Non-recurrent Laryngeal Nerve Research Articles

Non-Recurrent Laryngeal Nerve (NRLN) is a rare anatomical anomaly of the RLN

A 34-year young lady with a right-sided euthyroid nodule of 3 x 5 cm size for one year visited our clinic for surgery. FNAC was reported as colloid goiter. The right hemi- thyroidectomy surgery was planned. Intraoperatively while dissecting the right thyroid lobe, we could not find the right recurrent laryngeal nerve in its normal course, but we found a cord white-like structure running transversely & entering the larynx at the level of the cricothyroid muscle. We dissected it till its origin from the right vagus nerve in the neck. So, this was Non-Recurrent Laryngeal Nerve (NRLN) which is a rare anatomical anomaly of the Recurrent Laryngeal Nerve (RLN) which arises higher in the neck and runs a

Abu Dhabi Neural Mapping (ADNM) during Minimally Invasive Thyroidectomy Enables the Early Identification of Non-Recurrent Laryngeal Nerve and Prevents Voice Dysfunction.

The aim of this study was to evaluate the diagnostic accuracy of a neuromonitoring protocol—the Abu Dhabi Neural Mapping protocol (ADNM)—using a new device, Nim-Vital™, during minimally invasive thyroidectomy in the early identification of non-recurrent laryngeal nerve (n-RLN) problems and the preservation of its function. Method: Patients with thyroid disorders that required thyroid resection, who were admitted to the Department of Surgery at Burjeel Hospital, Abu Dhabi, between January and July 2022, were included in the study. The data were extracted from a prospective database and were analyzed retrospectively. All nerves at risk were identified and exposed at seven precisely defined anatomical points, with strict adherence to the intraoperative technical steps of neuromonitoring. These were sequentially applied to the vagal nerve (VN), the superior laryngeal nerve (SLN), and the recurrent laryngeal nerve (RLN). In the next step after the creation of the skin-platysma flap, the strap muscle’s lateral border was moved from the medial limb of the sternocleidomastoid without using any electrical device and without any manipulation of the thyroid gland. The VN was exposed in the carotid sheath and then stimulated using a monopolar probe at a precisely defined point above the clavicle, using anatomical landmarks. Results: In total, 136 women with a mean age of 40 years (range 18–74) and 36 men with a mean age of 42 (range 21–66), demonstrating 270 nerves at risk, were included in the analysis. Indications for surgery were malignancy in 70 cases, toxic goiter/Graves in 23 cases, retrosternal goiter in 21, and symptomatic multinodular goiter in 64 cases. Of these, 100 patients received a total thyroidectomy, 46 received a right lobectomy, and 24 received a left lobectomy only. For a total thyroidectomy, the median skin-to-skin surgery duration was 52 min (range 24–104 min) and the median hospital stay was 2 days (range 1–4 days). In 4 cases (4/146; 2.74%) the pre-dissection stimulation of the vagal nerve (VN1) at the ADNM’s precisely defined point did not create any signal or proper EMG-curve that indicated the existence of the non-RLN. Proximal dissection of the right VN at a precisely defined point by the ADNM’s level of incisura of the larynx created a positive signal. The separation point of the right non-RLN from the VN was discovered in all four patients. The postoperative video-laryngoscopy confirmed bilateral mobile vocal cords in all cases. Conclusions: Following the ADNM protocol during thyroid surgery minimizes the risk of a non-laryngeal nerve injury and prevents voice dysfunction.

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

<p>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.</p>

A Case Report of Non-Recurrent Laryngeal Nerve

The non-recurrent laryngeal nerve is a rare neurological disorder associated with the underdeveloped subclavian artery. During thyroidectomy, this abnormal nerve can be inadvertently damaged, causing permanent vocal cord paralysis. However, preoperative diagnosis of the abnormal subclavian artery can predict the presence of non-relapsed laryngeal nerve. We report a case of right recurrent laryngeal nerve-related thyroid surgery that was not noticed preoperatively on a CT scan of the neck but was accidentally encountered during thyroidectomy. Preoperative CT scan showed an abnormal right subclavian artery in the posterior esophagus, but was unnoticed. A female patient underwent total thyroidectomy with central compartment node autopsy for thyroid cancer. The recurrent laryngeal nerve on the left side was identified, as well as the non-relapsed laryngeal nerve on the right side. Postoperatively, the patient had normal vocal cord function. By identifying the abnormal right recurrent laryngeal nerve with a CT scan of the neck, it is possible to predict the right recurrent laryngeal nerve preoperatively, which may help prevent vocal cord paralysis.

