference point at the intersection of the inferior border of the cricopharyngeal muscle and the inferior cornu of thyroid cartilage for locating the RLN., Study Design: Cadaver dissection study in the academic department of otolaryngology-head and neck surgery., Methods: Sixty-four RLNs in cadavers were assessed, and measurements of different surgical landmarks in conjunction with the proposed surgical landmark were obtained. Descriptive statistics, Pearson’s chi-squared test, and Student’s t-test were performed to analyze the data using GraphPad Prism (version 9.4.1; Dotmatics, Boston, Massachusetts, USA)., Results: The average distance from the proposed landmark to the RLN was 2.3 ± 0.85 mm. The RLN was located just posterior to the reference point in 95.31% of the cadavers. The RLN passed under the inferior constrictor muscle in 90.63% of the cadavers. There was no statistically significant difference between right- and left-sided RLNs in terms of their relation with the reference point., Conclusion: The proposed reference point can be used as a reliable landmark to locate the RLN. This reference point may help surgeons during difficult thyroidectomy surgeries by providing an additional anatomical landmark.

Background: Involvement of the recurrent laryngeal nerve (RLN) in papillary thyroid carcinoma (PTC) is an important prognostic factor and is associated with a higher risk of recurrence. This study aimed to retrospectively analyze the outcomes of patients treated with hemithyroidectomy (HT) in PTC patients with an exclusive RLN invasion who could not tolerate staged surgery, did not wish to undergo another operation, or had other reasons., Methods: A retrospective review was conducted on 163 patients with PTC and exclusive RLN involvement at our institution between 2013 and 2019. Patients were divided into a total thyroidectomy (TT) group and HT group. The clinicopathologic factors and prognostic outcomes were compared between the two groups. A propensity score-matched analysis was carried out to reduce selection bias, with the following covariates: gender, age, tumor size, multifocality, central lymph node metastasis (CLNM), and RLN resection. The Kaplan-Meier method was used for a comparison of recurrence outcomes., Results: In the baseline data of the 163 PTC patients, tumor size ( p < 0.001), multifocality ( p = 0.011), CLNM ( p < 0.001), and RLN resection ( p < 0.008) in the TT and HT groups differed significantly, whereas age and gender did not differ between the two groups. The TT group reported significantly higher temporary and permanent hypoparathyroidism than the HT group ( p < 0.001 and p = 0.042, respectively). With 72-month median follow-up, 11 (6.7%) patients developed recurrence. After propensity score matching, 24 patients with HT and 43 patients with TT were included. Recurrence-free survival (RFS) in the matched samples showed no difference between the TT and HT groups ( p = 0.092)., Conclusion: Our results indicate that HT may be a feasible treatment for PTC patients with exclusive RLN involvement in specific circumstances without significantly increasing the risk of recurrence. Performing a thorough preoperative examination is crucial to exclude multifocal tumors and lymph node metastasis before undergoing HT.

Background: Lymph nodes along the left recurrent laryngeal nerve (LRLN) is thought to be highly involved in esophageal cancer. Given the unique anatomical positioning of the nerve, performing lymphadenectomy in this region requires advanced techniques within limited working space. Meanwhile, high incidence of morbidity and mortality is associated with lymphadenectomy. Although several methods have been applied to reduce the technical requirement and the incidence of postoperative complication, the optimal method remains controversial., Methods: This study was a single-center, prospective, randomized trial to investigate the utility of lymphadenectomy along the LRLN during the minimally invasive esophagectomy in esophageal squamous cell carcinoma patients by comparing the surgical outcome, postoperative complication, survival rate, and quality of life (QoL) between the retraction method (RM) and the suspension method (SM) in patients with esophageal cancer from June 2018 to November 2020. QoL was assessed according to questionnaire: EQ-5D-5L., Results: Of 94 patients were enrolled and randomized allocated to RM and SM group equally. Characteristics did not differ between groups. The duration of lymph node dissection along LRLN was significant longer in SM group ( P <0.001). No difference was observed about postoperative complications. One of in-hospital death was occurred in each group ( P >0.999). Patients in neither of groups exhibiting difference about 3-year disease-free survival rate ( P =0.180) and overall survival rate ( P =0.430). No difference was observed in postoperative QoL between groups at different time points (all, P >0.05)., Conclusion: Both methods of lymph node dissection along the LRLN during minimally invasive esophagectomy in esophageal squamous cell carcinoma patients are technically feasible and safe. The RM appears more favorable in terms of reducing surgical duration compared to the SM., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: To investigate the application and effect of capillary fascia preservation between the recurrent laryngeal nerve (RLN) and common carotid artery (fascia preservation method) in nerve protection when dissecting right level Ⅵ lymph nodes for patients with papillary thyroid carcinoma. Methods: A retrospective cohort study enrolling 195 patients with papillary thyroid carcinoma undergoing right level Ⅵ lymph node dissection in Beijing Tongren Hospital from March 2021 to August 2022 was carried out. The RLN was dissected by fascia preservation method in study group and by routine method in control group. The intraoperative electrical signal amplitude of the RLN, the number of dissected lymph nodes, and the postoperative complications were recorded and analyzed. Results: A total of 195 patients (study group: 94 cases, control group: 101 cases) were collected. There were 71 males and 124 females, with the median age of 32 (39, 51) years. In the study group, the total number of right level Ⅵ lymph nodes was significantly larger than the number of right Ⅵa level lymph nodes [8 (6, 11) vs 6 (4, 8), P <0.001]. There were no significant differences between the two groups in the number of level Ⅵa or level Ⅵb lymph nodes [Ⅵa: 6 (4, 8) vs 5 (3, 7), P =0.373; Ⅵb: 3 (1, 4) vs 2 (1, 4), P =0.337] and metastasis rate [Ⅵa: 51.1% (48/94) vs 52.5% (53/101), P =0.844; Ⅵb: 12.8% (12/94) vs 15.8% (16/101), P =0.541]. The ratio of electromyography (EMG) amplitude R2 in lower level Ⅵ and entry into larynx (grouped as>90%, 50%~90%,<50%) in the study group was significantly higher than that in the control group ( P <0.001). No significant differences were detected between the two groups in temporary RLN paralysis [1.1% (1/94) vs 2.0% (2/101), P =1.000]. Conclusions: Fascia preservation method can decrease the stimulus and traction to RLN and preserve the capillary network serving RLN. It can thoroughly dissect lymph nodes and decrease the injury of RLN.

Objective: To explore the clinical value of recurrent laryngeal nerve dissection in the surgical treatment for congenital pyriform sinus fistula（CPSF）. Methods: The clinical data of 42 patients with CPSF were retrospectively analyzed. All patients were diagnosed and treated in the First Affiliated Hospital of Guangdong Pharmaceutical University. Results: During the operation, all patients' recurrent laryngeal nerves were dissected successfully, and fistulas were resected completely,no patients had complication of recurrent laryngeal nerve's damage.There were no recurrence cases during the 13 to 48 months of follow-up. Conclusion: The trend of congenital pyriform sinus fistula is closely related to recurrent laryngeal nerve, it's important to dissect the recurrent laryngeal nerve during the operation for congenital pyriform sinus fistula., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Objective: Bilateral selective reinnervation of the larynx aims to restore both vocal cord tone and abductor movements in patients with bilateral vocal cord palsy., Methods: Four females and one male treated by bilateral selective reinnervation of the larynx were included in the present study. In all cases, both posterior cricoarytenoid muscles were reinnervated using the C3 right phrenic nerve root through the great auricular nerve graft, while adductor muscle tone was bilaterally restored using the thyrohyoid branches of the hypoglossal nerve through transverse cervical nerve grafts., Results: After a minimum follow-up of 48 months, all patients were successfully tracheostomy free and had recovered normal swallowing. At laryngoscopy, the first patient recovered a left unilateral partial abductor movement, the second had complete bilateral abductor movements, the third did not show improvements of abductor movements, but symptomatology was improved, the fourth recovered partial bilateral abductor movements and the fifth case did not show improvements and needed posterior cordotomy., Conclusions: Bilateral selective laryngeal reinnervation, although a complex surgical procedure, offers a more physiologic recovery in the treatment of bilateral vocal fold paralysis. Selection criteria still needs to be precisely defined to avoid unexpected failures., (Copyright © 2023 Società Italiana di Otorinolaringoiatria e Chirurgia Cervico-Facciale, Rome, Italy.)

