Utilidad de la neuromonitorización vagal continua en cirugía tiroidea: experiencia y resultados en un hospital de tercer nivel / The role of continuous vagal intraoperative nerve monitoring in thyroid surgery: experience and results in a third-level hospital

Resumen Objetivo: La lesión del nervio laríngeo recurrente es una grave complicación en cirugía tiroidea. El propósito del presente estudio es analizar la utilidad de la neuromonitorización vagal continua intraoperatoria en un hospital terciario. Materiales y Método: Estudio observacional, analítico y retrospectivo que recoge pacientes intervenidos de cirugía tiroidea con neuromonitorización en un período de 14 meses. La pérdida de señal se define como amplitud final nerviosa < 100 ^V, realizándose laringoscopia postquirúrgica ante la sospecha de lesión nerviosa. El análisis estadístico se realizó con el programa SPSS® V25,0, con p < 0,05. Resultados: Se incluyeron 120 pacientes intervenidos, registrándose en el 24,2% pérdida de señal. Factores de riesgo para lesión fueron bocio intratorácico (OR 5,31; IC 95% 1,56-17,99; p = 0,007), cirugía cervical previa (OR 5,76; IC 95% 0,64-51,97; p = 0,119) y patología maligna (OR 1,44; IC 95% 0,16-12,79; p = 0,743). Fue posible el cambio de estrategia quirúrgica en 7 casos. En el seguimiento posterior se cuantificó parálisis recurrencial transitoria en 27 pacientes y permanente en 4. Discusión: La neuromonitorización parece reducir la incidencia de parálisis laríngea porque aumenta la seguridad en la identificación del nervio recurrente y reduce su manipulación durante la cirugía. Conclusiones: La neuromonitorización intraoperatoria es útil para identificar el nervio laríngeo recurrente y advierte del riesgo potencial de lesión, permitiendo cambiar la estrategia quirúrgica para evitar la parálisis bilateral de cuerdas vocales.

Aim: Recurrent laryngeal nerve injury is a serious complication in thyroid surgery. The purpose of the present study is to analyze the use of intraoperative continuous vagal neuromonitoring in a tertiary hospital. Materials and Method: Observational, analytical and retrospective study that includes patients who underwent thyroid surgery with neuromonitoring in a period of 14 months. Loss of signal is defined as final nerve amplitude < 100 ^V, and postsurgical laryngoscopy is performed due to suspicion of nerve injury. Statistical analysis was performed with the SPSS® V25.0 program, with p < 0.05. Results: 120 operated patients were included, registering loss of signal in 24.2%. Risk factors for injury were intrathoracic goiter (OR 5.31; 95% CI 1.56-17.99; p = 0.007), previous cervical surgery (OR 5.76; 95% CI 0.64-51.97; p = 0.119) and malignant pathology (OR 1.44; 95% CI 0.16-12.79; p = 0.743). A change in surgical strategy was possible in 7 cases. In the subsequent follow-up, transient recurrent paralysis was quantified in 27 patients and permanent in 4. Discussion: Neuromonitoring seems to reduce the incidence of laryngeal paralysis because it increases the security in the identification of the recurrent nerve and reduces its manipulation during surgery. Conclusions: Intraoperative neuromonitoring is useful to identify the recurrent laryngeal nerve and warns of the potential risk of injury, allowing to change the surgical strategy to avoid bilateral vocal cord paralysis.

Application and progress of intraoperative neuromonitoring techniques in robotic thyroid surgery / 中华内分泌外科杂志

Robotic surgical systems are gradually being used in minimally invasive surgery with their advantages of high-definition magnified 3D images, stable surgical field and flexible operation. The change of surgical approach and the narrow operating space in robotic thyroid surgery have made it more difficult to identify and protect the laryngeal nerve, and the application of nerve monitoring has been limited. Many researchers have attempted to improve the monitoring equipment and probe placement to make intraoperative neuromonitoring techniques work well in robotic thyroid surgery. In this paper, we seek effective ways to protect the laryngeal nerve in robotic thyroid surgery, and lay the foundation for a more minimally invasive and standardized development of this technology.

