Recurrent Nerve Research Articles

Evaluation of Intraoperative Neural Monitoring During Thoracoscopic Surgery for Esophageal Cancer.

Recurrent laryngeal nerve paralysis (RLNP) induces aspiration pneumonia and reduces the patient's quality of life. To decrease the incidence of RLNP, we performed intraoperative neural monitoring (IONM) during thoracoscopic surgery for esophageal cancer and evaluated its usefulness. A total of 737 consecutive patients who underwent thoracoscopic surgery for esophageal cancer were enrolled in this study. Between May 1995 and March 2016, thoracoscopic esophagectomies were performed using video-assisted thoracoscopic surgery (VATS) with a small incision, whereas from April to June 2023, we used positive pressure pneumothorax with port placement only [minimum invasive esophagectomy (MIE)]. A total of 110 consecutive patients who underwent thoracoscopic surgery with IONM (IONM group) were retrospectively compared with those who underwent VATS or MIE without IONM (No-IONM group). The incidence of RLNP [Clavien-Dindo (CD) classification of ≥1] on postoperative day (POD) 5 was 13.9% in the IONM group, which was significantly lower than that of the no-IONM group (31.2%, p<0.001). Even when comparing only patients who underwent MIE, the incidence of RLNP on POD5 was 13.9% in the IONM group, which was significantly lower than that in the no-IONM group (26.2%, p=0.035). The incidence of postoperative pneumonia (CD ≥2) was 10.9% in the IONM group, which was significantly lower than that in the no-IONM group (26.1%, p=0.005). Bilateral RLNP did not occur in any of the IONM groups. IONM is a useful tool for reducing RLNP incidence and postoperative pneumonia after thoracoscopic surgery for esophageal cancer.

ASO Author Reflections: Prognostic Factors for Recovery from Left Recurrent Laryngeal Nerve Palsy After Minimally Invasive McKeown Esophagectomy: A Retrospective Study.

ASO Author Reflections: Prognostic Factors for Recovery from Left Recurrent Laryngeal Nerve Palsy After Minimally Invasive McKeown Esophagectomy: A Retrospective Study.

Ortner’s Syndrome With Primary Pulmonary Hypertension - A Case Report

Ortner’s Syndrome or Cardio-vocal syndrome is a manifestation of hoarseness secondary to left recurrent laryngeal nerve (RLN) palsy with abnormal cardiovascular components. The association of pulmonary hypertension with Ortner’s Syndrome has not been widely available in the literature with very few cases reported worldwide.We present a case of a 17 years old lady with underlying Primary Pulmonary Hypertension, who presented with progressive hoarseness over the past 3 years associated with breathlessness and easy fatigue on exertion. Herein we discuss the options of treatment modality for Ortner’s Syndrome.

ASO Visual Abstract: Prognostic Factors for Recovery from Left Recurrent Laryngeal Nerve Palsy After Minimally Invasive McKeown Esophagectomy: A Retrospective Study.

ASO Visual Abstract: Prognostic Factors for Recovery from Left Recurrent Laryngeal Nerve Palsy After Minimally Invasive McKeown Esophagectomy: A Retrospective Study.

Vagus Nerve Stimulation in the Carotid Triangle: An Effective Method for Monitoring the Recurrent Laryngeal Nerve in Thyroid and Parathyroid Surgery.

Our objective is the description of the technique of vagus nerve stimulation in carotid triangle in order to monitor the recurrent laryngeal nerve (RLN) during thyroid and parathyroid surgery. We stimulated the vagus nerve in the carotid triangle during 150 thyroid or parathyroid surgeries using a monopolar electromyography electrode inserted under the mastoid process towards the jugular foramen as a cathode, and using another subdermal electrode in the mastoid as an anode. Another complementary method of vagus stimulation was achieved with a pair of subdermal electrodes, placing the cathode at the mandibular angle and the anode at the mastoid. In all patients, compound muscle action potential (CMAP) was recorded in the vocal cords with both stimulation techniques, allowing semi-continuous monitoring to be carried out. Intraoperative lesions were detected in 16 of the cases; 9 of them were transient with CMAP recovery achieved when modifying surgical maneuvers. Vagus nerve stimulation in the carotid triangle is a reliable technique for monitoring the RLN in thyroid surgery. Vagus nerve stimulation in the carotid triangle is effective and safe for RLN monitoring, and it is a clear alternative to direct continuous stimulation of the nerve that by contrast requires its dissection in the carotid sheath.

