Characteristics of lymph node metastasis of right recurrent laryngeal nerve in thoracic esophageal squamous cell carcinoma / 中华肿瘤杂志

Objective: To understand the characteristics and influencing factors of lymph node metastasis of the right recurrent laryngeal nerve in thoracic esophageal squamous cell carcinoma (ESCC), and to explore the reasonable range of lymph node dissection and the value of right recurrent laryngeal nerve lymph node dissection. Methods: The clinicopathological data with thoracic ESCC were retrospectively analyzed, and the characteristics of lymph node metastasis along the right recurrent laryngeal nerve and its influencing factors were explored. Results: Eighty out of 516 patients had lymph node metastasis along the right recurrent laryngeal nerve, the metastasis rate was 15.5%. Among 80 patients with lymph node metastasis along the right recurrent laryngeal nerve, 25 cases had isolated metastasis to the right recurrent laryngeal nerve lymph node but no other lymph nodes. The incidence of isolated metastasis to the recurrent laryngeal nerve lymph node was 4.8% (25/516). A total of 1 127 lymph nodes along the right recurrent laryngeal nerve were dissected, 115 lymph nodes had metastasis, and the degree of lymph node metastasis was 10.2%. T stage, degree of tumor differentiation and tumor location were associated with right paraglottic nerve lymph node metastasis (all P<0.05). The lymph node metastasis rate along the right recurrent laryngeal in patients with upper thoracic squamous cell carcinoma (23.4%, 26/111) was higher than that of patients with middle (13.5%, 40/296) and lower (12.8%, 14/109) thoracic squamous cell carcinoma (P=0.033). In patients with poorly differentiated ESCC (20.6%, 37/180) the metastasis rate was higher than that of patients with moderately (14.6%, 39/267) and well-differentiated (5.8%, 4/69; P<0.05). The lymph node metastasis rate of patients with stage T4 (27.3%, 3/11) was higher than that of patients with stage T1 (9.6%, 19/198), T2 (19.0%, 16/84) and T3 (18.8%, 42/1 223; P<0.05). Multivariate regression analysis showed that tumor location (OR=0.61, 95% CI: 0.41-0.90, P=0.013), invasion depth (OR=1.46, 95% CI: 1.11-1.92, P=0.007), and differentiation degree (OR=1.67, 95% CI: 1.13-2.49, P=0.011) were independent risk factors for lymph node metastasis along right recurrent laryngeal nerve of ESCC. Conclusions: The lymph node along the right recurrent laryngeal nerve has a higher rate of metastasis and should be routinely dissected in patients with ESCC. Tumor location, tumor invasion depth, and differentiation degree are risk factors for lymph node metastasis along right recurrent laryngeal nerve in patients with ESCC.

Factors predisposing to post thyroidectomy vocal cord paralysis at Ospital ng Maynila Medical Center

Objective@#To determine the prevalence of vocal cord paralysis among post thyroidectomy patients based on severity and laterality, and explore possible associations with age, sex, diagnosis and type of thyroid lesion and surgical procedure.@*Methods@#Design: Cross-sectional study. Setting: Tertiary Government Training Hospital. Participants: Records of patients who underwent thyroidectomy under the Department of Otorhinolaryngology – Head and Neck Surgery of the Ospital ng Maynila Medical Center from January 1, 2014 to June 30, 2021. @*Results@#There were strong associations between the type of lesion and the presence of recurrent laryngeal nerve injury (V=.211, p=.001) and the diagnosis and the presence of RLNI (V=.245, p=.006). There were no significant associations between patient’s sex, age, diagnosis, type of thyroid lesion, surgical procedure with laterality and severity of RLNI. It was notable that all cases of bilateral recurrent laryngeal nerve injury were due to carcinoma only. Patients with malignant tumors were 2.8x (95% CI: 1.48-5.29) as likely to develop post surgical RLNI than those with benign tumors (p=.0015).@*Conclusion@#The factors that had a strong association with the presence of vocal cord paralysis among post-thyroidectomy patients were the diagnosis and type of thyroid lesion. Malignant thyroid lesions (specifically thyroid carcinoma) had a higher incidence of recurrent laryngeal nerve injury compared to benign thyroid lesions. More data from different institutions and including other predisposing factors may confirm our findings.

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.

The value and related complications of lymph node dissection along bilateral recurrent laryngeal nerves in esophageal cancer patients / 中华肿瘤杂志

Esophageal cancer is one of the most common malignant tumors of digestive tract, lymph node metastasis is a frequently encountered metastasis in the esophageal cancer patients. The number of lymph node metastasis is reported as an important prognostic factor, and it also affects the choice of postoperative treatments in the esophageal cancer. It was reported that the recurrent laryngeal nerve lymph nodes are the most common sites of nodal metastasis and need to be completely dissected during the esophagectomy for thoracic esophageal cancers. Dissection of the lymph nodes along bilateral recurrent laryngeal nerves not only improves the accuracy of staging, but also improves postoperative survival of esophageal cancer patients due to reducing the local recurrence. However, it also brings problems such as injury of laryngeal recurrent nerves, and increases postoperative complications such as pulmonary complications and malnutrition due to aspiration and coughing. Therefore, it is necessary to preserve the structure and function of bilateral recurrent laryngeal nerves during esophagectomy through careful manipulations, and minimize the impact of complications in prognosis and quality of life from injury to the recurrent laryngeal nerve.

