Non-recurrent Laryngeal Nerve Research Articles

A Phylogenetic and Ontogenetic Perspective of the Unique Accumulation of Arterial Variations in One Human Anatomic Specimen.

Background and objectives: Anatomical dissection is an indispensable means of acquiring knowledge about the variability of the human body. We detected the co-existence of several arterial variations within one female anatomic specimen during routine anatomical dissection. The aim of this study was to evaluate if this status is a regular pattern in any of other vertebrates. Materials and Methods: Besides of a meticulous anatomic dissection, we performed a literature review concerning the frequency, the phylogenesis, and ontogenesis of all of these variations. Results: Exceptionally, the middle colic artery arose from an extraordinarily divided celiac trunk. The kidneys received three polar arteries. On the left side, a corona mortis replaced the obturator artery. The aortic arch gave rise to a bicarotid trunk, and the right subclavian artery originated and coursed as a typical lusorial artery leading to a non-recurrent laryngeal nerve on the right side. Furthermore, variations of the branches of the thyrocervical trunk were found to be present. Extraordinarily, in their cervical portion both internal carotid arteries gave rise to two arteries each. All of these variations developed within two to three weeks, around the sixth week of gestation. It was not possible to ascribe all or even one of the variations to a singular species of vertebrates. Conclusion: Apparently, arterial variations are frequently a result of random development. Medical professionals must always be aware of anatomical variations; the absence of such awareness would create major difficulties during surgery. The present case confirms the relevance of anatomical dissection, particularly for medical students.

Nonrecurrent Laryngeal Nerve: A Case Report and Literature Review

We report the case of a patient submitted to a right hemithyroidectomy for a follicular adenoma, when we found a nonrecurrent laryngeal nerve. This is a really rare anatomical presentation that can seriously compromise the integrity and preservation of the inferior laryngeal nerve during thyroid surgery. We describe how we found and managed this anatomical variant and we conduct a review of the most recent Literature about nonrecurrent laryngeal nerve.

Nonrecurrent Laryngeal Nerve: A Case Report and Literature Review

We report the case of a patient submitted to a right hemithyroidectomy for a follicular adenoma, when we found a nonrecurrent laryngeal nerve. This is a really rare anatomical presentation that can seriously compromise the integrity and preservation of the inferior laryngeal nerve during thyroid surgery. We describe how we found and managed this anatomical variant and we conduct a review of the most recent Literature about nonrecurrent laryngeal nerve.

Anatomical Variations in Recurrent Laryngeal Nerves in Thyroid Surgery.

To study terminal bifurcation of recurrent laryngeal nerves (RLNs) with original direction to larynx entry and to decrease the risk of vocal cord paralysis in thyroid patients. The RLNs of 294 patients (482 sides) were dissected according to the branches into the larynx, and the original direction of each RLN trunk in thyroid surgery was recorded. (1) About 30.9% of the RLNs gave off multiple branches into the larynx. (2) Two and 3 branches of RLNs into the larynx were found in 25.5% and 5.4% of the cases, respectively. (3) In 0.4% or 2 cases, the RLN trunk combined with the inferior branch of the vagus nerve. (4) Nonrecurrent laryngeal nerve appeared in 2 cases. (5) On the left side, 68.0%, 25.6%, and 6.4% of cases were found with 1, 2, and 3 bifurcations of RLN to larynx entry, respectively. On the right side, 69.8%, 25.8%, and 4.4% cases were identified with 1, 2, and 3 bifurcations of RLN to larynx entry, respectively. (6) The combining dissection approach was proved as successful and safe for protecting the RLN with no permanent RLN paresis. Because of the anatomical variation in RLNs with extralaryngeal bifurcation, it is necessary to increase the awareness of surgeons about these variations so as to protect bifurcated nerves in thyroid surgery.

Utility of intraoperative neuromonitoring in detecting recurrent nerve's anatomical anomalies during thyroidectomy.