Objective: The recurrent laryngeal nerve (RLN) may be involved by papillary thyroid carcinoma ≤ 1 centimeter (PTC ≤ 1 cm). Current study investigated the predictive factors of RLN invasion in PTC ≤ 1 cm, the risk factors of disease recurrence in RLN invaded cases and the results of surgical management for RLN invasion., Materials and Methods: Data of 374 PTC ≤ 1 cm patients were retrospectively collected. We performed univariate and multivariate analysis to identify predictive factors of RLN invasion and risk factors of disease recurrence. The abilities of factors in predicting RLN invasion were evaluated. Surgical outcomes and recurrence free survival (RFS) of patients were analyzed., Results: A total of 28 patients suffered RLN invasion, among which seven had disease recurrence. Preoperative vocal cord palsy (VCP), gross extrathyroidal extension, larger tumor size and tumor on the dorsal side of thyroid were verified as predictive factors of RLN invasion. RLN involved patients had poorer RFS, but better than those who also had upper-aerodigestive tract invasion. Upper-aerodigestive tract invasion, lateral neck lymph nodes metastasis (LNM) and BRAF V600E mutation were independent risk factors of disease recurrence in RLN invaded cases. Tumor shaving showed better RLN function preservation without increasing recurrent risk., Conclusion: Current study confirmed the rarity of RLN invasion in PTC ≤ 1 cm. Various aggressive features were verified as predictive factors of RLN invasion. Tumor shaving showed superiority in preserving nerve function without increasing recurrent risk. Special attentions should be paid for disease recurrence when RLN invasion accompanied by upper-aerodigestive tract invasion, lateral neck LNM or BRAF V600E mutation.

Treating an acutely injured recurrent laryngeal nerve by primary nonselective laryngeal reinnervation (LR) during thyroidectomy is encouraged to minimize postoperative morbidity. Performing a concurrent transoral temporary injection laryngoplasty (IL) may improve the patient's voice while waiting for the effect of successful reinnervation. Chronological multidimensional voice outcomes (qualitative and quantitative) and combination of the primary nonselective LR with concurrent transoral IL were not explicitly demonstrated in previous cases that published the literature. In this study, the authors presented the multidimensional voice parameters of 3 patients undergoing primary nonselective LR with concurrent IL during thyroidectomy. The parameters were measured at different time points (2 weeks and 1, 3, 6, and 12 months) following the surgery. Laryngeal electromyography was done at 1 to 2 months and 12 months postsurgery. The results showed that the voices, qualitatively and quantitatively, were within normal range at within 3 months postintervention. The parameters were slightly beyond the normal limit at 3 months and returned to normal at 6 months postintervention and beyond. The LEMG depicted evidence of successful reinnervation in which the motor unit was normal comparable to the opposite normal vocal fold.

Introduction and Objectives: This study analyzed the incidence and predictors of lymph node posterior to the right recurrent laryngeal nerve metastasis in T1a papillary thyroid carcinoma of the right lobe., Methods: This was a retrospective cohort study. Patients were selected from those who had received surgical treatment for primary papillary thyroid carcinoma between January 2019 and December 2020. The association between clinicopathologic variables and lymph node posterior to the right recurrent laryngeal nerve metastasis was assessed using univariate and multivariate analyses. Postoperative complications were also described., Results: Lymph node posterior to the right recurrent laryngeal nerve metastasis was present in 6.0% of the 402 study patients. It was the most likely to occur when there were other lymph node metastases, particularly in the lymph node anterior to the recurrent laryngeal nerve. Independent predictors for lymph node posterior to the right recurrent laryngeal nerve metastasis were a tumor size of ≥5.0 mm, a lower pole location, and lymph node anterior to the right recurrent laryngeal nerve metastasis. The rate of persistent vocal cord paralysis was .5%, and no patient developed permanent hypoparathyroidism., Conclusions: Although lymph node posterior to the right recurrent laryngeal nerve metastases of the right lobe T1a papillary thyroid carcinoma is uncommon, the possibility of metastasis should be investigated when there is a positive lymph node anterior to the right recurrent laryngeal nerve in a tumor >5.0 mm in size located in the lower pole. Lymph node posterior to the right recurrent laryngeal nerve dissection is recommended for such tumors.

Objective: To investigate the clinical characteristics and risk factors of postoperative recurrence in papillary thyroid carcinoma (PTC) patients with recurrent laryngeal nerve (RLN) invasion. Methods: The data of PTC patients with recurrent laryngeal nerve invasion treated in Beijing Tongren Hospital, Capital Medical University from January 2006 to December 2019 were retrospectively analyzed. The acoustic parameters were compared between different subgroups. Kaplan-Meier method was used to calculate the overall survival (OS) and the recurrence-free rate (RFS), and univariate and multivariate Cox regression analyses were performed to determine the risk factors for postoperative recurrence. Results: A total of 150 PTC patients were enrolled in the final analysis, including 102 females and 48 males, with an average age of (53.5±13.7) years, and 62 patients (41.3%) aged over 55 years. There were 88 cases with stage Ⅰ, and 62 cases with stage Ⅲ. Fifty-five patients presented with preoperative vocal cord paralysis. There were 75 cases appearing adhesion between tumor or lymph node and recurrent laryngeal nerve while 75 cases presented with direct invasion. The comparisons of acoustic parameters showed that patients with RLN invasion had higher jitter compared with patients without RLN invasion [2.3% (1.4%, 3.2%) vs 1.8% (0.8%, 2.6%), P <0.001]. Moreover, patients with preoperative vocal cord paralysis (VCP) had higher jitter[3.1% (2.2%, 4.6%) vs 2.0% (1.1%, 2.8%), P <0.001] and shimmer [7.1% (4.9%, 9.9%) vs 5.5% (4.2%, 7.3%), P <0.001] and shorter maximum phonation time (MPT) [8.0 (6.0, 10.0) s vs 12.0 (10.0, 15.3) s, P <0.001] compared with patients without preoperative VCP. However, there was no statistical difference in acoustic parameters between cases with RLN adhesion and RLN invasion (all P >0.05). Postoperative follow-up time ranged between 12-196 months, with an average of (65.0±35.9) months. Sixteen patients (10.7%) had recurrence or metastasis, and 8 cases (5.3%) died of recurrence or metastasis. The 5-year OS rate was 95.1%, and the 10-year OS rate was 92.8%. The 5-year RFS rate was 88.9%, and the 10-year RFS rate was 86.2%. Univariate Cox analysis showed that age of onset ≥ 55 years, preoperative recurrent laryngeal nerve palsy, laryngeal, trachea or esophageal invasion were the risk factors for postoperative recurrence of PTC with RLN invasion (all P <0.05). Multivariate Cox analysis showed that age of onset ≥ 55 years ( OR =1.060, 95% CI : 1.011-1.110, P =0.015) was an independent risk factor. Conclusions: Age of onset ≥ 55 years is an independent risk factor for postoperative recurrence in PTC patients with RLN invasion. Preoperative acoustic parameters may provide reference for evaluation of RLN function.