Lesión del nervio laríngeo recurrente en cirugía tiroidea / Recurring laryngeal nerve injury in thyroid surgery

La lesión del nervio laríngeo recurrente (NLR) es una de las complicaciones más severas en las tiroidectomías. La lesión unilateral genera trastornos disfónicos que se manifiesta por voz débil y una posición paramedial de la cuerda vocal afectada, mientas que la bilateral genera trastornos respiratorios, incluyendo la asfixia. Se ha estimado que la lesión del NLR en las tiroidectomías se encuentra entre un rango de 0.3%- 18.9%. Se ha visto que con el neuromonitoreo intraoperatorio ha disminuido la incidencia de lesión, aunque debemos tener en cuenta un factor muy importante a la hora de solicitarlo y utilizarlo, el económico. La tasa de lesión permanente del nervio laríngeo recurrente debe permanecer por debajo de 1 a 2 %. Sin embargo, existen circunstancias en las cuales los nervios están expuestos a un mayor riesgo y son muchos los factores involucrados en su mecanismo de lesión. Este artículo pretende hacer una revisión del tema enfatizando en la importancia de la preservación de la funcionalidad e integridad de ambos nervios laríngeos recurrentes.

Recurrent laryngeal nerve injury (RLN) is one of the most severe complications in thyroidectomies. Unilateral injury generates dysphonic disorders manifested by weak voice and a paramedial position of the affected vocal cord, while bilateral injury generates respiratory disorders, including suffocation. RLN injury in thyroidectomies has been estimated to be in the range of 0.3% - 18.9%. It has been seen that with intraoperative neuromonitoring the incidence of injury has decreased, although we must take into account a very important factor when requesting and using it, the economic one. The rate of permanent injury to the recurrent laryngeal nerve should remain below 1% to 2%. However, there are circumstances in which the nerves are exposed to greater risk and many factors are involved in their mechanism of injury. This article aims to review the subject, emphasizing the importance of preserving the functionality and integrity of both recurrent laryngeal nerves

Relato de Caso: paralisia unilateral de prega vocal por tuberculose mediastinal / Case report: unilateral vocal fold paralysis by mediastinal tuberculosis

Introdução: A tuberculose (TB) acomete especialmente os pulmões, no entanto, também se tem conhecimento das formas extrapulmonares. Dentre essas, buscamos relatar um caso raro de TB mediastinal localizada em trajeto de nervo laríngeo recorrente (NLR), a qual se manifestou com paralisia de prega vocal (PPV). Relato de Caso: Paciente masculino, 58 anos, apresentando quadro de disfonia. Histórico de exérese de testículo esquerdo e anatomopatológico evidenciando orquiepididimite crônica granulomatosa sugestiva de etiologia tuberculosa. Ex-tabagista e ex-etilista. Realizou, há 15 anos, um tratamento por 6 meses para TB pulmonar. Contactante de paciente bacilífero há três anos. A videolaringoscopia identificou PPV esquerda paramediana. A tomografia computadorizada (TC) de pescoço evidenciou linfonodos calcificados no mediastino superior, fossas supraclaviculares e espessamento de corda vocal à direita. A TC de Tórax apresentou conglomerados sequelares linfonodais calcificados no mediastino e sequela de processo granulomatoso crônico tipo TB em ápices pulmonares. Sorologia de HIV não reagente. Baciloscopia negativa, com amostra insuficiente. Cultura de escarro negativa. Discussão: A PPV esquerda encontrada na videolaringoscopia e TC de pescoço e os achados de TB mediastinal indicaram acometimento do NLR esquerdo pelo processo granulomatoso em seu trajeto, sendo esse, uma reativação de TB ganglionar mediastinal. Fora realizado esquema básico de tratamento para TB, com posterior resolução do quadro de disfonia. Embora a TB torácica seja uma condição comum, a rouquidão devido à PPV é uma complicação raramente associada. Conclusão: Salientamos a importância de estender a investigação ao mediastino na vigência de PPV unilateral, uma vez que a disfunção do NLR pode justificar o quadro.

