Non-recurrent Inferior Laryngeal Nerve Research Articles

Non-recurrent Laryngeal Nerve During Intraoperative Neuromonitoring Thyroidectomy: A Case Report and Literature Review.

Complete and precise knowledge of the neck anatomy and its eventual anomalies is crucial while performing a safe thyroid and parathyroid surgery. Embryo-genetic malformations of the IV branchial arch can lead to an uncommon anatomical alteration known as non-recurrent inferior laryngeal nerve. Its prevalence varies between 0.7% for the dextral branch and 0.04% for the sinistral. In these cases, the inferior laryngeal nerve branches originate directly from the cervical vagus nerve, entering the larynx without hooking, on the right side around the subclavian artery or on the left around the aortic arch. The presence of a non-recurrent laryngeal nerve is challenging, due to the increased risks of iatrogenic damage to the nerve, which results in hoarseness, dysphagia, glottal obstruction, vocal cords palsy, and serious airway impairment. We present the case of a 58-year-old woman. The patient was admitted to our department for a nodule classified as Bethesda IV in the right thyroid lobe. Through the use of intraoperative neuromonitoring (IONM), surgeons detected intraoperatively a non-recurrent laryngeal nerve. A subsequent computed tomography scan confirmed an anomalous right subclavian artery branching from the left aortic arch, the Lusoria Artery. Anatomical variants represent pitfalls in this case and an accurate knowledge of the neck region is imperative while performing thyroid surgery. Devices such as IONM are useful for detecting abnormalities that may lead to iatrogenic damages.

Electrophysiological monitoring of the nonrecurrent inferior laryngeal nerve and radiological evaluation of concurrent vascular anomalies.

The objective of this study was to characterize the electrophysiological characteristics of nonrecurrent inferior laryngeal nerves (NRILNs) that were dissected via intraoperative neuromonitoring (IONM) and concomitant vascular anomalies in patients with NRILNs. A retrospective analysis was conducted on 7865 patients who underwent thyroidectomy with IONM at three tertiary referral centers. The study included 42 patients in whom an NRILN was detected. IONM data and postoperative vocal cord (VC) examinations were recorded for all patients. The absence of an initial vagal EMG response and/or a short (<3.5 ms) latency period during the initial vagal stimulation or the inability to identify the RLN within the Beahrs triangle was considered highly suspicious for the presence of an NRILN. Postoperative cross-sectional imaging was performed in 36 out of 42 patients to assess any concurrent vascular anomalies. The prevalence of NRILN was 0.53%. An NRILN was suspected due to EMG findings in 32 (76%) patients and the inability to identify the RLN within the Beahrs triangle in the remaining 10 (24%) patients. The mean right VN latency period was 3.05 ± 0.15 ms. The V1 latency period of the right VN was shorter than 3.5 ms in 39 (93%) and longer than 3.5 ms in 3 (7%) patients. One of these three patients with latency>3.5ms had a large mediastinal goiter. Transient VC paralysis occurred in one (2.4%) patient. Of the 36 patients with postoperative imaging data, 33 (91.4%) had vascular anomalies. All 33 patients had aberrant right subclavian arteries, and 13 (39.4%) also had accompanying additional vascular anomalies. The NRILN is an anatomical variation that increases the risk of nerve injury. Observation of an absent EMG response and/or a short latency period during the initial vagal stimulation facilitates the detection of an NRILN at an early stage of thyroidectomy in the majority of patients.

The Presence of an Arteria Lusoria Should Be Checked When Reporting 18 F-FCH PET/CT Performed to Localize Hyperfunctioning Parathyroid Glands.

Nonrecurrent inferior laryngeal nerve (NRILN) is a rare anatomical variant, which significantly increases the risk of nerve injury during neck surgery, for example, thyroidectomy or parathyroidectomy (PTX). The absence of the brachiocephalic trunk and presence of arteria lusoria (AL) are strong predictors of NRILN in the right neck. FCH PET/CT is now a recognized imaging modality in hyperparathyroidism (HPT). We report 2 patients with primary or renal HPT in whom FCH PET detected right HFPTs and low-dose noncontrast CT evidenced AL. The NRILN was thus preserved during PTX. We recommend searching for AL on FCH PET/CT (even low-dose) in HPT before PTX.