Current research status on pelvic autonomic nerve monitoring in rectal cancer surgery / 中华胃肠外科杂志

Rectal cancer is a common malignant tumor of the digestive tract, and surgery is the main treatment strategy. Disorders of bowel, anorectal and urogenital function remain common problems after total mesorectal resection (TME), which seriously decreases the quality of life of patients. Surgical nerve damage is one of the main causes of the complications, while TME with pelvic autonomic nerve preservation is an effective way to reduce the occurrence of adverse outcomes. Intraoperative nerve monitoring (IONM) is a promising method to assist the surgeon to identify and protect the pelvic autonomic nerves. Nevertheless, the monitoring methods and technical standards vary, and the clinical use of IONM is still limited. This review aims to summarize the researches on IONM in rectal and pelvic surgery. The electrical nerve stimulation technique and different methods of IONM in rectal cancer surgery are introduced. Also, the authors discuss the limitations of current researches, including methodological disunity and lack of equipment, then prospect the future direction in this field.

Modified transcricothyroid electrode recording method for monitoring recurrent laryngeal nerve function during thyroidectomy / 中华内分泌外科杂志

Objective:To study the safety, validity and practicability of the modified trans-cricothyroid needle electrode method for neurmonitoring during thyroidectomy.Methods:115 patients from the Department of Thyroid Surgery in Peking University Shenzhen Hospital scheduled for thyroid surgery were recruited into the group. Two paired needle electrodes were obliquely inserted into the cricothyroid membrane from the angle between the rectus cricothyroid muscle and the inferior margin of thyroid cartilage. The function of recurrent laryngeal nerve (RLN) was localized, exposed and evaluated by standard four-step method (V1-R1-R2-V2) . The vocal cord movement was evaluated by electronic laryngoscope before and after operation, and t-test was used to compare the difference of EMG signal amplitude before and after operation.Results:A total of 130 RLN from 115 patients were recorded effective electromyographic (EMG) signals, including 12 cases of giant goiter with tracheal compression stenosis; 13 cases had repeated adjustments of the position of tracheal intubation electrode during operation, but EMG signals were not satisfactory; 15 cases were with of accidental findings during operation and requiring neurmonitoring, but tracheal intubation electrodes were not used in advance. 75 cases were volunteers. The signals of 3 RLN were lost during operation. On the second day after operation, electronic laryngoscope showed that 2 cases had normal vocal cord movement and 1 case had vocal cord paralysis and no recovery for 6 months follow-up. The EMG signals of other 127 nerves were V1/R1=1857±1718μV/2347±2323μV, V2/R2=1924±1705μV/2450±2345μV. There was no significant difference in EMG signals between pre-operation and post-operation ( t=0.31/0.35, P=0.755/0.725) . The electronic laryngoscope showed normal vocal cord movement before and after operation. During the operation, 2 patients had a little bleeding at the needle electrode insertion point, which stopped after 5 minutes of compression. No electro-acupuncture breakage, infection or local hematoma occurred. Conclusions:The modified trans-cricothyroid needle electrode method had been proved to be safe and feasible for evaluating the function of recurrent laryngeal nerve in thyroid surgery. Besides of unaffected by tracheal conditions, it has good stability, simple implantation and low cost. In thyroid surgery, it can be used as a useful supplement to endotracheal intubation electrode.

Maximum dose of continuous infusion of mivacurium for thyroid surgery under total intravenous anesthesia: a sequential trial of monitoring neurological function in 30 patients / 南方医科大学学报

OBJECTIVE@#To investigate the maximum dose of continuous mivacurium infusion for intraoperative neuromonitoring (IONM) and observe the adverse reactions during thyroid surgery under total intravenous anesthesia (TIVA).@*METHODS@#Thirty patients undergoing IONM during thyroid surgery received continuous infusion of mivacurium at the initial rate of 14.97 μg · kg@*RESULTS@#The EC@*CONCLUSIONS@#In patients undergoing thyroid surgery under TIVA, the EC

Sequential method for determining the maximum dose of mivacurium continuously infused for intraoperative neuromonitoring in thyroid surgery / 南方医科大学学报

OBJECTIVE@#To determine the maximum dose of continuously infused mivacurium for intraoperative neuromonitoring and observe its adverse effects in thyroid surgery.@*METHODS@#Twenty-eight patients undergoing thyroid surgery with intraoperative neuromonitoring received continuous infusion of mivacurium at the initial rate of 5.43 μg?kg?min, and the infusion rate for the next patient was adjusted based on the response of the previous patient according to the results of neurological monitoring. The depth of anesthesia was maintained with sevoflurane and remifentanil during the surgery. The LD50 and 95% of mivacurium were calculated using Brownlee's up-and-down sequential method.@*RESULTS@#The LD50 of continuously infused mivacurium was 8.94 μg?kg?min (95% : 8.89- 8.99 μg?kg?min) during thyroid surgery, which did not affect neurological function monitoring. Transient chest skin redness occurred after induction in 9 patients (32.1%). None of the patients experienced intubation difficulties or showed intraoperative body motions during the surgery.@*CONCLUSIONS@#In patients undergoing thyroid surgery under anesthesia maintained by inhalation and intravenous infusion, the LD50 of mivacurium was 8.94 μg?kg?min (95% : 8.89-8.99 μg?kg?min) for continuous infusion, which does not cause serious adverse effects during the operation.