An atypical bilateral trifurcation of recurrent laryngeal nerve

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

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: Anatomic and Embryologic Considerations, Imaging Findings, and Intraoperative Testing

The Nonrecurrent Laryngeal Nerve: Anatomic and Embryologic Considerations, Imaging Findings, and Intraoperative Testing

Surgical video on the successful preservation of the non-recurrent laryngeal nerve and the importance of preoperative CT imaging during total thyroidectomy: case report

Surgical video on the successful preservation of the non-recurrent laryngeal nerve and the importance of preoperative CT imaging during total thyroidectomy: case report

Left Nonrecurrent Laryngeal Nerve with Situs Inversus Totalis.

The recurrent laryngeal nerve (RLN), a branch of the vagus nerve, supplies the motor and sensation function of the larynx. Generally, RLN detours around the right subclavian artery on the right side and the aortic arch on the left side. In a rare anatomical variant, called nonrecurrent laryngeal nerve (NRLN), the nerve takes an aberrant path rather than descending into the thorax as usual. First reported in 1823, NRLN is a rare anomaly arising almost exclusively on the right side, reported in 0.3–0.8% of people, and associated with vascular anomalies of embryonic aortic arch development. The atypical vascular pattern of aberrant subclavian artery (arteria lusoria) running behind the trachea and esophagus allows the vagus nerve to pass freely, which then directly branches out as NRLN at the level of the larynx. On the other hand, cases of left NRLN, only reported in 0.004% of people, are all accompanied by significant pathologies such as situs inversus totalis with opposite vascular pattern of left aberrant subclavian artery. This rare anatomical variation is clinically important, as NLRN is a major risk factor for iatrogenic injury during thyroidectomy, parathyroidectomy, and other invasive procedures in the head and neck region.

Anomalous branching of the aortic arch in a dog.

Anomalies in the subclavian and common carotid arteries can be of interest in cases of cranial mediastinal surgeries, as well as to diagnose the cause of oesophageal constrictions leading to clinical signs of dysphagia (dysphagia lusoria). The development and regression of the aortic arches are of key importance in understanding the origin of these type of vascular anomalies. This report describes the congenital anomalous aortic origin of the common carotid and the subclavian arteries in a 14-year-old dog and the plausible developmental pattern failure. Academic dissection revealed a common bicarotid trunk and bisubclavian trunk arising from the most cranial aspect of the aortic arch. Despite the abnormal origin, these vessels displayed a predominantly standard anatomical course. All the anticipated branches were identified and described. Cardiac abnormalities were also noted including right atrial dilation, coronary sinus enlargement, right and left valvular endocardiosis, a patent foramen ovale and marked concentric left ventricular hypertrophy with compensatoryleft atrial dilation. Additionally, the right recurrent laryngeal nerve demonstrated an aberrant course consistent with a 'non-recurrent laryngeal nerve' (non-RLN). Awareness of the anatomical variations of the aortic arch is important for surgical interventions of the cranial mediastinum as well as radiological interpretation. Although infrequent, the variants similar to the one described here have been reported in different species.

Cover Image

The cover image is based on the Education A novel method to reconstruct right recurrent laryngeal nerve by transforming into nonrecurrent laryngeal nerve: The end-to-free vagal laryngeal branch end anastomosis by Yu-Long Wang et al., https://doi.org/10.1002/hed.26942.

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.

Nonrecurrent laryngeal nerve-an anatomical deviation

<p>Thyroidectomy is one of the most dispute and discussed surgery. Identification of recurrent laryngeal nerve is the most important step in this surgery. Among postop complications of thyroidectomy, the commoner is haematoma, transient hypocalcaemia and hoarseness.<strong> </strong>We report a rare case of nonrecurrent laryngeal nerve in a 25-year-old male with swelling in the right thyroid lobe. A 25-year-old male presented to the ENT OPD with complaints of swelling in thyroid region for 6 months with no other symptoms. On examination there was a 2×3 cm size nodule in the right lobe of thyroid. Rest of ORL examination was normal. On ultrasonogram there was an enlarged right lobe of thyroid with a nodular goitre. Fine needle aspiration cytology showed colloid goitre. Patient was planned for right hemithyroidectomy. Right side type 1 nonrecurrent laryngeal nerve was identified at the level of superior pole of thyroid branching from vagus and entering the larynx at the level of cricothyroid joint was identified intraoperatively.<strong> </strong>In conclusion, nonrecurrent laryngeal nerve though a very rare anomaly forms a crucial anatomical structure in thyroid surgery and is prone to injury. It is one of the preventable complications during thyroid surgery leading to postop vocal cord palsy. An in-depth anatomical knowledge and diligent surgical technique will help in identification and preservation of nonrecurrent laryngeal nerve.</p>