Introduction: tuberculosis (TB) affects most commonly the lungs; nevertheless, extrapulmonary forms are also known. With that in mind, we intend to report a rare case of mediastinal TB located on the path of the recurrent laryngeal nerve (RLN), manifesting itself with vocal fold paralysis (VFP). Case report: male patient, 58 years old, presenting dysphonia. History of exeresis of the left testicle and anatomopathological showing chronic granulomatous orchiepididimitis, suggestive of tuberculous etiology. Former smoker, ex-alcoholic. Previous treatment for six months due to pulmonary TB, 15 years ago. Bacilli patient contactant for three years. Videolaryngoscopy identified paramedian left VFP. Computed tomography (CT) of the neck showed calcified lymph nodes in the upper mediastinum, supraclavicular fossa, and thickening on the right vocal cord. Chest CT showed calcified lymph node sequels in the mediastinal and Chronic Granulomatous TB-type sequel in pulmonary apices. Non-reactive HIV serology. Negative baciloscopy, insufficient sample. Negative sputum culture. Discussion: the finding of left VFP in videolaryngoscopy and neck CT, associated with the findings of mediastinal TB, indicated that the left RLN's involvement occurred due to the granulomatous process in its path, meaning a reactivation of mediastinal ganglionic TB. A simple treatment schedule for TB had been conducted, with subsequent resolution of the dysphonia. Even though thoracic TB is a common condition, hoarseness due to VFP is a rarely associated complication. Conclusion: we stress the importance of extending the investigation to the mediastinum in case of unilateral VFP since a dysfunction of the RLN is a possible justification of the case.

Ortner's syndrome

Inferior laryngeal nerve palsy is a relatively common entity. Nevertheless, an occurrence as a result of a cardiovascular pathology is rare. In this case, it is called Ortner's syndrome (OS). Aortic diseases are responsible for more than half of cases. Supraaortic vessels disorders are rare causes of OS. In our new report, a non-smoker and non-drinker 70-year-old woman presented with a history of dysphonia since childhood. On direct laryngoscopy, a left vocal cord paralysis was detected and a contrast-enhanced computed tomography showed an aberrant right subclavian artery originating from the left portion of the aortic arch. Its course to its usual site runs behind the esophagus, being also called arteria lusoria. In this particular case, two unusual situations appear together, which contributes to the rarity of the event.(AU)

O tubérculo de Zuckerkandl pode auxiliar na localização do nervo laríngeo inferior durante tireoidectomias? / Can the Zuckerkandl tubercle assist in the location of the inferior laryngeal nerve during thyroidectomies?

RESUMO Objetivo: avaliar se a projeção lateral da glândula tireoide, chamada tubérculo de Zuckerkandl (TZ), pode auxiliar o cirurgião na identificação do nervo laríngeo inferior durante a tireoidectomia convencional aberta. Métodos: estudo prospectivo de 51 pacientes submetidos à tireoidectomia, com um total de 100 lobos tireoidianos ressecados, e observação da presença ou não do TZ em dimensões suficientes para ser identificado sem magnificação de imagem, suas dimensões de base e altura, sua localização na glândula e sua relação anatômica com o nervo laríngeo inferior. Resultados: o TZ estava presente em 68 dos 100 lobos de tireoide analisados (68%). A dimensão média da base foi 6,7mm no lado direito e 7,1mm no lado esquerdo, e a altura média foi 5,7mm no lado direito e 6,1mm no lado esquerdo. Na maioria dos lobos estudados, o tubérculo tinha altura mínima de 5mm (55,9%) sem diferença significativa entre o lobo direito e esquerdo da glândula tireoide. Durante a cirurgia, 100% dos TZ identificados estavam anteriores ao nervo laríngeo inferior, imediatamente abaixo da entrada do nervo na laringe. Conclusão: o TZ é bastante frequente e em dimensões suficientes para ser usado como referência anatômica na localização intraoperatória do nervo laríngeo inferior, próximo à sua entrada na laringe, junto com as demais referências anatômicas.

ABSTRACT Objective: to evaluate whether the lateral projection of the thyroid gland, called Zuckerkandl's tubercle (ZT), can assist the surgeon in identifying the inferior laryngeal nerve during conventional open thyroidectomy. Methods: we conducted a prospective study with 51 patients submitted to thyroidectomy, with a total of 100 resected thyroid lobes, and observed the presence or absence of ZT in sufficient dimensions to be identified without image magnification, its base and height, its location in the gland, and its anatomical relationship with the inferior laryngeal nerve. Results: ZT was present in 68 of the 100 thyroid lobes analyzed (68%). The mean base was 6.7mm on the right side and 7.1mm on the left side, and the average height was 5.7mm on the right side and 6.1mm on the left side. In most of the lobes studied, the tubercle had a minimum height of 5mm (55.9%), with no significant difference between the right and left lobes of the thyroid gland. During surgery, 100% of the identified ZTs were anterior to the inferior laryngeal nerve, just below the nerve entry in the larynx. Conclusion: the ZT is a quite frequent entity and large enough to serve as an intraoperative anatomical reference for the inferior laryngeal nerve, next to its entry in the larynx, along with other anatomical references.