Objective: To investigate the clinicopathological characteristics of papillary thyroid cancer (PTC) and identify risk factors for postoperative recurrence of PTC with recurrent laryngeal nerve (RLN) involvement., Methods: In total, 171 patients (112 women and 59 men, age: 18-80 years, and 65 patients aged ≥ 55) with T4a PTC with RLN involvement, treated at Beijing Tongren Hospital, Capital Medical University, from January 2006 to December 2020, were retrospectively examined. Clinicopathological characteristics, including voice analysis results, and survival outcomes were assessed. The Mann-Whitney U and Kruskal-Wallis H tests were used to analyze differences in acoustic parameters. The Kaplan-Meier method was used to calculate the overall survival (OS) and recurrence-free (RFS) rates. Univariate and multivariate Cox regression analyses were performed of the clinical data., Results: The postoperative follow-up period ranged from 12 to 196 months (mean: 66.18 months). Of the 171 patients, 16 had recurrence and 8 died of thyroid-related diseases. The 5-year OS rate was 95.22%. The 5-year RFS rate was 89.38%. Jitter and shimmer were higher and maximum phonation time was shorter in patients with preoperative vocal cord paralysis (VCP) than in those without RLN involvement, and in those with RLN involvement but without preoperative VCP. Acoustic parameters were similar in patients with no preoperative VCP and those without RLN involvement. Voice analysis results did not differ between cases with RLN adhesion and RLN invasion. Univariate analysis showed that age at onset ≥ 55 years, preoperative RLN palsy, and esophageal invasion were risk factors for postoperative recurrence of PTC with RLN involvement. Multivariate analysis showed that onset age ≥ 55 years (OR 4.52, 95% confidence interval: 1.44-14.19, P = 0.010) was an independent risk factor for recurrence., Conclusions: PTC patients with RLN invasion can achieve good outcomes. Preoperative voice analysis may offer insights into RLN function. Age of onset ≥ 55 years is an independent risk factor for postoperative recurrence in T4a PTC patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chen, Zhong, Hou, Ma, Shi, Feng, He, Lin, Lian, Shen, Wang and Fang.)

Objective: To investigate the feasibility and advantages of Fang's capillary fascia preservation right recurrent laryngeal nerve (RLN) dissection technique (F-R-RLN dissection) with preservation of the capillary network and fascia between the RLN and common carotid artery for greater neuroprotective efficiency compared with traditional techniques., Methods: We retrospectively analyzed 102 patients with papillary thyroid carcinoma undergoing right level VI lymph node dissection in our department from March 2021 to January 2022. Sixty patients underwent F-R-RLN dissection (the experimental group) and 42 patients underwent standard dissection (the control group). The intraoperative electrical signal amplitude ratios of the RLN, the number of dissected lymph nodes, and the preservation rates of the parathyroid glands were recorded and compared between the two groups., Results: The electrical signal amplitude ratio of the lower neck part point of the RLN to the upper laryngeal inlet point in the experimental group was significantly lower than the ratio in the control group ( p = 0.006, Z-score = -2.726). One patient suffered transient RLN paralysis in both groups, but this resolved within 1 month after operation. There were no significant differences between the two groups in terms of the number of level VIa or level VIb lymph nodes dissected, nor in the rate of preservation of the parathyroid glands., Conclusions: F-R-RLN dissection is a thorough dissection technique that is effective at preventing an electrical signal amplitude decrease in the RLN, and at preventing RLN paralysis by preserving its blood supply., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Shi, Xu, Fang, Zhong, Chen, Hou, Ma, Feng, He, Lian and Wang.)

Objectives: Intraoperative neuromonitoring (IONM) is a useful tool to evaluate the function of recurrent laryngeal nerve (RLN) in thyroid surgery. This study aimed to determine the necessity and value of routinely testing the proximal and distal ends of RLN., Methods: In total, 796 patients undergoing monitored thyroidectomies with standardized procedures were enrolled. All 1346 RLNs with visual integrity of anatomical continuity were routinely stimulated at the most proximal (R2p signal) and distal (R2d signal) ends after complete RLN dissection. The EMG amplitudes between R2p and R2d signals were compared. If the amplitude of R2p/R2d ratio reduction (RPDR) was over 10% or loss of signal (LOS) occurred, the exposed RLN was mapped to identify the injured point. Pre- and post-operative vocal cord (VC) mobility was routinely examined with video-laryngofiberscope., Results: Nerve injuries were detected in 108 (8%) RLNs, including 94 nerves with incomplete LOS (RPDR between 13%-93%) and 14 nerves with complete LOS. The nerve injuries were caused by traction in 80 nerves, dissecting trauma in 23 nerves and lateral heat spread of energy-based devices in 5 nerves. Symmetric VC mobility was found in 72 nerves with RPDR ≤50%. The occurrence of abnormal VC mobility (weak or fixed) was 14%, 67%, 100%, and 100% among the different RPDR stratifications of 51%-60%, 61%-70%, 71%-80%, and 81-93%, respectively. Of the 14 nerves with complete LOS, all showed fixed VC mobility. Permanent VC palsy occurred in 2 nerves with thermal injury., Conclusion: Routinely testing the proximal and distal ends of exposed RLN helps detect unrecognized partial nerve injury, elucidate the injury mechanism and determine injury severity. The procedure provides accurate information for evaluating RLN function after nerve dissection and should be included in the standard IONM procedure., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Huang, Lien, Wang, Wang, Hwang, Shih, Wu, Dionigi, Huang and Chiang.)

Objectives: Quantum molecular resonance (QMR) devices have been applied as energy-based devices in many head and neck surgeries; however, research on their use in thyroid surgery is lacking. This study aimed to investigate the safety parameters of QMR devices during thyroidectomy when dissection was adjacent to the recurrent laryngeal nerve (RLN)., Methods: This study included eight piglets with 16 RLNs, and real-time electromyography (EMG) signals were obtained from continuous intraoperative neuromonitoring (C-IONM). QMR bipolar scissor (BS) and monopolar unit (MU) were tested for safety parameters. In the activation study, QMR devices were activated at varying distances from the RLN. In the cooling study, QMR devices were cooled for varying time intervals, with or without muscle touch maneuver (MTM) before contacting with the RLN., Results: In the activation study, no adverse EMG change occurred when QMR BS and MU were activated at distances of 2 mm or longer from the RLNs. In the cooling study, no adverse EMG change occurred when QMR BS and MU were cooled in 2-second intervals or immediately after MTM., Conclusion: QMR devices should be carefully used when performing RLN dissection during thyroid surgery. According to the activation and cooling safety parameters in this study, surgeons can avoid RLN injury by following standard procedures when using QMR devices., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Tseng, Huang, Lin, Wang, Ko, Chuang, Lu, Chang, Randolph, Dionigi, Chang and Wu.)