Неповоротний гортанний нерв, обумовлений аномальним ходом правої підключичної артерії (arteria lusoria), у пацієнтки з рецидивуючим папілярним тиреоїдним раком: перший в Україні документований клінічний випадок

Актуальність. Аберантна права підключична артерія (аrteria lusoria, AL) є рідкісною судинною аномалією дуги аорти в людини, що спостерігається з частотою 0,1–2,5 % та має важливе клінічне значення через поєднану аномалію ходу нижнього гортанного нерва (неповоротний гортанний нерв, НГН), імовірність пошкодження якого в тиреоїдній хірургії різко зростає. Уперше в Україні детально описаний клінічний випадок передопераційної діагностики AL, інтраопераційної ідентифікації НГН та проаналізований сучасний стан розробки питання. Мета: на прикладі історії пролікованої пацієнтки з папілярним тиреоїдним раком та аналізу світової літератури показати важливість дослідження анатомії дуги аорти з імовірним утворенням AL, що, у свою чергу, викликає ембріональне аномальне формування НГН із високим ризиком його пошкодження при операціях на щитоподібній залозі. Матеріали та методи. Наведений випадок рецидивуючого папілярного раку щитоподібної залози в молодої жінки, яка була двічі оперована (тотальна тиреоїдектомія з лівобічною радикальною дисекцією шиї, правобічна латеральна та центральна редисекція шиї), перед другою операцією при комп’ютерній томографії виявлена аномалія правої підключичної артерії. Запідозрена наявність правобічного НГН, що було підтверджено під час операції за допомогою електрофізіологічного нейромоніторингу. Аналіз відповідної світової літератури засвідчив актуальність питання, відсутність вітчизняних аналогів. Результати. На підставі отриманих при комп’ютерній томографії (із 3D-реконструкцією великих судинних структур шиї) зображень було встановлене аберантне відгалуження правої підключичної артерії від дистальної частини дуги аорти— AL. Було припущене існування нервової аномалії— НГН праворуч. Шляхом застосування електронейромоніторингу та дисекції правого блукаючого нерва під час операції судинно-нервова аномалія була підтверджена, що дозволило уникнути хірургічних ускладнень у вигляді порушення функції гортані, успішно провести хірургічне лікування шийних метастазів тиреоїдного раку. Висновки. Плануючи операції на щитоподібній залозі, слід мати на увазі можливість існування судинної аномалії дуги аорти з відповідним ризиком пошкодження нижнього гортанного нерва, що має неповоротний хід. Рентгенологічне або сонографічне обстеження може виявити аберантне розташування правої підключичної артерії, а застосування електронейромоніторингу— знайти НГН для уникнення його пошкодження при операціях на шиї.

Prevention of non-recurrent laryngeal nerve injury in robotic thyroidectomy: imaging and technique.