Comparative Analysis of Phase Lag Entropy and Bispectral Index as Anesthetic Depth Indicators in Patients Undergoing Thyroid Surgery with Nerve Integrity Monitoring

BACKGROUND: Most depth of anesthesia (DOA) monitors rely on the temporal characteristics of a single-channel electroencephalogram (EEG) and cannot provide spatial or connectivity information. Phase lag entropy (PLE) reflects DOA by calculating diverse connectivity from temporal patterns of phase relationships. The aim of this study was to compare the performance of PLE and bispectral index (BIS) monitors for assessing DOA during anesthesia induction, nerve integrity monitoring (NIM), and anesthesia emergence. METHODS: Thirty-five patients undergoing elective thyroid surgery with recurrent laryngeal nerve NIM received propofol and remifentanil via target-controlled infusion. After applying PLE and BIS monitors, propofol infusion was initiated at a calculated effect site concentration (Ce) of 2 µg/mL and then increased in 1-µg/mL Ce increments. After propofol Ce reached 5 μg/mL, a remifentanil infusion was begun, and anesthesia induction was considered complete. During NIM, PLE and BIS values were compared at a specific time points from platysma muscle exposure to subcutaneous tissue closure. PLE and BIS values were recorded continuously from preanesthetic state to full recovery of orientation; bias and limits of agreement between monitors were calculated. RESULTS: PLE and BIS values decreased progressively with increasing propofol Ce during anesthetic induction and increased by stages during emergence. The prediction probabilities of PLE and BIS for detecting propofol Ce changes were 0.750 and 0.756, respectively, during induction and 0.749 and 0.746, respectively, during emergence. No aberrant PLE or BIS values occurred during NIM. Correlation coefficients for BIS and PLE were 0.98 and 0.92 during induction and emergence, respectively. PLE values were significantly higher than BIS values at full recovery of orientation. Estimated bias between monitors was −4.16 ± 8.7, and 95% limits of agreement were −21.21 to 12.89. CONCLUSION: PLE is a reasonable alternative to BIS for evaluating consciousness and DOA during general anesthesia and during NIM. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0003490

Development of a Novel Intraoperative Neuromonitoring System Using an Accelerometer Sensor in Thyroid Surgery: A Porcine Model Study

OBJECTIVES: The sensitivity and positive predictive value of widely used intraoperative neuromonitoring (IONM) using electromyography (EMG) of the vocalis muscle in thyroid surgery are controversial. Thus, we developed a novel IONM system with an accelerometer sensor that uses the piezoelectric effect instead of EMG to detect laryngeal twitching. The objective of this study was to evaluate the feasibility and safety of this novel IONM system during thyroid surgery in a porcine model. METHODS: We developed an accelerometer sensor that uses the piezoelectric effect to measure laryngeal twitching in three dimensions. This novel accelerometer sensor was placed in the anterior neck skin (transcutaneous) or postcricoid area. Stimulus thresholds, amplitude, and latency of laryngeal twitching measured using the accelerometer sensor were compared to those measured through EMG of the vocalis muscle. RESULTS: The amplitudes of the accelerometer sensor at the anterior neck and postcricoid area were significantly lower than those of EMG because of differences in the measurement method used to evaluate laryngeal movement. However, no significant differences in stimulus thresholds between the EMG endotracheal tube and transcutaneous or postcricoid accelerometer sensors were observed. CONCLUSION: Accelerometer sensors located at the anterior neck or postcricoid area were able to identify laryngeal twitching. The stimulus intensity measured with these sensors was equivalent to that from conventional vocalis EMG. Our novel IONM system with an accelerometer sensor that checks changes in surface acceleration can be an alternative to EMG of the vocalis muscle for IONM in the future.

Development of a Novel Intraoperative Neuromonitoring System Using a Surface Pressure Sensor to Detect Muscle Movement: A Rabbit Model Study

OBJECTIVES: False-negative or false-positive responses in intraoperative neuromonitoring (IONM) using electromyography (EMG) in thyroid surgery pose a challenge. Therefore, we developed a novel IONM system that uses a surface pressure sensor instead of EMG to detect muscle twitching. This study aimed to investigate the feasibility and safety of a new IONM system using a piezo-electric surface pressure sensor in an experimental animal model. METHODS: We developed the surface pressure sensor by modifying a commercial piezo-electric sensor. We evaluated the stimulus thresholds to detect muscle movement, as well as the amplitude and latency of the EMG and surface pressure sensor in six sciatic nerves of three rabbits, according to the stimulus intensity. RESULTS: The surface pressure sensor detected the muscle movements in response to a 0.1 mA stimulation of all six sciatic nerves. There were no differences in the thresholds of stimulus intensity between the surface pressure sensor and EMG recordings to detect muscle movements. CONCLUSION: It is possible to measure the change in surface pressure by using a piezo-electric surface pressure sensor instead of EMG to detect muscle movement induced by nerve stimulation. The application of IONM using a piezo-electric surface pressure sensor during surgery is noninvasive, safe, and feasible. Measuring muscle twitching to identify the state of the nerves using the novel IONM system can be an alternative to recording of EMG responses.