Thyroid cancer often invades the recurrent laryngeal nerve (RLN), causing vocal cord paralysis. In such patients, the invaded portion of the RLN usually needs to be resected through curative surgery. We attempt to preserve the nerve by performing sharp dissection in such cases. During nerve dissection, an intraoperative nerve monitoring system helps identify the course of the RLN in the fibrous tissue around the tumor or even within the tumor, and also helps evaluate the nerve integrity. Because of extensive dissection, the preserved RLN may become much thinner than its original thickness. We refer to this procedure as "partial layer resection" of the RLN. In our cases, although the dissected RLNs became thinner, we found that vocal cord function recovered in most patients. If the RLN is fully involved by thyroid cancer or response of the vocal cord against electric stimulation to the RLN is lost, we resect the portion of the RLN together with the tumor and repair it using one of the reconstruction techniques. When a unilateral RLN is resected, the vocal cord on that side is paralyzed. Symptoms include hoarseness, mis-swallowing, and short phonation. RLN reconstruction using one of the reconstruction techniques leads to the recovery of phonatory and swallowing function, although the normal motion of the vocal cord on the side of the anastomosis is not restored. We used direct anastomosis, free nerve grafting, ansa cervicalis-RLN anastomosis, and vagus-RLN anastomosis to reconstruct the RLN. Thyroid cancer often invades the RLN near the Berry's ligament. In such patients, surgeons might assume that reconstruction of the RLN may not be possible because the peripheral stump of the RLN cannot be observed. However, if we divide the inferior pharyngeal constrictor muscles along the lateral edge of the thyroid cartilage, the peripheral RLN can be identified, and nerve reconstruction can be performed. We refer to this procedure as "laryngeal approach".In summary, of the patients with thyroid cancer who required resection of the RLN, RLN reconstruction led to the recovery of phonatory function. We suggest that all thyroid surgeons familiarize themselves with these reconstruction techniques., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Masuoka and Miyauchi.)

Background and Objectives : Recurrent laryngeal nerve injury is one of the major complications of thyroidectomy, with the lateral thyroid ligament (Berry's ligament) being the most frequent site of nerve injury. Neuromonitoring during thyroidectomy revealed three possible anatomical regions of the recurrent laryngeal nerve P1, P2, and P3. P1 represents the recurrent laryngeal nerve's caudal extralaryngeal part and is primarily associated with Berry's ligament. The aim of this systematic review is to identify the anatomical region with the highest risk of injury of the recurrent laryngeal nerve (detected via neuromonitoring) during thyroidectomy and to demonstrate the significance of Berry's ligament as an anatomical structure for the perioperative recognition and protection of the nerve. Materials and Methods : This study conducts a systematic review of the literature and adheres to all PRISMA system criteria as well as recommendations for systematic anatomical reviews. Three search engines (PubMed, Scopus, Cochrane) were used, and 18 out of 464 studies from 2003-2018 were finally included in this meta-analysis. All statistical data analyses were performed via SPSS 25 and Microsoft Office XL software. Results : 9191 nerves at risk were identified. In 75% of cases, the recurrent laryngeal nerve is located superficially to the ligament. In 71% of reported cases, the injury occurred in the P1 area, while the P3 zone (below the location where the nerve crosses the inferior thyroid artery) had the lowest risk of injury. Data from P1, P2, and P3 do not present significant heterogeneity. Conclusions: Berry's ligament constitutes a reliable anatomical structure for recognizing and preserving recurrent laryngeal nerves. P1 is the anatomical area with the greatest risk of recurrent laryngeal nerve damage during thyroidectomy, compared to P2 and P3.

Background: Thyroidectomy is a frequently performed surgery for benign and malignant conditions. Nevertheless, one of the most critical complications of thyroidectomy is recurrent laryngeal nerve (RLN) injury leading to vocal cord paralysis. A thorough knowledge of the anatomical variations of RLN and ligation of the related vessels close to their distal branches is critical to avoid injury., Case Presentation: Here, we report the first case of bilateral trifurcation of recurrent laryngeal nerve (RLN) in a 40-year old woman with multinodular goitre. Total thyroidectomy was performed and RLN was preserved bilaterally. Followed by a precise dissection, fine branches were traced penetrating the larynx. We did not observe any further post-operative complications and patient was discharged with desired outcomes., Conclusions: Anatomical variations of the RLN include-bifurcations, trifurcations, relation of RLN with inferior thyroid artery (ITA) and presence of non-recurrent laryngeal nerve. Only RLN dividing at a distance greater than 5 mm (branching point distance) before its entry into the larynx beneath the cricothyroid are said to bifurcate or trifurcate. Approximately 25% of nerves show branching [71%-unilateral and 18%-bilateral bifurcation]. Incidence of unilateral trifurcations have been noted be 0.9% and the rates of bilateral trifurcation and the divisions of the branches is yet to be ascertained. This is the first report of a bilateral trifurcation of RLN, detected in patient with multinodular goitre and hence warrants a precise analysis of variations of the RLN in patients undergoing thyroidectomy, which is critical to prevent RLN injury., (© 2022. The Author(s).)

Background: Aberrant right subclavian artery (ARSA) accompanied by non-recurrent inferior laryngeal nerve (NRILN) is a rare anomaly. In cases of thoracic esophageal carcinoma associated with ARSA and NRILN, surgeons must take extra care not to injury these vessels and nerves. We believe semi-prone thoracoscopic esophagectomy to be a surgical approach that can safely deal with such an anomaly., Case Presentation: A 70-year-old man complained of feelings of chest constriction. Endoscopic examination revealed an esophageal tumor and computed tomography showed an ARSA. We performed semi-prone thoracoscopic esophagectomy for case with ARSA and NRILN. We identified these anomalies during esophagectomy, and we could complete surgery without injury these vessels and nerves. The patient had an uneventful recovery and discharged 22 days after surgery., Conclusions: Semi-prone thoracoscopic esophagectomy for esophageal carcinoma can be performed safely with a wide operative field, and is an excellent procedure for dissecting esophageal carcinoma in patients with ARSA and NRILN., (© 2022. The Author(s).)

Background: The survival benefits of recurrent laryngeal nerve lymph node dissection (RLNLD) in esophageal squamous cell carcinoma (ESCC) are still under debate, and the prognostic value of unilateral RLNLD has been rarely studied. Therefore, the aim of the present study was to investigate the clinical significance and outcomes of RLNLD in ESCC in a large-scale cohort study, to shed light on the outcomes of unilateral RLNLD, and to identify the factors that affect the prognostic outcome of RLNLD., Methods: We retrospectively reviewed 1153 patients with thoracic ESCC who underwent right thoracotomy with lymphadenectomy. The impact of RLNLD on disease-free survival (DFS) and overall survival (OS) was estimated using the Kaplan-Meier method and Cox proportional hazard models. Inverse probability of treatment weighting (IPTW) was performed to adjust for differences in baseline variables in pairwise comparisons. Subgroup analysis of survival and postoperative complications was conducted for selective RLNLD., Results: RLN lymph node (LN) metastasis was independently associated with tumor location and most other LN station metastases. RLNLD was an independent prognostic factor for DFS and OS. Both patients who underwent unilateral and bilateral RLNLD had significantly better DFS and OS than the non-RLNLD patients. Furthermore, pairwise comparisons with IPTW confirmed these results, and we found that patients who underwent bilateral RLNLD had better survival than those who underwent unilateral RLNLD. However, subgroup analysis showed that there was no survival benefit and higher morbidity after bilateral RLNLD for patients with cancer in the lower thoracic esophagus, and elderly and female patients., Conclusion: RLN LN metastasis is very frequent in ESCC, and both unilateral and bilateral RLNLD have considerable survival benefits. Selective RLNLD with better survival and lower morbidity was recommend for some defined subgroups., (© 2022 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Objective: To study terminal bifurcation of recurrent laryngeal nerves (RLNs) with original direction to larynx entry and to decrease the risk of vocal cord paralysis in thyroid patients., Methods: The RLNs of 294 patients (482 sides) were dissected according to the branches into the larynx, and the original direction of each RLN trunk in thyroid surgery was recorded., Results: (1) About 30.9% of the RLNs gave off multiple branches into the larynx. (2) Two and 3 branches of RLNs into the larynx were found in 25.5% and 5.4% of the cases, respectively. (3) In 0.4% or 2 cases, the RLN trunk combined with the inferior branch of the vagus nerve. (4) Nonrecurrent laryngeal nerve appeared in 2 cases. (5) On the left side, 68.0%, 25.6%, and 6.4% of cases were found with 1, 2, and 3 bifurcations of RLN to larynx entry, respectively. On the right side, 69.8%, 25.8%, and 4.4% cases were identified with 1, 2, and 3 bifurcations of RLN to larynx entry, respectively. (6) The combining dissection approach was proved as successful and safe for protecting the RLN with no permanent RLN paresis., Conclusions: Because of the anatomical variation in RLNs with extralaryngeal bifurcation, it is necessary to increase the awareness of surgeons about these variations so as to protect bifurcated nerves in thyroid surgery.