Thyroidectomy Outcomes in Obese Patients

IntroductionObese patients often have higher complication rates after elective general surgeries; however, few studies have examined the outcomes after thyroidectomy. This study examines whether increased body mass index (BMI) is associated with poor postoperative outcomes after thyroid surgery. MethodsA retrospective review of patients who underwent thyroidectomy from 2015 to 2018 was performed. Demographics, comorbidities, pathology, and extent of resection (total versus hemithyroidectomy) were examined. Patients were classified into BMI groups according to the WHO definitions, and the incidence of surgical outcomes was determined in each group. Surgical outcomes of interest included readmission rates (RRs), length of stay, average operating room time, return to the operating room, hypocalcemia, postop infections, hematomas, and recurrent laryngeal nerve injury. Between-subjects statistics including independent samples t-test, ANOVA, and chi-square analyses were performed. ResultsThere were n = 465 patients included with a mean BMI 32.35 (standard deviation = 8.55) and median BMI 30.78 (Q1 = 26.26, Q3 = 36.73). There were no differences between BMI groups in age, gender, smoking, heart disease. There was a positive association between increased BMI and postoperative infection (P < 0.001), pneumonia (P = 0.018), and surgical site infection (P = 0.04), which were highest for BMI > 40. Increased BMI was associated with a higher 30-d RR (P = 0.008), particularly for BMI >40 versus BMI <40 (6.2% versus 1.05%; P = 0.003). There were no significant differences between surgical outcomes for patients with increased BMI who underwent total thyroidectomy or hemithyroidectomy. ConclusionsExcellent postoperative outcomes were observed in all BMI categories. Higher postoperative infection and 30-d RRs were observed in the morbidly obese. Contrary to previous studies, operating room times were similar regardless of BMI.

Morphology of the inferior laryngeal nerve (recurrent nerve) in the anterior cervical region: A report of 30 thyroidectomies

Objective: To study the morphological peculiarities of the left and right Inferior Laryngeal Nerves (ILN) in the anterior cervical region and their variations induced by thyroid pathology. Materials and methods: The study concerned 30 patients who underwent thyroidectomy at the ENT and cervico-facial surgery department of Idrissa POUYE general hospital (HOGIP) from June 1st, 2018 to June 30, 2019. Age, sex, morphotype, operative indication, type of thyroidectomy, route, morphometry, and mode of termination of the ILN were studied. Results: The mean age was 42 years. There were 29 women and one man. Eleven patients (36.7%) were brevilinear, 8 patients (26.6%) were longilinear and 11 patients (36.7%) were of intermediate morphotype. Multinodular goiter was the indication for surgery in 18 cases. A total of 53 ILNs were studied (29 left and 24 right). Path variations concerned 8 left recurrent nerves (28%). The mean diameter of the ILN was 2mm. Longilinear patients and those with intermediate morphotypes had the longest recurrent nerves, while brevilinear patients had the thickest nerves. On the right, the ILN was bifid in 10 cases (41.6%), trifurcated in 3 cases (12.5%), and fan-shaped in 1 case (4.1%). On the left, it was bifid in 23 cases (79.3%) and trifurcated in 2 cases (6.8%). Conclusion: The caliber of the recurrent nerve is relatively large, and can sometimes be spindly, especially on the right. Morphotype may predict ILN dimensions. Extra-laryngeal division of the ILN is a common situation.