The aim of this report was to summarize observations, evaluate the feasibility, provide detailed information concerning proper techniques, and address limitations for non-recurrent laryngeal nerve (NRLN) dissection and release during the robotic bilateral axillo-breast approach (BABA) for thyroidectomy. The BABA approach was used in two cases of thyroidectomy in the setting of NRLN. Preoperative CT imaging findings suggesting the aberrant anatomy are reviewed and technical planning, inclusive of intraoperative nerve monitoring, was employed. Intraoperative videos with narrative discussion of technique for safe dissection are provided, along with supplementary video of additional technical guidance. In both cases, the NRLNs were identified, dissected, and preserved. We dissected the proximal segment of each NRLN to its origin. We determined that the use of only the NRLN proximal to distal robotic dissection jeopardized the nerve. The BABA approach with the Type I NRLN is similar to the dissection of the recurrent laryngeal nerve (RLN) in transoral thyroidectomy. Due to interference with endoscopic viewing caused by the thyroid cartilage, the Type I NRLN is more challenging to manage both at the laryngeal entry point and its origin from the vagus nerve (VN). For the Type II NRLN, it is essential to identify its point of origin and the reflection of the nerve from the VN. Therefore, modification of nerve dissection to mirror open surgery with bidirectional nerve dissection assisted in avoidance of traction injury to the nerve. We presented a video, a detailed description of methods, and discussed limits for NRLN management in robotic BABA. This report included (i) a description of the aberrant anatomy and CT scans to inform surgeons of the possible NRLN locations, (ii) a description of a technique for using the nerve monitor in the robotic surgeries, and (iii) a description of the techniques used to isolate and protect the NRLN during the robotic surgery. In robotic BABA, our NRLN-sparing technique and degree included mainly a multi-directional nerve dissection (i.e., medial-grade, later-grade approach together with proximal to/from distal) using athermal technique. The NRLN-sparing technique is predominantly carried out in an anterior dissection plane.

Anatomical, Functional, and Dynamic Evidences Obtained by Intraoperative Neuromonitoring Improving the Standards of Thyroidectomy.

The use of intraoperative neuromonitoring (IONM) is getting more common in thyroidectomy. The data obtained by the usage of IONM regarding the laryngeal nerves’ anatomy and function have provided important contributions for improving the standards of the thyroidectomy. These evidences obtained through IONM increase the rate of detection and visual identification of recurrent laryngeal nerve (RLN) as well as the detection rate of extralaryngeal branches which are the most common anatomic variations of RLN. IONM helps early identification and preservation of the non-recurrent laryngeal nerve. Crucial knowledge has been acquired regarding the complex innervation pattern of the larynx. Extralaryngeal branches of the RLN may contribute to the motor innervation of the cricothyroid muscle (CTM). Anterior branch of the extralaryngeal branching RLN has always motor function and gives motor branches both to the abductor and adductor muscles. In addition, up to 18% of posterior branches may have adductor and/or abductor motor fibers. In 70–80% of cases, external branch of superior laryngeal nerve (EBSLN) provides motor innervation to the anterior 1/3 of the thyroarytenoid muscle which is the main adductor of the vocal cord through the human communicating nerve. Furthermore, approximately 1/3 of the cases, EBSLN may contribute to the innervation of posterior cricoarytenoid muscle which is the main abductor of ipsilateral vocal cord. RLN and/or EBSLN together with pharyngeal plexus usually contribute to the motor innervation of cricopharyngeal muscle that is the main component of upper esophageal sphincter. Traction trauma is the most common reason of RLN injuries and constitutes of 67–93% of cases. More than 50% of EBSLN injuries are caused by nerve transection. A specific point of injury on RLN can be detected in Type 1 (segmental) injury, however, Type 2 (global) injury is the loss of signal (LOS) throughout ipsilateral vagus-RLN axis and there is no electrophysiologically detectable point of injury. Vocal cord paralysis (VCP) develops in 70–80% of cases when LOS persists or incomplete recovery of signal occurs after waiting for 20 min. In case of complete recovery of signal, VCP is not expected. VCP is temporary in patients with incomplete recovery of signal and permanent VCP is not anticipated. Visual changes may be seen in only 15% of RLN injuries, on the other hand, IONM detects 100% of RLN injuries. IONM can prevent bilateral VCP. Continuous IONM (C-IONM) is a method in which functional integrity of vagus-RLN axis is evaluated in real time and C-IONM is superior to intermittent IONM (I-IONM). During upper pole dissection, IONM makes significant contributions to the visual and functional identification of EBSLN. Routine use of IONM may minimalize the risk of nerve injury. Reduction of amplitude more than 50% on CTM is related with poor voice outcome.