内視鏡補助下甲状腺手術中に神経モニタリングで非反回下喉頭神経を診断し得た1例

Thyroidectomy by video assisted neck surgery (VANS) is associated with an elevated risk of recurrent laryngeal nerve injury, especially in the presence of unexpected anatomical abnormalities, such as non-recurrent inferior laryngeal nerve (NRILN), which can be exceedingly difficult to identify and preserve. To reduce the risk of nerve damage, computed tomography (CT) and ultrasonography are useful for preoperative diagnosis, but the number of cases in which anatomical abnormalities can be diagnosed by these modalities is limited. At our department, intraoperative neuromonitoring is performed during all thyroid surgeries, including VANS, in an attempt to reduce the risk of nerve injury.

Usefulness of intraoperative nerve monitoring for giant type AB thymoma combined with an aberrant right subclavian artery: a case report

Abnormal tumor vascularization and escalating tumor size represent two major impediments that make cancer surgery impossible or complicated. Herein, we report the case of a giant thymoma (type AB) in a 58-year-old woman who presented with cough and yellow sputum. The thymoma grew extensively from the neck to the upper mediastinum. The patient exhibited an aberrant right subclavian artery and a non-recurrent inferior laryngeal nerve. Intraoperative nerve monitoring facilitated the identification and preservation of vital nerves spanning the neck and chest, including the non-recurrent inferior laryngeal nerve. Furthermore, the tumor was divided naturally along the constriction, and a good field of view was acquired to identify abnormal right subclavian arteries and nerves that ran deep in the tumor and surgical field. The tumor was safely removed without complications using intraoperative nerve monitoring, and the thymoma that grew extensively from the neck to the upper mediastinum and was associated with an aberrant right subclavian artery was resected. Intraoperative nerve monitoring was helpful in identifying the non-recurrent inferior laryngeal nerve and left recurrent laryngeal nerve.

Intra-operative discovery of nonrecurrent inferior laryngeal nerve: a report of 3 cases including one of left nonrecurrent inferior laryngeal nerve and literature review

&lt;p&gt;The nonrecurrent inferior laryngeal nerve (NRILN), a rare variant in the course of the inferior laryngeal nerve, passes transversely into larynx directly arising from the vagus nerve that increases the risk of damage to the nerve during thyroid and parathyroid surgery. We discussed clinical significance of non-recurrent laryngeal nerve during cervicotomy. Its importance was demonstrated in three clinical cases as well as the related literature reviews. All patients underwent bilateral thyroidectomy for a multinodular goiter. Two patients had identification of the NRILN on the right side. The third patient had the NRILN on the left side. The diagnosis of this anatomical variation was made per-operatively on all cases. The NRILN is an exceptional anomaly but overlooking its risk may lead to grave morbidity. This is a supplementary proof in favour of systematic dissection of the recurrent inferior laryngeal nerve (RILN) during all thyroid and parathyroid surgery.&lt;/p&gt;

Semi-prone thoracoscopic esophagectomy for esophageal carcinoma with aberrant right subclavian artery and non-recurrent inferior laryngeal nerve

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

The Nonrecurrent Laryngeal Nerve Without Abnormal Subclavian Artery: Report of Two Cases and Review of the Literature.