Surgical treatment of the recurrent laryngeal nerve invaded by thyroid carcinoma / 中华内分泌外科杂志

The incidence of thyroid carcinoma has increased rapidly in recent years and recurrent laryngeal nerve (RLN) was often found invasion by thyroid carcinoma.Surgery is the preferred treatment of thyroid carcinoma at present.How to evaluate the extent of recurrent laryngeal nerve invasion,thereby formulating the proper treatment,has influence on the radical resection of tumor and the quality of life after surgery.Based on the clinical experience of the author and related literature,this article tries to analyze the pattern and the perioperative evaluation method of the RLN invasion,thus to improve the cognition and treatment of RLN,as well as life quality of patients.

Application of intraoperative neuromonitoring in difficult thyroid carcinoma operation / 中华内分泌外科杂志

Objective To explore the value of intraoperative neuromonitoring (IONM) for recurrent laryngeal nerve (RLN) injury during difficult thyroid carcinoma operation.Methods Data of 102 patients admitted from Nov.2012 to Nov.2015 who underwent complex thyroid carcinoma operation were retrospectively analyzed.Among the 102 patients,39 were receiving the first operation due to local advanced thyroid cancer,and 63 were receiving the second operation.According to whether IONM was applied,the patients were divided into the observation group(57 patients) and the control group(45 patients).Difference of the time cost in exposing and dissecting RLN and RLN injury rate between the two groups was compared.Results The time cost in exposing and dissecting RLN was shorter in the observation group ((7.88±1.55)min) than in the control group ((12.60±3.56)min),with statistical difference (t=-2.449,P=0.044).Three patients (5.26％) in the observation group and 7 patients(15.56％) in the control group had temporary RLN injury,with no statistical difference (P=0.161).No one in the observation group and 2 patients (4.44％) in the control group had permanent RLN injury,and the difference had no statistical significance(P=0.192).Conclusions On the basis of normative surgical procedure,IONM technology can reduce the time of exposing and dissecting RLN,and it has practical value in reducing the risk of RLN injury in difficult thyroid carcinoma operation.

Application of intraoperative neuromonitoring during endoscopic thyroidectomy via breast approach / 中华内分泌外科杂志

Objective To explore the technique and significance of intraoperative neuromonitoring (IONM) for scarless in the neck endoscopic thyroidectomy (SET) via breast approach.Methods From Apr.2015 to Oct.2015,101 consecutive patients undergoing SET with IONM were included.During the operation,patients received radical resection of the thyroid cancer by Wang's seven-step method.The lymph nodes in the central area were dissected and Wang's multi-functional separation forceps were implemented for recurrent laryngeal nerve (RLN) positioning,monitoring and protection.Also,time required for RLN positioning and exposure,postoperative transient and permanent RLN damage incidence were calculated to assess the feasibility of IONM under SET.Results Among 101 patients,130 RLNs in total were exposed.The average time required for RLN positioning under IONM was (3.26 ± 1.08)min,with round-nerve management time of (13.95 ± 4.58)min.Nerve signal change happened in 16.9％(22/130) patients.Positive predictive value was 13.6％ and negative predictive value was 100％.The overall accuracy rate was 85.4％.Conclusion IONM during SET is feasible,and can be helpful for the localization and functional protection of RLN and was useful to predict vocal cord paralysis.

Application of intraoperative neuromonitoring technology in protection of external branch of superior laryngeal nerve / 中华内分泌外科杂志

Objective To investigate the application of intraoperative neuromonitoring (IONM) during thyroidectomy for external branch of superior laryngeal nerve(EBSLN).Methods From Jan.2017 to Jun.2017,138 patients undergoing thyroidectomy were randomly divided into monitor group (n=69) and the control group (n=69).The monitor group were used IONM for EBSLN,while the control group were used conventional area protection.Results The overall incidence of EBSLN injury was 1.4％(1/69) in the monitor group,and the overall incidence of EBSLN injury was 11.6％(8/69) in the control group.There was statistical significance between the two groups.Conclusion The application of IONM in thyroidectomy can exactly identify EBSLN,and reduce the possibility of EBSLN injury remarkably.