Effect of intraoperative neuromonitoring on efficacy and safety using sugammadex in thyroid surgery: randomized clinical trial

PURPOSE: The use of nondepolarizing neuromuscular blocking agents (NMBAs) may affect intraoperative neuromonitoring (IONM) during anesthesia used during thyroid and parathyroid surgery. METHODS: The use of sugammadex was evaluated in a prospective clinical study during thyroid surgery. Between July 2018 and January 2019, 129 patients were prospectively randomized to either the sugammadex group (group B) or the control group (group A). Group A patients underwent standardized IONM during thyroidectomy, while group B patients used an NMBA-reversal protocol comprised of rocuronium (0.6 mg/kg) in anesthesia induction and sugammadex (2 mg/kg) after first vagal stimulation (V0). A peripheral nerve stimulator was used to monitor the neuromuscular transmission. RESULTS: In our clinical study, it took 26.07 ± 3.26 and 50.0 ± 8.46 minutes to reach 100% recovery of laryngeal electromyography at injection of the sugammadex group (2 mg/kg) and the control group, respectively (P 0.9 within 4 minutes after administering 2 mg/kg of sugammadex at the beginning of resection. Surgery time was significantly shorter in group B than in group A (P < 0.001). Transient recurrent laryngeal nerve (RLN) paralysis was detected in 4 patients from group A and in 3 patients from group B (P = 0.681). There was no permanent RLN paralysis in the 2 groups. CONCLUSION: Our clinical study showed that sugammadex effectively and rapidly improved the inhibition of neuromuscular function induced by rocuronium. The implementation of the nondepolarizing neuromuscular block recovery protocol may lead to tracheal intubation as well as favorable conditions for IONM in thyroid surgery.

Prevalence of the right nonrecurrent inferior laryngeal nerve in a series of 100 total thyroidectomies / Prevalencia del nervio laríngeo inferior derecho no recurrente en una serie de 100 tiroidectomías totales

SUMMARY: The right nonrecurrent inferior laryngeal nerve (NRILN) is a rare occurrence generally associated with an aberrant right subclavian artery. Its prevalence ranges from 0.3 to 1.8 %. It is found mainly in thyroid surgeries, the most frequently performed cervical surgeries. This neural anomaly is almost never diagnosed preoperatively. Dysphagia may be a warning symptom, sometimes being incorrectly related to esophageal compression due to a goiter or thyroid cancer. The postoperative diagnosis of an accompanying aberrant right subclavian artery should be done to confirm the clinical picture and inform the patient of any possible future medical/ surgical procedures. The aim of this work is to determine the prevalence of the NRILN in patients undergoing total thyroidectomy in two reference centers for head and neck surgery in Paraguay. Prospective cross-sectional study in a series of 100 consecutive total thyroidectomies in the INCAN and the ORL Service in the Hospital Central of the IPS. 100 patients underwent a total thyroidectomy, 90 of whom were women. The average age was 47 years. 6 % also underwent a neck dissection for thyroid cancer. The preoperative diagnosis was multinodular goiter (MNG) in 84 cases and thyroid cancer in the remaining 16 (16 %). In one man aged 47 years (1 %) operated on for MNG and presenting slight to solid dysphagia, there was difficulty finding the right NRILN. It was located at the level of the lower edge of the inferior pharyngeal constrictor and its downward anomalous course was proven. Postoperatively, after confirmation of the diagnosis that the thyroid pathology was benign, a color echo-Doppler and a CT angiography corroborated the diagnosis of an associated aberrant right subclavian artery. Given the difficulty in locating the recurrent inferior laryngeal nerve in thyroid surgery, it is advisable to consider the possibility that it may be nonrecurrent and should be looked for at the level of its entrance to the larynx below the inferior constrictor. In such cases it is recommended that the patient be examined postoperatively to rule out an associated vascular anomaly. A tomography study of each patient with a thyroid pathology and dysphagia could contribute to the diagnosis of the vascular anomaly and maximize precautions in the nerve dissection, including use of a neurostimulator. The NRILN is a rare entity. In this case study, it represents 1 % of the patients operated on for thyroid pathology in the INCAN and IPS in a 1-year period (July 2016 - June 2017).