As a variant of recurrent inferior laryngeal nerve (RILN), the nonrecurrent inferior laryngeal nerve (NRILN) is closely related to the occurrence of abnormal subclavian artery (ASA). The nonrecurrent inferior laryngeal nerve has been found in patients without arterial abnormalities, which is seen in the coexistence of NRILN and RILN, but it is easily confused with sympathetic-inferior laryngeal anastomosis branch (SILAB). We encountered 2 right NRILN patients without ASA during thyroid surgery. This article summarizes the characteristics of these cases and proposes methods to distinguish the coexistence of NRILN and RILN from SILAB. So far, 11 articles have reported 16 cases of NRILN without arterial abnormalities. In patients without artery abnormality, the vagus nerve could send out a descending branch NRILN at the bifurcation of the carotid artery and enter the larynx after anastomosis with RILN. Adequate dissection of the carotid sheath may avoid confusion with SILAB, and neural monitoring is also expected to provide a reference for the identification.

Nadir görülen bir olgu: nonrekürren laringeal sinir

Non-recurrent inferior laryngeal nerve (NRLN) is a very rare nerve variation seen during thyroidectomy. Identification and preservation of this nerve is crucial for post-operative life of the patient. In this paper, we presented a 55-year old female patient with right NRLN identified during operation performed due to multinodular goiter (MNG). This presented case was intraoperatively identified as NRLN during right lobe dissection and it was preserved through its course until entrance to the larynx with careful dissection. Patient was discharged at first postoperative day without problem during postoperative monitoring. Anatomic variations may cause nerve damage; therefore identification and preservation with careful dissection have utmost importance.

Non-recurrent inferior laryngeal nerve: a case report

The incidence of Non-recurrent laryngeal nerve (NRLN) is reported to be 0.6%-0.8% on the right side and in 0.004% on the left side. Damage to this nerve during thyroidectomy may lead to vocal cord complications and should therefore be prevented. A middle-aged woman with a nodular goiter who underwent subtotal thyroidectomy for multinodular colloid goiter. We encountered a non-recurrent laryngeal nerve on the right side in a patient during surgery. We were not able to find the inferior laryngeal nerve in its usual position using the customary anatomical landmarks. Instead, it was emerging directly from the right vagus nerve at a right angle and entering the larynx as a unique non-bifurcating nerve. Nonrecurrent inferior laryngeal nerve incidence is very rare, but when present, increases the risk of damage during thyroidectomy. Hence, it is very important to be aware of the anatomical variations of the inguinal lymph node (ILN) and the use of safe meticulous dissection while looking for the nerve during thyroidectomy. The use of Intra-operative neuro-monitoring (IONM) if available in thyroid surgery allows the surgeon to recognize and differentiate branches of the inferior laryngeal nerve (ILN) from sympathetic anastomoses, as well as NRLN during surgery.

Intraoperative finding non-recurrent inferior laryngeal nerve, critical step of thyroid surgery, literature review, and case report

Intraoperative finding non-recurrent inferior laryngeal nerve, critical step of thyroid surgery, literature review, and case report

A rare clinical case of a concurrence of multiple endocrine neoplasia type 2A (Sipple’s syndrome) with the arteria lusoria involving atopy of the non-recurrent right inferior laryngeal nerve

A rare clinical case of a concurrence of multiple endocrine neoplasia type 2A (Sipple’s syndrome) with the arteria lusoria involving atopy of the non-recurrent right inferior laryngeal nerve

Four cases of non-recurrent inferior laryngeal nerve during thyroid and parathyroid surgery

Four cases of non-recurrent inferior laryngeal nerve during thyroid and parathyroid surgery

Anatomical variation in the right non-recurrent laryngeal nerve reported from studies using pre-operative arterial imaging.