Clinical significance of applying intraoperative neuromonitoring technology in subtotal thyroidectomy of patients with nodular goiter / 中华内分泌外科杂志

Objective To investigate the clinical effect of intra-operative recurrent laryngeal nerve(RLN) monitoring in subtotal thyroidectomy of patients with nodular goiter.Methods The clinical data of 83 patients with nodular goiter admitted from Jan.2014 to Oct.2017 were analyzed.They were divided into non-monitoring group(38 cases) and the monitoring group (45 cases).9 patients had masses with a maximum diameter larger than 7 cm and 29 patients had masses with maximum diameter between 4 and 7 cm in the non-monitoring group.Among the 38 masses compressing trachea,one case also had esophagus compression.In the monitoring group,the maximal diameter of mass was larger than 7 cm in 15 cases and 4 to 7 cm in 30 cases.All the 32 cases had trachea compression and 2 cases had esophagus compression.All patients underwent routine laryngoscopy preoperatively,suggesting no RLN paralyses.Both groups underwent subtotal thyroidectomy under general anesthesia.Results In non-monitoring group,there were 18 cases with RLN exposed.Five patients had hoarseness after operation,and laryngoscopy showed weakened ipsilateral vocal cord.In the monitoring group,all patients successfully received the surgery and signals V1 were obtained during nerve monitoring.A total of 21 RLN were exposed intraoperatively.Signals V2 were obtained postoperatively,and they showed no significant reduction as compared to signals V1 and no hoarseness occurred.Incidence of RLN injury in monitoring group was significantly lower than that in non-monitoring group (P＜0.05,P=0.04).The rate of RLN injury in the non-monitoring group was higher than that in the monitoring group.Conclusion In the surgery for nodular goiter,intra-operative RLN monitoring can be applied to determine neural function and can effectively reduce the risk of RLN injury.

Current development and considerations about intraoperative neuromonitoring in thyroid surgery / 中华内分泌外科杂志

Since intraoperative neuromonitoring has been invented,and after persistent developing,it has become an adjunct to laryngeal nerve protection and stand as an important role in localization and recognizing,identification of nerve function and injury mechanisms.This technique has been widespread in China in recent years,but lack of standardized application and pitfalls of this intraoperative neuromonitoring itself have become a major issue.Only by proceeding systematic training,promoting standardized procedures,researches and developments,this technique can maximize its potential and benefit both physicians and patients.

Cirugía de tiroides. Revisión histórica y nuevas tecnologías / Thyroid surgery. Historical review, new technologies

El trabajo repasa la evolución histórica en el entendimiento y en el manejo de la cirugía tiroidea. Describe los orígenes de esta cirugía y su ejecución, mucho antes de que se entendiera el funcionamiento de la glándula. Enumera los personajes más trascendentes de esta historia y cómo otras técnicas aplicadas en la cirugía oncológica general se adaptaron a la cirugía de cabeza y cuello. Se mencionan las innovaciones tecnológicas en cirugía tiroidea.

This work reviews the historical evolution of thyroid surgery, its understanding and management. It mentions the origins of this surgical procedure and its execution well before the understanding of the glandular function. The leading persons in this historical field are enumerated; and a review is made of how other techniques applied in surgical oncology were adapted in head and neck surgery. Technological innovations in thyroid surgery are enumerated.

Application of the continuous nerve monitoring in thyroid surgery / 临床外科杂志

The recurrent laryngeal nerve (RLN) injury is one of the most common complications of thyroidectomy,it causes vocal cord paralysis and seriously affects the quality of patients'life post operation.Intermittent intraoperative neuromonitoring (I-IONM) is found to quickly locate the RLN during operation,indentify anatomic variation,assess the neurological function and prognosis,effectively reduce and prevent the RLN injury.Despite that,I-IONM can only detect the RLN after injury when assessing the integrity of RLN in the short period of nerve stimulation.In order to overcome the limitations of Ⅰ-IONM,the continuous intraoperative nerve monitoring (C-IONM) was developed.Here a brief review on the research and progress of C-IONM in thyroid surgery was presented.