RESUMEN: El nervio laríngeo inferior no recurrente (NLINR) del lado derecho es una entidad rara asociada generalmente a una arteria lusoria. Su prevalencia oscila entre el 0,3 al 1,8 %. Su hallazgo se da sobre todo en cirugías tiroideas, al ser éstas las cirugías cervicales más frecuentemente realizadas. El diagnóstico preoperatorio de esta anomalía nerviosa es realizado en contadas ocasiones. La disfagia puede ser un síntoma de alerta ante esta situación, siendo a veces erróneamente relacionada con la compresión esofágica por un bocio o cáncer tiroideo. El diagnóstico postoperatorio de arteria lusoria acompañante debería realizarse para certificar el cuadro e informar al paciente ante eventuales procedimientos médico-quirúrgicos futuros. El objetivo de este trabajo consisitó en determinar la prevalencia del nervio laríngeo inferior no recurrente en los pacientes operados de tiroidectomía total en dos centros de referencia en cirugía de cabeza y cuello del Paraguay.Estudio prospectivo de corte transversal en una serie de 100 tiroidectomías totales consecutivas, operados en el INCAN y el Servicio de ORL del Hospital Central del IPS. Fueron sometidos a tiroidectomía total 100 pacientes, de los cuales 90 fueron del sexo femenino. La edad promedio fue de 47años. En 6% se realizó además vaciamiento cervical por cáncer de tiroides. El diagnóstico preoperatorio fue bocio multinodular (BMN) en 84 casos y cáncer de tiroides en los restantes 16 (16%). En un varón de 47 años, (1%) operado por bocio multinodular, y que refería disfagia leve a sólidos, se tuvo dificultad para encontrar al nervio laríngeo inferior derecho. Siendo el mismo localizado a nivel del margen inferir del constrictor inferior de la faringe y comprobándose su trayecto anómalo descendente. En el postoperatorio, una vez confirmado el diagnóstico de benignidad de la patlogía tiroidea, se realizó un ecodoppler color y una angiotomografía que corroboraron el diagnóstico de arteria lusoria asociada. Ante la dificultad en localizar al nervio laríngeo inferior recurrente en una cirugía tiroidea, es conveniente considerar la posibilidad de que el mismo sea no recurrente e ir a buscarlo a nivel de su ingreso a la laringe por debajo del constrictor inferior. En estos casos conviene estudiar al paciente en el postoperatorio para descartar una anomalía vascular asociada. El estudio tomográfico en todo paciente portador de patología tirroidea y disfagia podría contribuir al diagnóstico de la anomalía vascular y extremar los recaudos en la disección del nervio, incluso utilizando el neuroestimulador. El NLINR es una entidad rara. En esta casuística representa el 1 % de los pacientes operados por patología tiroidea en el INCAN e IPS en el periodo de 1 año (julio 2016/ junio 2017).

Ganglion cardiacum or juxtaductal body of human fetuses / 대한해부학회지

The ganglion cardiacum or juxtaductal body is situated along the left recurrent laryngeal nerve in the aortic window and is an extremely large component of the cardiac nerve plexus. This study was performed to describe the morphologies of the ganglion cardiacum or juxtaductal body in human fetuses and to compare characteristics with intracardiac ganglion. Ganglia were immunostained in specimens from five fetuses of gestational age 12–16 weeks and seven fetuses of gestational age 28–34 weeks. Many ganglion cells in the ganglia were positive for tyrosine hydroxylase (TH; sympathetic nerve marker) and chromogranin A, while a few neurons were positive for neuronal nitric oxide synthase (NOS; parasympathetic nerve marker) or calretinin. Another ganglion at the base of the ascending aorta carried almost the same neuronal populations, whereas a ganglion along the left common cardinal vein contained neurons positive for chromogranin A and NOS but no or few TH-positive neurons, suggesting a site-dependent difference in composite neurons. Mixtures of sympathetic and parasympathetic neurons within a single ganglion are consistent with the morphology of the cranial base and pelvic ganglia. Most of the intracardiac neurons are likely to have a non-adrenergic non-cholinergic phenotype, whereas fewer neurons have a dual cholinergic/noradrenergic phenotype. However, there was no evidence showing that chromogranin A- and/or calretinin-positive cardiac neurons corresponded to these specific phenotypes. The present study suggested that the ganglion cardiacum was composed of a mixture of sympathetic and parasympathetic neurons, which were characterized the site-dependent differences in and near the heart.

Safety of medial dissection of the thyroid gland along the trachea based on anatomic constancy of the laryngeal entry point of the recurrent laryngeal nerve

PURPOSE: The purpose of this study was to determine the extent of safety of medial dissection of the thyroid gland along the trachea. Medial to lateral dissection of the thyroid gland along the trachea after early division of the isthmus has been known to be a useful technique in thyroid surgery, especially for difficult cases, but the risk of injury of the recurrent laryngeal nerve (RLN) has constrained thyroid surgeons from utilizing this technique to its full extent. METHODS: Distances of the laryngeal entry point (LEP) of 134 RLNs of 71 patients from the midline of the trachea, and some other anatomical distances, were measured intraoperatively. The relationships of the intraoperatively measured data with circumferences of the cartilaginous portion of the trachea (CCT) around LEP measured preoperatively by CT scan were evaluated. RESULTS: LEP was always located within 2 mm vertically from the horizontally extended line of the inferior border of the cricoid cartilage and was the closest point from the midline in the whole course of the RLN. The distance between LEP and the midline was very closely correlated with CCT measured on preoperative CT scan, and it can be accurately calculated with a regression equation; Distance between LEP and the midline = (0.42 × CCT) + (1.2 × sex) + 3.2 (mm) (sex: female=0, male=1; R2 = 0.85). CONCLUSION: Early division of the isthmus and dissecting the thyroid off the trachea to the calculated extent is a safe and effective procedure.