The right non-recurrent (inferior) laryngeal nerve (NRLN) is a rare anatomical variant associated with an arterial anomaly, the aberrant right subclavian artery (ARSA), that is detectable by pre-operative imaging (POI) using computed tomography and/or ultrasound. Most surgical studies have utilized two major types, NRLNs arising near the upper pole of the thyroid gland (type 1), vs. at a lower level (type 2) but with two subtypes defined by relationships to the inferior thyroid artery (ITA). This review found 8 English language surgical studies using POI that reported at least 1 NRLN and had anatomical information; of the 88 right NRLNs, 69.3% were classified as type 2 and 30.7% as type 1. Meta-analysis yielded a weighted proportion of 74.0% for type 2, but with substantial heterogeneity. For a subgroup of 5 POI studies with information on subtypes, 22 (59.5%) of 37 type 2 nerves were type 2a (i.e., running at or above the ITA). Similarly, a separate review of large surgical series without POI found that 60.4% of all 91 type 2 NRLNs were type 2a. The study findings should be relevant to the increasing numbers of anterior neck surgeries including bilateral thyroidectomies. A need was identified for studies on inter-observer reliability (agreement) among surgeons on NRLN types, and on injury rates (and related symptoms) by the type of NRLN.

Peripheral Nerve Anatomy Revisited: Modern Requirements for Neuroimaging and Microsurgery.

Detailed anatomic investigation of peripheral nerve topography underlies the correct application of intraoperative neuromonitoring (IONM) and ultrasonography, both well-established methods to prevent nerve palsy during surgical operations and to elucidate pathomechanisms in disease. In this study, we analyzed the anatomy of selected peripheral nerves in the head and neck regions to improve the outcome of endocrine and migraine surgeries. Anatomic dissections of 204 hemilarynges were performed to study the topography of the inferior laryngeal nerve (ILN). Measurements were taken from the lower rim of the cricoid and from the Zuckerkandl tubercle to the beginning of the furcation of the ILN. For the analysis of peripheral nerves contributing to migraine pathogenesis, 22 hemifaces were investigated by dissection and ultrasonography. The supratrochlear and supraorbital nerves and their relationship to the corrugator supercilii muscle are described. For identification of the ILN, the cricoid offers a suitable intraoperative landmark. A single branch existed in 5% of specimens on the left side and in 3% on the right side. Bifurcation was present in 72.5% and 62% and trifurcation in 18% and 29% of cases, respectively. IONM signals from the vagus nerve were positive if derived proximal to and negative if derived distal to the branching off of a nonrecurrent ILN (nrILN). By ultrasonographic identification of a brachiocephalic trunk, an nrILN could be excluded. For migraine surgery, possible compression points of the supratrochlear and supraorbital nerves were identified, and a workflow algorithm for ultrasound visualization of these nerves is provided. Anat Rec, 302:1325-1332, 2019. © 2019 Wiley Periodicals, Inc.

A case of thyroid cancer with a non-recurrent inferior laryngeal nerve which preoperatively left vocal cord is paralyzed

A case of thyroid cancer with a non-recurrent inferior laryngeal nerve which preoperatively left vocal cord is paralyzed

Nonrecurrent laryngeal nerve: A rare clinical presentation in thyroid surgery- A report of 2 cases

Surgical damage to the inferior laryngeal nerve is one of the most feared complications of thyroid surgery. A detailed knowledge of anatomical variations is necessary. Nonrecurrent inferior laryngeal nerve is a rare anomaly on the right side and is exceptional on the left. The typical course of the inferior laryngeal nerve is due to the embryological development of the aortic arch and supra-aortic vessels, and nonrecurrence is associated with a vascular anomaly such as a right retroesophageal subclavian artery. The nervous anomaly on the left side is possible only with the occurrence of cardiac dextroposition (situs inversus) and a left retroesophageal subclavian artery. The situation is more dangerous when a nonrecurrent branch of the inferior laryngeal nerve is associated with a recurrent branch. This anomaly does not appear to be associated with a vascular anomaly in all cases. We came across two cases of NRLN after performing 965 thyroid surgeries.