Intraoperative neuromonitoring technology in protection of non-recurrent laryngeal nerve / 中华内分泌外科杂志

Objective To investigate the application of intraoperative neuromonitoring (IONM) during thyroidectomy for non-recurrent laryngeal nerve (NRLN).Methods From Oct.2013 to Apr.2016,2846 patients underwent thyroidectomy with the application of IONM,and 11 patients with non-recurrent laryngeal nerve were analyzed.Results 11 cases of NRLN were all accurately identified by IONM,and no injury of NRLN occurred during thyroid surgery.Conclusions NRLN is uncommon in clinical and it is difficult to be predicted before surgery and easy to be injured.The application of IONM can reduce the possibility of NRLN injury remarkably.

Intraoperative Monitoring and Mapping of the Functional Integrity of the Brainstem

The risk of iatrogenic damage is very high in surgical interventions in or around the brainstem. However, surgical techniques and intraoperative neuromonitoring (ION) have evolved sufficiently to increase the likelihood of successful functional outcomes in many patients. We present a critical review of the methodologies available for intraoperative monitoring and mapping of the brainstem. There are three main groups of techniques that can be used to assess the functional integrity of the brainstem: 1) mapping, which provides rapid anatomical identification of neural structures using electrical stimulation with a hand-held probe, 2) monitoring, which provides real-time information about the functional integrity of the nervous tissue, and 3) techniques involving the examination of brainstem reflexes in the operating room, which allows for the evaluation of the reflex responses that are known to be crucial for most brainstem functions. These include the blink reflex, which is already in use, and other brainstem reflexes that are being explored, such as the masseter H-reflex. This is still under development but is likely to have important functional consequences. Today an abundant armory of ION methods is available for the monitoring and mapping of the functional integrity of the brainstem during surgery. ION methods are essential in surgery either in or around the brainstem; they facilitate the removal of lesions and contribute to notable improvements in the functional outcomes of patients.

Intraoperative Monitoring and Mapping of the Functional Integrity of the Brainstem

The risk of iatrogenic damage is very high in surgical interventions in or around the brainstem. However, surgical techniques and intraoperative neuromonitoring (ION) have evolved sufficiently to increase the likelihood of successful functional outcomes in many patients. We present a critical review of the methodologies available for intraoperative monitoring and mapping of the brainstem. There are three main groups of techniques that can be used to assess the functional integrity of the brainstem: 1) mapping, which provides rapid anatomical identification of neural structures using electrical stimulation with a hand-held probe, 2) monitoring, which provides real-time information about the functional integrity of the nervous tissue, and 3) techniques involving the examination of brainstem reflexes in the operating room, which allows for the evaluation of the reflex responses that are known to be crucial for most brainstem functions. These include the blink reflex, which is already in use, and other brainstem reflexes that are being explored, such as the masseter H-reflex. This is still under development but is likely to have important functional consequences. Today an abundant armory of ION methods is available for the monitoring and mapping of the functional integrity of the brainstem during surgery. ION methods are essential in surgery either in or around the brainstem; they facilitate the removal of lesions and contribute to notable improvements in the functional outcomes of patients.

The Applicability of Intraoperative Neuromonitoring in Patients with Preoperative Motor Weakness during Spine Surgery

OBJECTIVE: The purpose of our study is to evaluate the success rate and feasibility of intraoperative neuromonitoring (IONM) focusing on transcranial motor evoked potential (TcMEP) monitoring for patients with preoperative motor weakness in spine surgery. METHODS: Between November 2011 and December 2013, TcMEP and somatosensory evoked potential (SSEP) monitoring were attempted in 130 consecutive patients undergoing spine surgeries for cervical or thoracic cord lesions. Patients ranged in age from 14 to 81 years (mean±standard deviation, 56.7±14.8 years), and 84 patients were male. The success rates of both SSEP and MEPs monitoring were assessed according to the preoperative Medical Research Council (MRC) and Nurick grades. RESULTS: TcMEP was recorded successfully in 0%, 28.6%, 72.3%, and 100% of patients with MRC grades 1, 2, 3, 4, and 5, respectively. SSEP was obtained from 0%, 37.5%, 21.5%, 61.4%, and 85.4% of patients with MRC grades 1, 2, 3, 4, and 5, respectively. TcMEP was recorded successfully in 84% of patients with Nurick grades 1-3 and 26% of patients with Nurick grades 4-5. SSEPs were recorded successfully in 76.3% of patients with Nurick grades 1-3 and 24% of patients with grades 4-5. CONCLUSION: IONM during spine surgery may be useless in patients with MRC grades 1-2, applicable MRC grade 3, and useful MRC grades 4-5. MRC grade 3 is a critical point of indication for application of MEPs. In unmonitorable cases with MRC grade 3, increasing stimulus intensity or facilitation techniques may be considered to improve the usefulness of TcMEP.