Technological advances in thyroid surgery have rapidly increased in recent decades. Specifically, recently developed energy-based devices (EBDs) enable simultaneous dissection and sealing tissue. EBDs have many advantages in thyroid surgery, such as reduced blood loss, lower rate of post-operative hypocalcemia, and shorter operation time. However, the rate of recurrent laryngeal nerve (RLN) injury during EBD use has shown statistically inconsistent. EBDs generate high temperature that can cause iatrogenic thermal injury to the RLN by direct or indirect thermal spread. This article reviews relevant medical literatures of conventional electrocauteries and different mechanisms of current EBDs, and compares two safety parameters: safe distance and cooling time. In general, conventional electrocautery generates higher temperature and wider thermal spread range, but when applying EBDs near the RLN adequate activation distance and cooling time are still required to avoid inadvertent thermal injury. To improve voice outcomes in the quality-of-life era, surgeons should observe safety parameters and follow the standard procedures when using EBDs near the RLN in thyroid surgery., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wang, Huang, Wu, Lin, Tseng, Liu, Lu, Chang, Chen, Chen, Dionigi, Chiang and Wang.)

Surgeons must visually distinguish soft-tissues, such as nerves, from surrounding anatomy to prevent complications and optimize patient outcomes. An accurate nerve segmentation and analysis tool could provide useful insight for surgical decision-making. Here, we present an end-to-end, automatic deep learning computer vision algorithm to segment and measure nerves. Unlike traditional medical imaging, our unconstrained setup with accessible handheld digital cameras, along with the unstructured open surgery scene, makes this task uniquely challenging. We investigate one common procedure, thyroidectomy, during which surgeons must avoid damaging the recurrent laryngeal nerve (RLN), which is responsible for human speech. We evaluate our segmentation algorithm on a diverse dataset across varied and challenging settings of operating room image capture, and show strong segmentation performance in the optimal image capture condition. This work lays the foundation for future research in real-time tissue discrimination and integration of accessible, intelligent tools into open surgery to provide actionable insights., (© 2021. The Author(s).)

Background: Systematic nodal dissection plays a crucial role in improving survival and staging in resectable non-small cell lung cancer (NSCLC) patients but at the cost of increasing the occurrence of recurrent laryngeal nerve injury. Technology should be improved to protect the recurrent laryngeal nerve (RLN) during surgery., Methods: NSCLC patients who underwent video-assisted thoracic surgery (VATS) surgical treatment by the same surgeon at our hospital from January 2016 to December 2017 were included as the research subjects and were divided into an energy-device group and a non-energy-device group. Their procedures included anatomic pulmonary resection, normative N1 dissection, and systemic N2 dissection., Results: The rate of metastatically involved recurrent laryngeal nerve lymph nodes (RLNLNs) was 5.19% (39/752). Dissection device, side of primary, FEV1, operative time and BMI were independent predictors of recurrent laryngeal nerve injury (RLNI) (hazard ratio (HR) = 3.576, 95% confidence interval (CI): 1.490-8.583, P = 0.004; HR = 0.175, 95% CI: 0.072-0.424, P =  < 0.001; HR = 3.008, 95% CI: 1.30-6.927, P = 0.010; HR = 0.328, 95% CI: 0.136-0.794, P = 0.013; HR = 0.344, 95%CI: 0.147-0.801, P = 0.013, respectively). Patients in the non-energy-device group had significantly less RLNI than the energy-device group (P = 0.016) and nearly half of the non-thermal RLNI recovered in 2 weeks (P = 0.025) whereas most thermal RLNI required 3 months for recovery., Conclusions: Every station of RLNLN had some degree of cancer metastasis in NSCLC patients and when dissecting RLNLNs, dissection device was an independent and artificially controlled predictor of RLNI. Using a non-energy device is a feasible method to protect the RLN as well as an improved recovery time of RLNI.

Objective: To investigate the factors associated with adherence of an enlarged parathyroid gland to the recurrent laryngeal nerve (RLN) and the effectiveness of intraoperative neural monitoring (IONM)., Methods: This single-center retrospective study involved samples from 197 consecutive patients (394 RLNs; 733 parathyroid glands) who underwent parathyroidectomy and transcervical thymectomy between September 2010 and December 2014. The presence of parathyroid gland adhesion to the RLN and the clinical characteristics of patients with and without nerve adhesion were recorded. All patients underwent intraoperative monitoring of the electromyographic responses of the vocal cords using the endotracheal NIM-Response 3.0 system. The patients' postoperative clinical outcomes were recorded., Results: Parathyroid gland adhesion to the RLN was significantly associated with maximum gland diameter (>15 mm), weight (>500 mg), and the presence of nodular hyperplasia. IONM demonstrated a sensitivity of 97.8%, specificity of 43.5%, and accuracy of 94.7% for detecting nerve damage. Parathyroid gland adhesion to 17 RLNs occurred in 3 cases (17.6%) of vocal cord paralysis, whereas the 377 glands without nerve adhesion resulted in vocal cord paralysis in 20 cases (5.3%)., Conclusion: Our findings demonstrated the effectiveness of IONM using endotracheal electromyography in patients who underwent parathyroidectomy for secondary hyperparathyroidism.

Background: In the present study we determine the feasibility of intraoperative neuromonitoring following the administration of a nondepolarizing neuromuscular blocking agent during thyroid operations, as well as the influence of rocuronium on the achievement of optimal vagal stimulation during intraoperative neuromonitoring in thyroid surgery. We further investigate whether accelerometry is a reliable approach to obtaining an ipsilateral vagus signal prior to recurrent laryngeal nerve dissection., Methods: Included in the study were 61 thyroidectomized patients whose demographic data, indications, type of surgery, vagus, and recurrent nerve values before and after resection were obtained. We created five groups of patients based on the twitch values recorded during ipsilateral vagus stimulation prior to the recurrent laryngeal nerve dissection: (1) <10%, (2) 11-25%, (3) 26-50%, (4) 51-75% and (5) >75%., Results: The average electromyography amplitudes of the vagus nerve prior to the determination of the recurrent laryngeal nerve for each group were 552 μV, 463 μV, 543 μV, 513 μV and 551 μV, respectively. No difference between the groups was observed in this regard (p > 0.05)., Conclusion: It can be expected that as soon as the effects of neuromuscular blockers on the peripheral muscles begin to abate, it will be possible to obtain the ipsilateral vagus signal prior to recurrent laryngeal nerve dissection at the desired levels. It can be concluded from this study that accelerometry using the pollicis muscle is an unreliable tool for the interpretation of the proper electromyography signals of the vagus nerve prior to the determination of the recurrent laryngeal nerve., Competing Interests: Declaration of competing interest The authors report no potential financial and non-financial conflicts of interest., (Copyright © 2020. Published by Elsevier Taiwan LLC.)