A functional assessment of anatomical variants of the recurrent laryngeal nerve during thyroidectomies using neuromonitoring

PurposeThe aim of the study was to assess the usefulness of intraoperative neuromonitoring (IONM) in identifying anatomical variants of the recurrent laryngeal nerve (RLN) during thyroidectomies, with emphasis on the nerve’s relationship to the inferior thyroid artery (ITA), Zuckerkandl’s tubercle, nonrecurrent laryngeal nerves (NRLNs), and extralaryngeal bifurcation.MethodsA total of 128 subjects undergoing surgery for thyroid disorders were enrolled in the study, and the course and anatomical variants of RLN were assessed with IONM application.ResultsThe standard relationship between RLN and ITA was that the artery and nerve intersect (100%). The right RLN was below the ITA in 76.67% of the patients, and the left RNL was below it in 75.81%. There were no statistically significant differences in the relationship between RLN and ITA on the two sides; and gender did not significantly influence the relationship between the RLN and ITA on either side. In one patient a nonrecurrent inferior laryngeal nerve was present on the right side (0.83%). RLN bifurcation was observed in 33.33% of the patients on the right and in 19.35% on the left side; the difference between sides was statistically significant (p < 0.05). Posterior tubercle (Zuckerkandl’s tubercle) was observed on the right in 83% of the subjects and on the left in 69%. The age, thyroid volume and body mass index (BMI) did not influence the size of the tumor.ConclusionsThe utilization of IONM of the RLN in thyroid surgery adds a new dimension to the standard of visual nerve identification allowing for functional nerve testing at the most vulnerable area of the dissection: at the level of Berry’s ligament, posterior tubercle (Zuckerkandl’s tubercle) and crossing of the RLN with the inferior thyroid artery.

Successful video-assisted thoracoscopic surgery in prone position in patients with esophageal cancer and aberrant right subclavian artery: report of three cases

BackgroundAn aberrant right subclavian artery (ARSA) with an associated nonrecurrent right inferior laryngeal nerve (NRILN) is a relatively rare anomaly that occurs at a frequency of 0.3 to 2.0% of the general population. NRILN has been mainly documented in the head and neck region; it has been rarely described in patients with esophageal cancer, especially those undergoing thoracoscopic surgery. Video-assisted thoracoscopic surgery for esophageal cancer (VATS-E) is becoming more widespread as a reliable minimally invasive surgical procedure associated with reduced perioperative complications.Case presentationHerein, we report three cases of esophageal cancer with ARSA and NRILN which underwent successful VATS-E. Case 1, a 53-year-old male who had early stage esophageal cancer was performed VATS-E. Upper gastrointestinal (GI) series showed “Bayonet sign” (T1aN0M0, pStageIA in UICC). Case 2, a 75-year-old male who had advanced esophageal cancer was performed neoadjuvant chemotherapy and following VATS-E. This case had right thoracic duct and “Bayonet sign” on upper GI series (T1bN2M0, pStage IIIA in UICC). Case3, a 72-year-old male who had advanced esophageal cancer was performed neoadjuvant chemotherapy and following VATS-E (T3N2M0, pStageIIIB in UICC). All of these three cases were performed VATS-E and discharged without any complication.ConclusionVATS-E in the prone position is a feasible procedure that can reduce the risk of complications with an enlarged and clear view, and knowledge of this type of anomaly is very important for surgeons who perform esophagectomy.

Clinical anatomy and features non-recurrent inferior laryngeal nerve in thyroid surgery. Case report

В последние десятилетия отмечается значительный успех в хирургии щитовидной железы, однако частота развития пареза гортани вследствие повреждения возвратного гортанного нерва остается высокой. Детальное изучение разных вариантов топики нерва – одно из направлений, дающих возможность снизить его травматизацию. Невозвратный нижний гортанный нерв является редкой анатомической особенностью, которая выявляется при операциях на щитовидной железе в 0,3–1% случаев. Несмотря на такую редкую встречаемость, к сожалению, атипичное расположение невозвратного гортанного нерва создает предпосылки для его ятрогенного повреждения. В статье проведен анализ литературы, описаны причины возникновения, связь с аномалией магистральных сосудов и клиническое значение. Описаны два случая выявления невозвратного нижнего гортанного нерва в хирургической клинике ФГБУ РНЦРР МЗ РФ.