Refining postoperative monitoring of recurrent laryngeal nerve injury in esophagectomy patients through transcutaneous laryngeal ultrasonography.

Recurrent laryngeal nerve injury (RLNI) leading to vocal cord paralysis (VCP) is a significant complication following minimally invasive esophagectomy (MIE) with upper mediastinal lymphadenectomy. Transcutaneous laryngeal ultrasonography (TLUSG) has emerged as a non-invasive alternative to endoscopic examination for evaluating vocal cord function. Our study aimed to assess the diagnostic value of TLUSG in detecting RLNI by evaluating vocal cord movement after MIE. This retrospective study examined 96 patients with esophageal cancer who underwent MIE between January 2021 and December 2022, using both TLUSG and endoscopy. VCP was observed in 36 out of 96 patients (37.5%). The incidence of RLNI was significantly higher on the left side than the right (29.2% vs. 5.2%, P < 0.001). Postoperative TLUSG showed a sensitivity and specificity of 88.5% (31/35) and 86.5% (45/52), respectively, with an AUC of 0.869 (P < 0.001, 95% CI 0.787-0.952). The percentage agreement between TLUSG and endoscopy in assessing VCP was 87.4% (κ = 0.743). TLUSG is a highly effective screening tool for VCP, given its high sensitivity and specificity. This can potentially eliminate the need for unnecessary endoscopies in about 80% of patients who have undergone MIE.

An improved method and means with the function of automatic adjustment of electrical signal parameters for detection of the recurrent laryngeal nerve

The article presents the results of the development of software and hardware for identifying the recurrent laryngeal nerve (RLN). In the course of research, it was found that the effectiveness of detecting as result of stimulation of the RLN with a pulsed electric current depends on its frequency. On this basis, it is proposed to use software tools for automatically adjusting electrical signal parameters in order to stimulate the tissues of a surgical wound as efficiently as possible. In thyroid surgery, these tools are used to minimize the risk of damage to the RLN. An improved method for stimulating surgical wound tissue is presented. The main algorithms of the tools and the architecture of the software part are presented. The proposed device was tested on the basis of a medical centre in Ukraine.

A meta-analysis of total thyroidectomy and lobectomy outcomes in papillary thyroid microcarcinoma.

Current research on the most effective surgical method for papillary thyroid microcarcinoma is in dispute. Specifically, whether a total thyroidectomy (TT) is superior to a thyroid lobectomy (LT) in terms of recurrence rate, postoperative complications, and recurrence-free survival is an issue to be addressed. The objective of this study was to compare TT with LT in terms of recurrence, postoperative complications, and recurrence-free survival. In accordance with the Preferred Reporting Items for Systemic Reviews and Meta-Analyses standards, the PubMed, Embase, web of science and the Cochrane Library database were searched for relevant studies comparing TT versus LT. By pooling the relative risks (RR) of the 2 surgical procedures, perioperative results of the 2 group can be estimated. Recurrence-free survival was calculated from hazard ratios between the 2 surgical group. This meta-analysis included 8 studies involving 16,208 patients. In the TT group, there were fewer recurrences than in the LT group. (RR = 0.68; 95% confidence interval [CI], 0.39 to 1.18; P = .001). In subgroup analyses based on country and sample size, there were no significant differences between the 2 groups for the recurrence rates. We found that patients that underwent LT had lower total complication rates (RR = 15.12; 95% CI, 8.89 to 25.73; P = .009), wound recurrent laryngeal nerve injury and hypocalcemia. In terms of survival, TT can provide better recurrence-free survival than LT, with a hazard ratios of 0.57 (95% CI 0.36 to 0.90; P = .003). Comparing TT with LT, no statistical difference was found in recurrence rates between the 2 groups. In addition, the analysis showed a slight improvement in long-term recurrence-free survival for patients who underwent TT than for those who underwent LT, a finding with potential clinical implications for management decisions on papillary thyroid microcarcinoma treatment.