Eficacia, seguridad y eficiencia de las nuevas tecnologías en cirugía tiroidea / Effectiveness, safety and efficiency of new technologies in thyroid surgery

Introduction: Surgery of the thyroid gland is the most performed procedure by the endocrine surgeon. In the last years, new techniques have been incorporated in this procedure. Our objective is to analyse the impact of these techniques in our department. Methods: We performed a retrospective and comparative study among three samples of patients submitted for total thyroidectomy. Group I: Sample of 96 patients operated between 2004 and 2007 performing total thyroidectomy. In this period we didn't use ultrasonic scalpel (US) nor intraoperative neuromonitoring (INM). Group II: Sample of 108 patients operated between 2008 and 2010. In this group we used US for hemostasis. Group III: Sample of 82 patients operated between 2011 and 2012. In this group we used both US and INM. The groups are compared: complications, postoperative stay, surgical time and costs per patient. Results: We analysed the following complications: haemorrhage, postoperative hipocalcemia and recurrent nerve palsy. We didn't find significant differences among the samples of patients but there were a less percentage of recurrent palsy in the third group (4.9 percent vs 12.5 and 11.1 percent). We found significant differences when stay, surgical time and costs were analysed. Conclusion: The use of new techniques in thyroid surgery has supposed an improvement not only in the clinic outcomes but in the surgical time.

Objetivo: La cirugía de la glándula tiroides representa el procedimiento más frecuente que realiza el cirujano endocrino. En los últimos años se han ido incorporando nuevas técnicas aplicadas a este procedimiento. El objetivo de nuestro trabajo es analizar el impacto que dichas técnicas han tenido en nuestro servicio. Material y Métodos: Estudio retrospectivo y comparativo entre tres muestras de pacientes a los que se realizó tiroidectomía total. Grupo I: Muestra de 96 pacientes intervenidos entre 2004 y 2007 a los que se realizó tiroidectomía total. En este período no se utilizó bisturí ultrasónico (BU) ni neuromonitorización intraoperatoria (NMI). Grupo II: Muestra de 108 pacientes intervenidos entre 2008 y 2010. En este grupo se realizó hemostasia con BU. Grupo III: Muestra de 82 pacientes intervenidos entre 2011 y 2012. Se utilizó tanto el BU como la NMI. Se comparan los grupos en cuanto a: complicaciones, estancia postoperatoria, tiempo quirúrgico y coste por paciente. Resultados: Las complicaciones analizadas fueron: hemorragia, hipocalcemia postoperatoria y parálisis del nervio laríngeo recurrente. No encontramos diferencias significativas entre los grupos aunque sí hay una menor tasa de parálisis recurrenciales en el tercer período (4,9 por ciento vs 12,5 y 11,1 por ciento). Hemos obtenido diferencias significativas en estancia, tiempo quirúrgico y coste por paciente. Conclusión: La inclusión de las nuevas técnicas en cirugía tiroidea ha supuesto una mejora en los resultados clínicos así como un ahorro de tiempo de quirófano.

Intraoperative neuromonitoring of the recurrent laryngeal nerve during thyroid cancer surgery / 中华内分泌外科杂志

Objective To explore the clinical significance of intraoperative neuromonitoring (IONM)of recurrent laryngeal nerve (RLN) during thyroid cancer surgery.Methods 200 patients undergoing thyroid cancer surgery from Oct.2011 to May 2012 were retrospectively reviewed.The 200 patients were divided into 2 groups:100 patients in group A with IONM and 100 patients in group B without IONM.Results Group A had less RLN exposure time than group B(10.5 vs 15.3 mins,P ＜0.01).Group A had shorter operation time than group B (78.5 vs 82.3 mins).The difference had no statistical significance (P ＞ 0.05).Transient RLN palsy occurred to 5 cases in group A and 11 cases in group B(P＜0.05).Permanent RLN palsy occurred to 1 case in group A.No one in groupB had permanent RLN palsy (P ＞ 0.05).Conclusions IONM can reduce the incidence of transient RLN palsy compared with visualization alone.It is an effective procedure for identifying and protecting RLN in thyroid cancer surgery.