Aim: Identification of recurrent laryngeal nerve (RLN), performed via different techniques, decreases nerve injury during thyroidectomy. We aimed to evaluate the effect of different anatomic levels at which RLN was identified on postoperative complications., Material and Methods: The patients underwent total thyroidectomy or lobectomy without lymph node dissection were included. Two different surgical methods were performed: thyroidectomy identifying RLN at level of inferior thyroid artery (ITA) (Group 1); at level of Berry's ligament (Group 2). Patients were evaluated with indirect laryngoscopy on 3rd postoperative day, if nerve damage was determined, at each six months. Nerve damage and postop hypocalcemia were accepted transient up to 6th month, permanent after 6th month. Total serum calcium levels were postoperatively measured on 24th and 48th hours, and then monthly., Results: Unilateral and bilateral RLN damage were detected as 4.4% and 2.2% in Group 1; and 8% and 2.67% in Group 2, respectively. The frequency of RLN damage was similar (p=0.62). Postoperative hypocalcemia was significantly higher in Group 1 (p=0.04); hypocalcemia was similar (p=0.149). One patient in Group 1, and 2 patients in Group 2 had f superior laryngeal nerve (SLN) injury. Three patients from each group showed permanent hypocalcemia. One patient in Group 1, and two in Group 2 developed permanent hoarseness., Discussion: RLN injury was similar in both groups, however, temporary hypocalcemia was more frequent in patients undergone thyroidectomy with RLN identification at ITA level., Conclusions: Devascularization of parathyroid glands may be accused. Future studies are needed., Key Words: Recurrent laryngeal nerve, Thyroidectomy.

We adopted a vision-based tracking system for augmented reality (AR), and evaluated whether it helped surgeons to localize the recurrent laryngeal nerve (RLN) during robotic thyroid surgery. We constructed an AR image of the trachea, common carotid artery, and RLN using CT images. During surgery, an AR image of the trachea and common carotid artery were overlaid on the physical structures after they were exposed. The vision-based tracking system was activated so that the AR image of the RLN followed the camera movement. After identifying the RLN, the distance between the AR image of the RLN and the actual RLN was measured. Eleven RLNs (9 right, 4 left) were tested. The mean distance between the RLN AR image and the actual RLN was 1.9 ± 1.5 mm (range 0.5 to 3.7). RLN localization using AR and vision-based tracking system was successfully applied during robotic thyroidectomy. There were no cases of RLN palsy. This technique may allow surgeons to identify hidden anatomical structures during robotic surgery.

Background: In esophageal squamous carcinoma, lymphadenectomy along the left recurrent laryngeal nerve (RLN) is recommended owing to its highly metastatic potential. However, this procedure is difficult due to limited working space in the left upper mediastinum, and increases postoperative complications., Aim: To present a novel method for lymphadenectomy along the left RLN during thoracoscopic esophagectomy in the semi-prone position., Methods: The fundamental concept of this novel method is to exfoliate a bilateral pedicled nerve flap, which is a two-dimensional membrane, which includes the left RLN, lymph nodes (LNs) along the left RLN, and tracheoesophageal vessels, by suspending the esophagus to the dorsal side and pushing the trachea to the ventral side (named "bilateral exposure method"). Then, the hollow-out method is performed to transform the two-dimensional membrane to a three-dimensional structure, in which the left RLN and tracheoesophageal vessels are easily distinguished and preserved during lymphadenectomy along the left RLN. This novel method was retrospectively evaluated in 116 consecutive patients with esophageal squamous carcinoma from August 2016 to February 2018., Results: There were 58 patients in each group. No significant difference was found between the two groups in terms of age, gender, postoperative pneumonia, anastomotic fistula, and postoperative hospitalization. However, the number of dissected LNs along the left RLN in this novel method was significantly higher than that in the conventional method (4.17 ± 0.359 vs 2.93 ± 0.463, P = 0.0447). Moreover, the operative time and the rate of postoperative hoarseness in the novel method were significantly lower than those in the conventional method (306.0 ± 6.774 vs 335.2 ± 7.750, P = 0.0054; 4/58 vs 12/58, P = 0.0312)., Conclusion: This novel method for lymphadenectomy along the left RLN during thoracoscopic esophagectomy in the semi-prone position is much safer and more effective., Competing Interests: Conflict-of-interest statement: The authors have no conflicts of interest to declare., (©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background: The objective of this study was to compare three kinds of lymphadenectomy methods along the recurrent laryngeal nerve (RLN) and assess the safety and effectiveness of the new method., Methods: A total of 194 patients with esophageal cancer who underwent minimally invasive esophagectomy (MIE) at our institution from May 2013 to May 2017 were analyzed retrospectively. According to the method of lymphadenectomy along the left RLN, the patients were divided into three groups: 75 cases underwent the conventional method (A group), 80 cases the skeletonized method (B group) and 39 cases the modified Bascule method (C group). The number of dissected lymph nodes and surgical outcomes were recorded and compared to identify differences among the three groups., Results: The frequency of metastasis to the LRLN lymph node was 18.6% among all patients, and 12%, 20% and 28% in groups A, B and C, respectively. The number of harvested lymph nodes (total/chest/LRLN/LRLN+) in group B and group C were significantly greater than that of group A, but not significant between group B and group C. The hoarseness rate in group C was 15.4%, which was lower than the rate in group B (21.3%) and higher than the rate in group A (13.3%), but there was no statistical significance., Conclusions: The new method for lymphadenectomy along the left RLN during MIE in the semi-prone position is safe and reliable. It provides sufficient lymph node dissection along the left RLN., (© 2019 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Hypoparathyroidism remains one of the most common complications in thyroid surgery. This study aims for an improved understanding of the complexity of the blood supply and the localisation of the parathyroids compared to the two most important intraoperative landmarks: the inferior laryngeal nerve (ILN) and Zuckerkandl's tubercle (ZT). We examined 103 laryngeal compounds to classify the blood supply and the localisation of the parathyroids. For intraoperative localisation we defined a Cartesian coordinate system with the ZT plane as x-axis and the course of the inferior laryngeal nerve as y-axis. The inferior thyroid artery (ITA) mainly supplies the parathyroids, whereas the superior thyroid artery provides a backup supply. It must be pointed out that 8.2% of parathyroids receive their blood directly from the thyroid gland. 73.5% of all parathyroids lie within 1 cm of the ILN and 1 cm cranial and 2.5 cm caudal to the ZT plane. Our described perimeters mark the most crucial areas during surgery and provide the surgeon with an anatomic mapping showing areas of special carefulness needed. One should keep bearing in mind all possible blood supply types of the parathyroids and therefore all branches should be handled with care.