Anatomical variations such as a non-recurrent laryngeal nerve (NRLN) are very rare (reported rates within 0.6-1% to the right side and only four cases to the left side) but they can lead to serious risk of nerve lesion during thyroidectomy. It is known that to prevent inferior laryngeal nerve lesions, it is mandatory to obtain a correct and wide exposure of the nerve during all kind of thyroid surgeries but in case of laryngeal nerve position anomalies, it is hard to achieve a safe nerve identification. Continuous intraoperative neuromonitoring (C-IONM) technology can detect the presence of NRLN. In this study we present seven cases of NRLN incidentally found during our last 10-year experience, in a total of 1074 procedures, including total thyroidectomy and lobectomy. Three out of seven cases were identified with the help of C-IONM. On the other hand, the other four cases of non-recurrent laryngeal nerve were identified during an extensive dissection of the thyroid lodge. We registered no nerve palsy in the group of patients who underwent surgery with the help of C-IONM, while we had two nerve palsies (out of four cases) in the group of patients without the help of C-IONM. In our experience we also registered a reduction of surgery time when we used the C-IONM. In our opinion C-IONM is a safe method to discover anatomical anomalies such as a non-recurrent laryngeal nerve and may help to reduce nerve palsy rate.

Intra-operative vagal neuromonitoring predicts non-recurrent laryngeal nerves: technical notes and review of the recent literature

Background During thyroid surgery, extreme caution must be taken not to harm the recurrent laryngeal nerve to avoid vocal cord palsy. A non-recurrent laryngeal nerve (NRLN) is a rare anatomical variation that is extremely vulnerable during thyroid surgery. Methods Description of two NRLN during thyroid surgery discovered early by using continuous intra-operative vagal nerve neuromonitoring and review of the literature. Results During thyroid surgery, we use continuous intra-operative vagal nerve neuromonitoring starting with checking vagal nerve signals. It is essential to start stimulation in the most proximal portion of the carotid sheath. An absent pre-dissection signal on the right vagal nerve with a positive signal on the left vagal nerve indicates a non-recurrent course of the right laryngeal nerve. Post-operatively computed tomography scan (CT-scan) was performed and showed an associated extra-anatomical course of the subclavian artery also known as an arteria lusoria. Conclusion The NRLN is an important surgical challenge because unilateral palsy can lead to permanent hoarseness. This anomaly emphasizes the importance of a thorough surgical dissection and the use of intra-operative vagal nerve neuromonitoring. Our method of continuous intra-operative vagal nerve monitoring makes it possible to predict a non-recurrent laryngeal nerve in an early stage during surgery.

Possibilities of preoperative ultrasound of neck vessels in the diagnosis of non-recurrent laryngeal nerve

Background: According to the anatomical data, the non-recurrent laryngeal nerve is a rather common abnormality and can be found in 4.78% of people. At the same time, the non-recurrent laryngeal nerve is difficult to visualize during surgery, which increases the risk of its damage.
 Aim: to determine the possibilities of ultrasound of neck vessels in the preoperative diagnosis of the aberrant right subclavian artery (arteria lusoria) and the abnormality of the branches of the vagus nerve.
 Materials and methods: An observational, single-center, single-stage, randomized, uncontrolled clinical trial was performed, which included patients in whom surgery was performed due to thyroid and parathyroid pathology. In the preoperative period, all patients underwent the ultrasound of the right half of the neck vessels and the mediastinum with visualization of the brachiocephalic trunk and its branches. When the brachiocephalic trunk was detected in the preoperative period, mobilization of the thyroid gland during operation was started with ligation of the upper pole vessels, and followed by a search for the recurrent laryngeal nerve. However, if the brachiocephalic trunk was absent, the right common carotid artery was traced as low as possible to the aortic arch and assessed on its relationship with the right subclavian artery. In such cases, thyroid mobilization was started from the lateral surface of the lobe with the necessary visualization of all structures of this region and followed by a primary search for the inferior laryngeal nerve. When the non-recurrent laryngeal nerve was detected, the computed tomography of the brachiocephalic arteries was performed in the postoperative period.
 Results: The study has shown that 202 (95.28%) patients out of the total 212 revealed the brachiocephalic trunk on preoperative ultrasound and the recurrent laryngeal nerve was located in a the typical place. Arteria lusoria was detected in 4 (1.89%) cases after the preoperative ultrasound. In this group of patients the non-recurrent laryngeal nerve was identified during operation and the aberrant right subclavian artery was confirmed at computed tomography. In 6 (2.83%) cases the brachiocephalic trunk could not be detected on ultrasound due to the constitutional features of the patient. However, in all these cases, the typical recurrent laryngeal nerve was identified during a surgery.
 Conclusions: The ultrasound of the neck vessels is the effective method to detect arteria lusoria, which is the predictor of the non-recurrent 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

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

Case of dysphagia lusoria in a patient with a non-recurrent laryngeal nerve.