A Case of Unilateral Recurrent Nerve Palsy Improved by Chemotherapy for Esophageal Cancer

A Case of Unilateral Recurrent Nerve Palsy Improved by Chemotherapy for Esophageal Cancer

Intraoperative cricothyroid muscle electromyography may contribute to the monitorization of the external branch of the superior laryngeal nerve during thyroidectomy.

In thyroid surgery, both the recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN) should be preserved for maintaining the vocal cord functions. We aimed to evaluate whether EMG of the CTM applied after the superior pole dissection provided additional informative data to the IONM via ETT or not, regarding the EBSLN function. The prospectively collected data of the patients, who have undergone thyroidectomy with the use of IONM for the exploration of both the RLN and EBSLN between October 2016 and March 2017, were evaluated retrospectively. Patients over 18 years of age with primary thyroid surgery for malignant or benign thyroid disease, and whom were applied CTM EMG with a needle electrode after the completion of thyroidectomy were included in the study. In the study, each neck side was evaluated as a separate entity considering the EBSLN at risk. The data of 41 patients (32 female, 9 male) (mean age, 46.7+9.1; range, 22-71) were evaluated. Sixty seven EBSLNs out of 26 bilateral and 15 unilateral interventions were evaluated. With EBSLN stimulation after the superior pole dissection, positive glottic EMG waveforms via ETT were obtained in 45 (67.2%) out of 67, and the mean glottic amplitude value was 261+191 μV (min-max: 116-1086 μV). Positive EMG responses via the CTM EMG were achieved from all of the 67 EBSLNs (100%) with stimulation using a monopolar probe at the most cranial portion above the area of divided superior pole vessels. The mean value of CTM amplitudes via CTM EMG obtained with EBSLN stimulation was 5268+3916 μV (min-max:1215 -19726 μV). With EBSLN stimulation, the mean CTM EMG amplitude was detected significantly higher than the mean vocal cord amplitude (p<0.0001). The CTM EMG provided more objective quantifiable data regarding the EBSLN function (100% vs 67,2%, p<0.001). In addition to the IONM via ETT, intraoperative post-dissection CTM EMG via needle electrode is a safe, simple and applicable method that may provide significant additional informative data to IONM with ETT by obtaining and recording objective quantitative data related to the EBSLN function.

Hemithyroidectomy, does the indication influence the outcome?

PurposeHemithyroidectomies are mainly performed for two indications, either therapeutically to relieve compression symptoms or diagnostically for suspicious nodule(s). In case of the latter, one could consider the approach to be rather extensive since the majority of patients have no symptoms and will have benign disease. The aim of this study is to investigate the complication rates of diagnostic hemithyroidectomy and to compare it with the complication rates of compressive symptoms hemithyroidectomy.MethodsData from patients who had undergone hemithyroidectomy either for compression symptoms or for excluding malignancy were extracted from a well-established Scandinavian quality register (SQRTPA). The following complications were analyzed: bleedings, wound infections, and paresis of the recurrent laryngeal nerve (RLN). Risk factors for these complications were examined by univariable and multivariable logistic regression.ResultsA total of 9677 patients were included, 3871 (40%) underwent surgery to exclude malignancy and 5806 (60%) due to compression symptoms. In the multivariable analysis, the totally excised thyroid weight was an independent risk factor for bleeding. Permanent (6–12 months after the operation) RLN paresis were less common in the excluding malignancy group (p = 0.03).ConclusionA range of factors interfere and contribute to bleeding, wound infections, and RLN paresis after hemithyroidectomy. In this observational study based on a Scandinavian quality register, the indication “excluding malignancy” for hemithyroidectomy is associated with less permanent RLN paresis than the indication “compression symptoms.” Thus, patients undergoing diagnostic hemithyroidectomy can be reassured that this procedure is a safe surgical procedure and does not entail an unjustified risk.