Comparing the safety of harmonic ACE and ACE+ around the recurrent laryngeal nerve in swine models

PURPOSE: Among the various energy-based devices, ultrasonic shears are popular in thyroid surgeries. In this study, we tested the safety of Harmonic ACE and Harmonic ACE+ around the recurrent laryngeal nerve (RLN) in experimental swine models. METHODS: Harmonic ACE and Harmonic ACE+ were each tested in 4 piglets. Harmonic ACE and Harmonic ACE+ were activated at a 0- to 5-mm distance from the RLN. The function of the RLN was assessed using continuous electrophysiological monitoring. RESULTS: For Harmonic ACE, there was no adverse EMG event found when activated at 4- and 5-mm distances from the RLN. At a 2- to 3-mm distance, there were 4 adverse EMG events observed. In these 4 cases, adjacent tissue shrinkage occurred after 6 to 15 seconds of activation, and the RLN touched the Harmonic ACE. At a 1-mm distance, there were 2 adverse EMG events found after 25 seconds of activation. For Harmonic ACE+, there was no adverse EMG event observed when activated at 1- and 3-mm distances from the RLN. At a 0-mm distance, 2 adverse EMG events occurred after 6 to 10 seconds of activation. CONCLUSION: The safe distance of Harmonic ACE and ACE+ was 4 and 1 mm, respectively, in the swine models. Harmonic ACE+ is safer than Harmonic ACE because it did not cause any tissue shrinkage. Surgeons need to understand the characteristics of devices for safe operation.

The efficacy and safety of high-intensity focused ultrasound ablation of benign thyroid nodules

High-intensity focused ultrasound (HIFU) is a promising form of thermal ablation of benign thyroid nodules, but evidence supporting its use is scarce. The present review evaluated the efficacy and safety of single-session HIFU treatment of benign thyroid nodules. As reported in the literature, the extent of nodule shrinkage following treatment ranged from 48.8% to 68.8%. Like other forms of ablation, the shrinkage rate was greatest in the first 3-6 months, and the best responders were patients with small (≤10 mL) nodules. Complications were uncommon, but temporary vocal cord palsy occurred in 3%-4% of patients, and was related to the distance between the HIFU beam and the recurrent laryngeal nerve. Despite being safe and efficacious, a larger-scale prospective trial is required.

Técnica de Horsley para la reconstrucción del nervio laríngeo / Reconstruction of the laryngeal nerve by yhe Horsley technique

Introducción. La temida complicación de la tiroidectomía es la parálisis de las cuerdas vocales secundaria a lesiones del nervio laríngeo recurrente. En este estudio se analiza una técnica de reconstrucción para estas lesiones neurales. Objetivo. Describir los resultados funcionales de la reconstrucción inmediata de las lesiones del nervio laríngeo recurrente con la técnica de Horsley. Material y métodos. Se llevó a cabo un estudio prospectivo entre enero del 2000 y diciembre del 2015, en pacientes con sección del nervio laríngeo recurrente y reconstrucción de Horsley, en el cual se evalúan: a) los índices del análisis acústico de voz [tiempo máximo de fonación, perturbación involuntaria de la frecuencia (jitter), perturbación de la amplitud (shimmer) y frecuencia fundamental], b) los hallazgos estroboscópicos, y c) el índice de discapacidad vocal. El análisis estadístico se hizo con la prueba exacta de Fisher y con el programa SPSS™. Resultados. Se practicaron 1.547 tiroidectomías y se produjeron 10 secciones del nervio laríngeo recurrente (0,64 %): dos (0,12 %) inadvertidas (p=0,0001) y 8 (0,51 %) advertidas por infiltración tumoral. En los exámenes de la calidad de voz, se encontraron: frecuencias fundamentales bajas con medias de 104,79 ± 0,29 Hz en hombres (valor de referencia, VR=141,74) y de 208,12 ± 22,72 Hz en mujeres (VR=241,08), que se correlaciona con un jitter de 1,39 ± 0,99 % (VR=1,04); y también, disminución del tiempo máximo de fonación (media=10,9 ± 3,07 s). El índice de percepción de calidad de la voz fue de discapacidad leve de la voz (22,7 ± 11,8). La estroboscopia mostró cierre completo de la glotis en nueve pacientes (90 %) (p=0,005), con una posición adecuada de los cartílagos aritenoides, en siete. Conclusiones. La tasa de lesión inadvertida del nervio laríngeo recurrente en el Hospital Militar Central es de 0,12 %. La técnica de Horsley tiene unos resultados funcionales satisfactorios en el 90 % de los casos