Background/aim: The potential advantages of robot-assisted thoracoscopic esophagectomy (RATE) have yet to be verified. This study focused on the degree of lymph node dissection around the left recurrent laryngeal nerve (RLN)., Patients and Methods: A total of 21 consecutive patients who received RATE (RATE group) and 38 who received conventional thoracoscopic esophagectomy (TE) (TE group), both with extended lymphadenectomy, for thoracic squamous cell esophageal carcinoma, were enrolled in this study. We compared the numbers of lymph nodes dissected from the mediastinum, especially around the left RLN., Results: The median number of lymph nodes dissected from around the left RLN was 6 in the RATE group and 4 in the TE group, and the ratio of the dissected lymph nodes around the left RLN to all lymph nodes was significantly higher in the RATE group (p=0.048)., Conclusion: Our findings indicate that a robot-assisted surgical system enables for more extensive dissection of lymph nodes around the left RLN., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The non-recurrent laryngeal nerve (nRLN) is a rare anatomic variation that every head and neck surgeon must be aware of, in order to avoid intraoperative injury which leads to postoperative morbidity. We are reporting a case of a nRLN in a 47 year old female patient with medullary thyroid carcinoma who was surgically treated with total thyroidectomy and lymph node dissection. Both two inferior laryngeal nerves were identified, fully exposed and preserved along their cervical courses. However, we found that the right inferior laryngeal nerve was non-recurrent and directly arised from the cervical vagal trunk, entered the larynx after a short transverse course and parallel to the inferior thyroid artery. The safety of thyroid operations is dependent on high index of suspicion, meticulous identification and dissection of laryngeal nerves either recurrent or non-recurrent. This leads to minimum risk of iatrogenic damage of the nerves. Complete knowledge of the anatomy of these neural structures, including all their anatomic variations is of paramount importance.

Background: The extent of total thyroidectomy in the management of multinodular goiter remains unclear. Compared to primary thyroidectomy, secondary total thyroidectomy is more difficult to perform and carries a significantly higher risk of postoperative complications such as recurrent laryngeal nerve (RLN) palsy or hypoparathyroidism. In this study, we aimed to evaluate the efficacy and safety of intraoperative carbon nanoparticle (CN) mapping in patients undergoing secondary total thyroidectomy., Methods: We performed a case-matched analysis of a prospectively maintained database using 8 specific criteria to compare perioperative outcomes after primary total thyroidectomy to those after secondary total thyroidectomy with intraoperative CN mapping. The criteria included age, sex, operative procedure, RLN/parathyroid glands (PGs) exploration, preoperative vocal cord calcium abnormalities, and pathological results. Thirty-five patients underwent secondary total thyroidectomy with intraoperative CN mapping due to recurrent thyroid nodules or development of nodules suspicious for malignancy after subtotal thyroidectomy. Fifty exact matches for all 8 criteria were identified from the database in our previous study, which included records of 3078 primary thyroidectomies without CNs. Perioperative outcomes, surgical technique, and complications were analyzed., Results: The RLNs were successfully identified in all 35 patients. Among three patients that experienced slight hoarseness, one had an RLN end-to-end anastomosis with subsequent improvement in the during the 12-month follow-up period. Two patients experienced changes in vocal tone, but recovered after several months. Two patients underwent parathyroid auto-transplantations, and subsequently presented with transient hypocalcaemia. Their symptoms gradually remitted within one year. Except for mean operation time, there were no statistically significant differences in complications between the primary total thyroidectomies and the secondary total thyroidectomy with CNs., Conclusions: Intraoperative CN mapping, expert knowledge of the jugular anatomy, and standardized resection procedures can minimize the incidence of complications such as RLN palsy and hypoparathyroidism after secondary total thyroidectomy., (Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Background: To describe and evaluate a four step systematic approach to dissecting the recurrent laryngeal nerve (RLN) starting at the cricothyroid junction during thyroid surgery (subsequently referred to as the retrograde medial approach)., Methods: All thyroidectomies completed by the senior author between August 2014 and January 2016 were retrospectively reviewed. Patients were excluded if concurrent lateral or central neck dissection was performed. A follow up period of 1 year was included., Results: Surgical photographs and illustrations demonstrate the four steps in the retrograde medial approach to dissection of the RLN in thyroid surgery. Three hundred forty-two consecutive thyroid surgeries were performed in 17 months, including 213 hemithyroidectomies, 91 total thyroidectomies, and 38 completion thyroidectomies. The rate of temporary and permanent hypocalcemia was 13% (95% confidence interval [CI]: 8-20%) and 3% (95% CI: 1-8%) respectively. The rate of temporary and permanent vocal cord palsy was 9% (95% CI: 6-12%) and 0.3% (95%CI: 0.01-2%) respectively. The median surgical times for hemithyroidectomy, total thyroidectomy, and completion thyroidectomy were 39 min (Interquartile range [IQR]: 33-47 min), 48 min (IQR: 40-60 min), and 40 min (IQR: 35-51 min) respectively. 1% of cases required conversion to an alternative surgical approach., Conclusion: In a tertiary endocrine head and neck practice, the routine use of the retrograde medial approach to RLN dissection is safe and results in a short operative time, and a low conversion rate to other RLN dissection approaches.