Outcomes of Preoperative Medical Therapy for Thyroidectomy in Autoimmune Thyroid Disease

IntroductionThyroidectomy provides definitive treatment for autoimmune thyroid disease (AITD) often resulting in improved quality of life. Historically, patients with AITD undergoing thyroidectomy have increased rates of postoperative hypoparathyroidism and recurrent laryngeal nerve palsy. We investigated the outcomes of preoperative medications in patients with AITD undergoing thyroidectomy. MethodsWe performed a retrospective analysis of patients who underwent thyroidectomy for AITD at a single institution from 2015 to 2021. Surgical outcomes and perioperative laboratory values were analyzed by type of AITD and type of preoperative medical treatment: none, saturated solution of potassium iodide (SSKI), corticosteroids, or both SSKI and corticosteroids. ResultsA total of 123 patients underwent thyroidectomy for AITD and were included in analysis: 50 received no preoperative medications, 40 received SSKI, 20 received corticosteroids, and 13 received both. Seventy-six patients had Graves’ disease and 47 had Hashimoto’s thyroiditis. There were no significant differences in blood loss, operative time, wound complications, hematoma, or recurrent laryngeal nerve injury for patients treated with preoperative corticosteroids compared to those who were not. Patients who received corticosteroids and patients with Graves’ disease more commonly had at least one instance of hypocalcemia postoperatively (P < 0.01, P = 0.01), although only on postoperative day 1 was mean calcium < 8.5 mg/dL. There was no difference in rate of transient or permanent hypoparathyroidism. ConclusionsPatients who received corticosteroids preoperatively had no increased risk of complications. They did have mildly lower calcium levels in the early postoperative period, although no difference in hypoparathyroidism. Further exploration is warranted to investigate the impact of preoperative corticosteroids on operative difficulty, quality of life, and autoantibody clearance.

Case Series of Surgical Treatment in Pediatric Thyroid Carcinoma in a Single Institution.

The prevalence of thyroid carcinoma (TC) among pediatric and adolescent populations is infrequent, yet its global occurrence is escalating. Insufficient information pertaining to TC in the pediatric populace of Indonesia presents issues in the identification and management of patients with this condition. The objective of this study is to provide a detailed account of a collection of pediatric TC cases that were recorded at a tertiary care center throughout an extended interval of eight years. The present study conducted a retrospective data analysis of ten patients who received a diagnosis of TC during the period spanning from 2014 to 2022. The present study focused on analyzing the clinical manifestation, diagnostic measures, treatment modalities, and immediate postoperative consequences of TC. All patients diagnosed with thyroid cancer exhibited the presence of neck lump. Nine patients underwent total thyroidectomy, while one patient underwent isthmolobectomy. The histopathologic evaluation confirmed the diagnosis of thyroid cancer in every individual. There were a significant number of patients, up to 50%, who encountered complications after undergoing surgery. Two patients reported the hoarseness of voice, whereas two other patients experienced the signs of hypocalcemia. Only one patient exhibited both these symptoms simultaneously. The implementation of total thyroidectomy as a surgical intervention in pediatric patients poses a notable challenge. Postoperative monitoring for potential complications following surgery for total thyroidectomy is imperative. The current study provides evidence that the utilization of total thyroidectomy in combination with lymph node dissection as indicated in patients with lymph node metastases in pediatric patients with thyroid carcinoma leads to a significant reduction in the probability of recurrence of lymph node enlargement. During the performance of surgical procedures, meticulous observation plays a key role in mitigating the risk of postoperative complications, such as hypoparathyroidism, hypocalcemia, and injury to the recurrent laryngeal nerve. Thus, it is imperative to conduct follow-up procedures for post-surgical interventions among pediatric patients diagnosed with TC.