Background. The most feared complication of thyroidectomy is the vocal cord palsy secondary to injury of the recurrent laryngeal nerve. In this study we analize the Horsley technique for reconstruction for this surgical injury. Objective. The aim of this study was to describe the functional outcomes of the reconstruction of the recurrent laryngeal nerve by the Horsley technique. Materials and methods. A prospective study including patients with section of the recurrent laryngeal nerve and the use of the of the Horsley technique for reconstruction was carried out in the period January 2000 to December 2015. The outcomes evaluated were: a) acoustic voice analysis indexes (maximum phonation time, involuntary disturbance of frequency (jitter), disturbance of amplitude (shimmer), and fundamental frequency); b) stroboscopic findings; and c) vocal disability index. The Fisher's exact test and the SPSS™ program were used for the statistical analysis. Results.The study included 1,547 thyroidectomies with 10 complete sections of the recurrent laringeal nerve (0.64%), 2 unnoticed injuries (0.12%) (p=0,0001), and 8 injuries identified intraoperatively in patients with tumor infiltration. In the voice quality test we found: low fundamental frequencies with median values of 104.79 ± 0, Hz in the male population (reference value, RV=141,74) and 208,12 ± 22,72 Hz in the female population (RV=241,08), wich correlates with a jitter of 1,39 ± 0,99% (RV=1,04) and with a decrease in maximum phonation time (median=10,9 ±3,07s). Index of perception of voice quality was mild voice disability (22,7 ± 11,8). Stroboscopy showed complete clossure of glottis in 9 patients (90%) (p=0,005), with an adequate position of the arytenoid cartilages in 7 patients. Conclusions. The rate of unnoticed injuries of recurrent laringeal nerve at Central Military Hospital in Bogotá, Colombia, is 0.12%. The Horsley reconstruction technique demonstrated satisfactory functional results in 90% of cases

Comparison between lignocaine nebulization and airway nerve block for awake fiberoptic bronchoscopy-guided nasotracheal intubation: a single-blind randomized prospective study / 대한마취과학회지

BACKGROUND: The preferred management strategy for difficult airways is awake fiberoptic bronchoscopy-guided intubation, which requires effective airway anesthesia to ensure patient comfort and acceptance. This randomized single-blind prospective study was conducted to compare lignocaine nebulization and airway nerve block for airway anesthesia prior to awake fiberoptic bronchoscopy-guided intubation. METHODS: Sixty adult patients scheduled for surgical procedures under general anesthesia were randomly allocated to two groups. Group N received jet nebulization (10 ml of 4% lignocaine) and Group B received bilateral superior laryngeal and transtracheal recurrent laryngeal nerve blocks (each with 2 ml of 2% lignocaine) followed by fiberoptic bronchoscopy-guided nasotracheal intubation. All patients received procedural sedation with dexmedetomidine. The intubation time, intubating conditions, vocal cord position, cough severity, and degree of patient satisfaction were recorded. Student’s t test was used to analyze parametric data, while the Mann-Whitney U test was applied to non-parametric data and Fisher’s test to categorical data. P values < 0.05 were considered statistically significant. RESULTS: The time taken for intubation was significantly shorter in Group B [115.2 (14.7) s compared with Group N [214.0 (22.2) s] (P = 0.029). The intubating conditions and degree of patient comfort were better in Group B compared with Group N. Although all patients were successfully intubated, patient satisfaction was higher in Group B. CONCLUSIONS: Airway nerve blocks are preferable to lignocaine nebulization as they provide superior-quality airway anesthesia. However, nebulization may be a suitable alternative when a nerve block is not feasible.

Fonoresultados en paciente con reconstrucción inmediata del nervio laríngeo recurrente durante cirugía de tiroides / Vocal outcome after immediate reconstruction of the recurrent laryngeal nerve in thyroid surgery

Objetivo: Evaluar la función fonatoria de pacientes con reconstrucción inmediata del Nervio Laríngeo Recurrente durante cirugía de tiroides. Materiales y Métodos: Se incluyeron 10 pacientes con sección unilateral del Nervio Laríngeo Recurrente con reconstrucción inmediata durante cirugía de tiroides, por anastomosis directa. Se analizaron los registros video-estroboscópicos, índice de Discapacidad Vocal y análisis acústico de la voz post-operatorios. Diseño:Resultados: Seguimiento de 24,2 ±17.3 meses. Análisis acústico de la voz, con prolongación del Jitter (1.39 ± 0.99 DE) y un tiempo máximo fonatorio disminuido de 10.9 ± 3.07 segundos. Cierre glótico completo en el 90% de los casos. El valor promedio del Índice de Discapacidad Vocal fue leve (22.7 ± 11.8 DE). Conclusión: Los resultados anatómicos y funcionales demuestran que esta técnica quirúrgica preserva la función fonatoria y la soportan como manejo primario de este tipo de lesiones correlacionándose con resultados ya descritos en la literatura.

Objective: Assess the phonatory function of patients with immediate reconstruction of the recurrent laryngeal nerve during thyroid surgery. Materials and Methods: 10 patients with unilateral recurrent laryngeal nerve section, with immediate reconstruction performed during thyroid surgery by direct anastomosis. Postoperative stroboscopy records, Voice Handicap Index and acoustic voice analysis were recollected. Design: Results: Follow-up 24,2 ±17.3 months. Acoustic voice analysis, with prolonged Jitter (1.39 ± 0.99 DE) and maximum phonation time decreased of 10.9 ± 3.07 seconds. Complete glottal closure in 90% of cases. The average value of Voice Handicap Index was mild (22.7 ± 11.8 DE). Conclusion: Anatomical and functional results demonstrates immediate reinnervation preserves the phonatory function, and supports it, as a primary management of this type of injury, in correlation with results already described in the literature.