ЗАКОНОМЕРНОСТИ АНАТОМИИ И ТОПОГРАФИИ ГОРТАННЫХ НЕРВОВ У ВЗРОСЛОГО ЧЕЛОВЕКА ПО ДАННЫМ ЛИТЕРАТУРЫ

Establishing the morphological regularities of laryngeal nerves of the human is extremely important in surgical and oncological practice. During surgical intervenrions on the thyroid gland, damage of the superior and inferior laryngeal nerves can occur — the second most common complication after hypoparathyroidism. Based on the studied literature data on anatomy and topography of the laryngeal nerves in an adult, a number of the morphological features have been identified. The article describes the morphometric parameters of the laryngeal nerves and their branches. Also, the article describes variants of the localisation of the internal branch of the superior laryngeal nerve relatively to the superior laryngeal artery, a number of classifications based on the localisation of the external branch of the superior laryngeal nerve relatively to the superior thyroid artery and the inferior laryngeal constrictor, variants for the inferior laryngeal nerve passage in tracheoesophageal groove, its location in relation to the trunk and branches of the inferior thyroid artery, Berry's ligament, Zuckerkandl's tubercle and also such anatomical features of the inferior laryngeal nerve as its extralaryngeal branching and cases of non-recurrent laryngeal nerve. These topographic and anatomical features of the laryngeal nerves that should be taken into account for the identification of the nerves during surgery, and also allows them to be considered prerequisites for an increased risk of iatrogenic trauma.

English

Both the cases discussed here had right sided NRLN, out of which one had associated aberrant right subclavian artery. None had iatrogenic nerve palsy. Dissection was difficult as during the routine procedure of dissection, the nerve was not found in its usual route and was found that the right laryngeal nerve was not recurrent and originated directly from the vagus nerve. The non-recurrent laryngeal nerve (NRLN) is a rare embryologically derived variant of the recurrent laryngeal nerve and is found in 0.25 to 0.99% of patients who undergo thyroid surgery. On the right side, NRLN is found in 0.3% to 0.8% of patients and it is extremely rare on the left (0.004%).[1-2] The right NRLN is found to be associated with an aberrant right subclavian artery (86.7%) In experienced hands, meticulous dissection in the region of the tracheoesophageal groove will result in identification of RLN. In any case, if the nerve is not seen / found longitudinally along the tracheoesophageal groove, then dissecting transversely along the fascial spaces between the carotid sheath and the larynx, will allow identification of the presence of NRLN. Recurrent laryngeal nerve is a branch of the vagus nerve that is associated with both motor function and sensation of the larynx. It supplies all the intrinsic muscles of the larynx except the cricothyroid muscles. The non-recurrent laryngeal nerve (NRLN) is a rare embryologically derived variant of the recurrent laryngeal nerve and occurs in 0.25 to 0.99% of patients who undergo thyroid surgery and was first reported by Steadman in 1823.[3] on the right side, NRLN is found in 0.3% to 0.8% of patients and on the left side, it is extremely rare (0.004%).[1-2] The right NRLN is found to be associated with an aberrant right subclavian artery (86.7%).[1],[4] The NRLN is usually an unexpected surgical discovery, specifically during thyroidectomy. Hence, adequate anatomic knowledge of the normal course and variations/types of NRLN, and careful dissection during surgery is necessary to prevent iatrogenic injury to the nerve. We are reporting two cases of NRLN, which were identified while performing total thyroidectomy in patients diagnosed with papillary ca thyroid.

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.

Predictive value of ultrasound diagnosis of aberrant right subclavian artery with non-recurrent laryngeal nerve.

This study aims to evaluate the predictive value of color Doppler ultrasound for the diagnosis of aberrant right subclavian artery (ARSA) with a co-occurring non-recurrent right laryngeal nerve (NRLN). In the present study, 58 patients with ARSA (ARSA group) and 1,280 patients without ARSA (controls) were diagnosed by ultrasonography. In addition, 32 patients with ARSA (ARSA operation group) and controls underwent thyroidectomy with surgical exploration with or without NRLN. Then, the incidence of NRLN was analyzed. The right common carotid artery (RCCA) and right subclavian artery (RSA) trends were observed by ultrasound, and classified into two types: RCCA and RSA originating from the innominate artery (IA) (type I), and IA could not be detected (type II). A total of 32 cases of NRLN were found in the ARSA operation group, but no case was found in controls, and the difference was statistically significant (p = 0.0006). The difference in the constituent ratio of type I and type II was statistically significant between the ARSA group and controls (p = 0.0002). That is, the IA could not be detected in the ARSA group, which was accompanied by the RCCA that originated from the aortic arch, while the IA was detected in most patients in the control group at the level of the sternoclavicular joints. Aberrant right subclavian artery can be rapidly detected by ultrasonography. Aberrant right subclavian artery occurs when the RCCA originates from the aortic arch during detection. Patients with ARSA sometimes have co-occurring NRLN. Hence, vigilance in protecting the NRLN is needed during an operation.