Anatomical relations of the recurrent laryngeal nerve in thyroid dissection

Introduction: Recurrent laryngeal nerve (RLN) palsy is one of the major complications thyroidectomy. Visualization of the anatomical relations of the RLN with branches of the inferior thyroid artery (ITA) remains essential for preservation of RLNs. Suspensory ligament of Berry, inferior horn of the thyroid cartilage is considered as other important landmarks for safe thyroidectomy. The objective of this study was to describe the various anatomical relations of the RLN during thyroid dissection.Methods: An observation cadaveric study was conducted by simple random sampling of 35 cadavers with a total of 70 RLNs over a one-year period, from June 2022 to June 2023. The cadavers that had thyroidotomies and goitres were excluded from the study.Results: The majority of RLNs in this series had a retrovascular course (with respect to the ITA or its branches): 57% on the right and 68.6% on the left. The course of 64/70 of the dissected nerves was posteromedial to the suspensory ligament of Berry, while the other 6 nerves passed between the fibres of this ligament. All RLNs penetrated the larynx by passing posteriorly to the inferior horn of the thyroid cartilage on both sides. No case of non-recurrent laryngeal nerve was observed.Conclusion: This preliminary study illustrates the numerous anatomical variants of the RLN with respect to the ITA and its branches. The RLN mainly has a retrovascular course on both the right and the left sides.

Routine use or selective use of the Intraoperative neuromonitoring during thyroidectomy

Intraoperative neuromonitoring (IONM) has become a widely utilized technique in thyroid surgery, While the routine identification of the recurrent laryngeal nerve has improved the safety of thyroidectomy, recurrent laryngeal nerve palsy remains an important complication. Some studies have shown promising results with IONM, demonstrating a lower incidence of nerve palsy compared to traditional visualization. However, the overall impact of IONM remains debated, as not all studies confirm its efficacy, especially in redo thyroid surgery. The use of IONM offers benefits in identifying and preserving the external branch of the superior laryngeal nerve, especially in cases of multinodular goiters. The decision to employ IONM should be individualized based on the surgeon's experience and the patient's clinical situation. However, its routine use is not universally supported, and its advantages may be more pronounced in specific high-risk patients and low volume surgeons.

갑상선 수술에서 피부 전극을 이용한 신경모니터링의 실제적인 적용

Preservation of the recurrent laryngeal nerve during thyroid surgery is crucial for preserving the patient's quality of life after surgery. It is still considered standard procedure to visually identify the recurrent laryngeal nerve and carefully dissect it in order to preserve the nerve. However, due to the numerous advantages of neuromonitoring, its application in thyroid surgery is gradually increasing. Despite the advantages of neuromonitoring, electromyography tubes could not be used in most thyroid surgeries because they were not covered by insurance. Recently, there has been active research conducted on neuromonitoring using needle electrodes or skin electrodes as alternatives to electromyography (EMG) tubes. In this review, we will examine the practical clinical application of recent neuromonitoring techniques that utilize skin electrodes.

갑상선 수술중 신경모니터링의 최근 연구

Thyroid surgery is associated with a risk of injury to the recurrent laryngeal nerve(RLN), the external branch of the superior laryngeal nerve(EBSLN), and voice changes. Intraoperative neuromonitoring(IONM) has already gained universal reliability to help in nerve identification, safe nerve dissection, and prediction of postoperative vocal cord function. IONM techniques have evolved over the past decade into intermittent IONM(I-IONM) and continuous IONM(C-IONM) modes of application. Research in the field of IONM continues, exploring new techniques and approaches to further enhance the safety and efficacy of thyroid surgery. In this article, the role of IONM and its recent studies will be reviewed.

원격접근방식의 로봇 및 내시경 갑상선 절제술시 신경 감시술

Vocal fold paralysis is a dangerous complication of thyroid surgery that is often fatal. Therefore, intraoperative neuromonitoring (IONM) has recently been widely adopted and used in thyroid surgery. IONM is thought to be more helpful in identifying the recurrent laryngeal nerve (RLN) and predicting its function in a limited surgical space than conventional thyroid surgery, but there are few reports on this. Therefore, we would like to discuss IONM during robotic or endoscopic thyroidectomy.