Background: Vocal fold motion impairment (VFMI) is a well-recognized complication of thyroid and parathyroid surgery. Preoperative counseling requires a thorough understanding of the incidence, risk factors, and value of early diagnosis of postoperative VFMI. Our objective is to describe the incidence of and risk factors for VFMI for a single high-volume academic surgeon, and to assess the utility of immediate postoperative fiberoptic laryngoscopy (FOL) in early diagnosis of VFMI., Methods: Retrospective cohort study of patients undergoing primary thyroid and parathyroid procedures by a single high-volume surgeon at an academic tertiary care center. All patients underwent preoperative and immediate postoperative FOL. The primary outcome was incidence of VFMI, either temporary (<1 year) or permanent (1 year or more). The unit of analysis was number of recurrent laryngeal nerves (RLN) at risk. Risk factors for VFMI were analyzed using logistic regression, reporting unadjusted and adjusted odds ratios (OR and aOR) and 95% confidence intervals (CI)., Results: The study population comprised 1547 patients undergoing 1580 procedures for a total of 2527 nerves at risk, excluding the 27 nerves found to have motion impairment on preoperative FOL. Sixty-seven new incidents of VFMI were identified on postoperative FOL, with an additional six new incidents detected after voice complaints prompted FOL upon follow-up. Thus, the incidence of postoperative VFMI was 2.9% of RLNs at risk (73 of 2527). The sensitivity and negative predictive value of immediate postoperative FOL were 92% and 99.8% respectively. Permanent VFMI occurred in 9 cases (0.4%), 3 of which were from intentional RLN transection for malignancy. Odds of VFMI were significantly lower after parathyroidectomy (aOR = 0.1, 95%CI = 0.01-0.8 compared with hemithryoidectomy) and higher with central neck dissection (aOR = 2.4, 95CI = 1.0-5.9). Among cases of malignancy, odds of VFMI increased significantly with increasing T-stage (adjusted p trend <0.001)., Conclusion: VFMI is rare and usually temporary after primary thyroid and parathyroid procedures, with increased risk associated with larger primary malignancies and the inclusion of central neck dissection. Immediate postoperative FOL is useful for early detection of VFMI that may allow for clear definition of temporary and permanent immobility rehabilitation especially if there is evidence to support early intervention., (Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Background: Because the thoracic esophageal carcinoma has a high metastatic rate to the upper mediastinal lymph nodes, especially along the recurrent laryngeal nerves (RLN), it is crucial to perform a complete lymphadenectomy along the RLN without complications. Although intraoperative neural monitoring (IONM) during thyroid surgery has gained widespread acceptance as a useful tool for visual nerve identification, utilization of IONM during esophageal surgery has not become common. Here, we describe our procedures, focusing on a lymphadenectomy along the RLN utilizing the IONM., Methods: Eighty-seven patients who underwent prone esophagectomy between December 2009 and September 2017 were included in this study. We divided patients into two groups: neural monitoring group (Nm, n = 31) and conventional method group without IONM (Cm, n = 56). We first dissect around the esophagus, preserving the membranous structure; mesoesophagus, which contains tracheoesophageal artery; RLN; and lymph nodes (mesenterization). In Nm group, we next identify the location of the RLN, which runs in the mesoesophagus using IONM before visual contact. Next, we perform lymphadenectomy around the RLN, preserving the nerve itself. Early surgical outcomes were retrospectively compared between two groups., Results: In all 31 cases in the Nm group, we detected the location of the RLN before the visual contact. The sensitivity and specificity of the IONM to detect the RLN paralysis were 67% and 96%, respectively. Postoperative RLN paralysis was observed in 3 cases in the Nm group (9.7%), which was lower than that in the Cm group (32.1%, p = 0.03). Clavien-Dindo grade 2 and over aspiration were seen in 2 (Nm, 6.5%) and 16 (Cm, 28.6%) cases (p = 0.01), respectively. The postoperative hospital stay was shorter in the Nm group (22 days, median) than in the Cm group (39 days, median, p = 0.0002). The number of dissected mediastinal lymph nodes was similar in both groups (25 vs. 20, median, p = 0.12)., Conclusions: The combination of IONM and the concept of the mesoesophagus have substantial advantages in allowing accurate and safe mediastinal lymphadenectomy during prone esophagectomy., (Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Background: Recently, several energy-based devices (EBDs) have been developed and applied in the context of thyroid surgery. EBDs can reduce operation time, blood loss, and postoperative pain. Compared to conventional electrocautery, EBDs operate at a relatively lower temperature and produce minimal lateral tissue damage. Yet, during device operation, the tip of the EBD is hot enough to cause thermal nerve damage, increasing the need for surgeons to be cautious about EBD application. To increase the safety of EBDs, we attached nerve stimulators to the tips of two EBDs and compared them to conventional monopolar nerve stimulation using a porcine model., Methods: Three piglets (30-40 kg) underwent total thyroidectomy after orotracheal intubation with a nerve integrity monitor (NIM) electromyography (EMG) endotracheal tube. Nerve stimulators were attached to two EBDs (Harmonic Focus ® + and LigaSure™). After dissection and identification of six recurrent laryngeal nerves in the three piglets, both of the EBDs with attached nerve stimulators and a conventional monopolar nerve stimulator were applied near the nerve and EMG parameters were recorded using the NIM 3.0 system. The stimulus intensity was varied from 5 mA to 1 mA and the maximum distance and amplitude at which nerve detection was achieved were measured., Results: There were no statistically significant differences between the maximum distance or mean amplitude obtained from nerve stimulators attached to EBDs and those obtained from the conventional nerve stimulator. Additionally, there were no adverse EMG events related to the use of nerve stimulators attached to EBDs., Conclusions: Attachment of a nerve stimulator to an EBD for nerve detection during thyroidectomy was as safe and effective as attachment of a conventional nerve stimulator. Use of a nerve stimulator attachment may reduce the likelihood of EBD-associated nerve damage during thyroid surgery., (Copyright © 2017. Published by Elsevier Ltd.)

Purpose: The recurrent laryngeal nerve lymph nodes (RLN LNs) are among the most common metastatic sites in esophageal cancer, and the dissection of these lymph nodes (LNs) is considered beneficial. The purpose of this study was to evaluate the characteristics of RLN LN metastases from esophageal squamous cell carcinoma, and the effects of these metastases on the prognosis of patients. In addition, we aimed to determine the reasonable range of dissection of regional LNs., Methods: The clinical data from 348 patients who underwent resection for esophageal carcinoma were retrospectively analyzed., Results: Recurrent laryngeal nerve palsy occurred in 37.6% of the patients. In a subgroup of patients with lower esophageal tumors, cervical LN metastases were significantly more common in patients with positive rather than negative RLN LNs. The primary tumor site, tumor differentiation, and tumor invasion depth were factors that significantly influenced RLN LN metastasis. Multivariate analysis revealed that RLN LN metastasis was a significant factor associated with overall survival (OS) and disease-free survival (DFS) (p<0.001)., Conclusion: Metastasis to RLN LNs is a reliable indicator of cervical LN metastasis in middle/lower thoracic esophageal cancer. RLN LN metastasis may act as a prognostic indicator for patients with esophageal squamous cell carcinoma.

A variety of electromyography (EMG) recording methods were reported during intraoperative neural monitoring (IONM) of recurrent laryngeal nerve (RLN) in thyroid surgery. This study compared two surface recording methods that were obtained by electrodes on endotracheal tube (ET) and thyroid cartilage (TC). This study analyzed 205 RLNs at risk in 110 patients undergoing monitored thyroidectomy. Each patient was intubated with an EMG ET during general anesthesia. A pair of single needle electrode was inserted obliquely into the TC lamina on each side. Standard IONM procedure was routinely followed, and EMG signals recorded by the ET and TC electrodes at each step were compared. In all nerves, evoked laryngeal EMG signals were reliably recorded by the ET and TC electrodes, and showed the same typical waveform and latency. The EMG signals recorded by the TC electrodes showed significantly higher amplitudes and stability compared to those by the ET electrodes. Both recording methods accurately detected 7 partial loss of signal (LOS) and 2 complete LOS events caused by traction stress, but only the ET electrodes falsely detected 3 LOS events caused by ET displacement during surgical manipulation. Two patients with true complete LOS experienced temporary RLN palsy postoperatively. Neither permanent RLN palsy, nor complications from ET or TC electrodes were encountered in this study. Both electrodes are effective and reliable for recording laryngeal EMG signals during monitored thyroidectomy. Compared to ET electrodes, TC electrodes obtain higher and more stable EMG signals as well as fewer false EMG results during IONM., (Copyright © 2017. Published by Elsevier Taiwan.)

Aim: To clarify risk factors and long-term progress of postoperative recurrent laryngeal nerve paralysis (PRNP) in patients with esophageal cancer., Patients and Methods: One hundred and twenty-five esophageal cancer patients, who underwent subtotal esophagetomy, including recurrent laryngeal nerve lymphadenectomy, were analyzed. A laryngoscopy was routinely performed to assess the motility of vocal cords., Results: PRNP was detected in 79 patients and 26 (20.8%) patients required medical interventions (Grade II or more by the Clavien-Dindo classification; group II). Forty-one of 66 (62.1%) patients recovered from PRNP with a median postoperative time of 135 days. The three-field lymphadenectomy and long operative time were the independent prognostic factors of group II., Conclusion: Radical operation caused PRNP with grade II or more. The long-term follow-up of vocal cords was necessary to detect patients with either transient or permanent PRNP., (Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The dysphagia and recurrent laryngeal nerve (RLN) palsy are the most common complications of the patients who underwent anterior cervical surgery in the current literature. These morbidities have led to the study of the impact of sidedness in anterior cervical spine surgery. However, many reports documented the left-side was more effective and safe than right-side based on the anatomy. So the right-side approach is more challenging. We retrospectively study 503 patients with cervical degenerative diseases who underwent cervical spinal surgery using anterolateral right-side approach in our spine center from September 1999 to December 2012 and evaluate the efficient and safety of the anterolateral right-side approach to treat the cervical degenerative diseases. The overall mortality rate in our present report was 3.38% (17 of 503 patients). The most common complication which observed in 2.80% of our cases was dysphagia. Postoperatively, there was only one patient with hematoma and died (0.19%) and symptomatic recurrent laryngeal nerve palsy occurred in 0.39% of the cases. The anterolateral right-side anterior approach didn't increase the incidence of the dysphagia and recurrent laryngeal nerve (RLN) palsy., (Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)