Case of dysphagia lusoria in a patient with a non-recurrent laryngeal nerve.

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.

Incidental presence of non recurrent laryngeal nerve in our series of thyroidectomy

<p class="abstract"><strong>Background:</strong> Recurrent laryngeal nerve (RLN) injury is one of the most important and preventable complications of thyroidectomy which is the cause of post-operative iatrogenic vocal cord paralysis. The non-recurrent laryngeal nerve (NRLN), which is found in 0.25–0.99 of the patients who undergo thyroid surgery, is a rare embryologically-derived variant of the recurrent laryngeal nerve (RLN). Identification and prevention of injury to the laryngeal nerve is very important in thyroid surgery. The objective of the study was to highlight the incidence of Non-recurrent laryngeal nerve in our series of thyroidectomy cases.</p><p class="abstract"><strong>Methods:</strong> In the Department of Otorhinolaryngology, Pondicherry a retrospective analysis of all the thyroid surgeries that were operated between August 2006-November 2018 for various indications on a total of 1006 patients was done with specific interest in the lookout for anatomical variant of recurrent laryngeal nerve and findings were recorded. </p><p class="abstract"><strong>Results:</strong> Among all the cases, two patients with MNG who had underwent Total thyroidectomy were found to have anatomical variants of recurrent laryngeal nerve (non recurrent laryngeal nerve) intra operatively.</p><p class="abstract"><strong>Conclusions:</strong> The NRLN is a rare finding and is associated to an increased risk in iatrogenic injury especially during thyroid surgeries unless thorough anatomical knowledge and cautious dissection is not done.</p><p> </p>

Nonrecurrent laryngeal nerve in thyroid surgery: Frequency, anatomical variations according to a new classification and surgery consideration.

The nonrecurrent laryngeal nerve (NRLN) is a rare embryologically derived variant of the RLN. We aimed to identify the proportion of NRLN (during thyroidectomy), classify clinical NRLN types, and recommend some surgical considerations. In this prospective study, from May 2017 to September 2018, our hospital carried out 2158 thyroid operations. We reported the NRLN rate and distinguished NRLN into four types. Overall, NRLN had an incidence rate of 0.74% (16 out of 2158 total thyroid surgeries). We did not detect any patient with left-sided NRLN. The traveling patterns of the nerves could be classified as descending (12.5%), vertical (25%), ascending (37.5%), or V-shaped (25%). The NRLN is a rare variation of the RLN. From our experience, we recommend the guidelines will help surgeons to avoid NRLN injury.

WITHDRAWN: Non-recurrent laryngeal nerve in thyroid surgery: Frequency, anatomical variations according to a new classification and surgery consideration

WITHDRAWN: Non-recurrent laryngeal nerve in thyroid surgery: Frequency, anatomical variations according to a new classification and surgery consideration

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.

Anatomical Variations of Recurrent Laryngeal Nerve: The Danger in Thyroid Surgery

Objectives: We report two types of anatomical variations of the recurrent laryngeal nerve in two patients. Through these two patients we wanted to highlight our surgical approach of the recurrent nerve in an unusual position and to describe the surgical implication of these almost rare variations. Case report: patient aged 28 and 58 admitted for goiter. They underwent a right lobisthmectomy. Both recurrences were approached retrograde. The anatomical variations of the nerve concerned the non-recurrent laryngeal nerve in the first patient. In the second patient there were three anatomical variations, namely an extra laryngeal bifurcation of the nerve, a pre-vascular position of the nerve and a branch connecting the vagus nerve and the recurrent nerve. No recurrence nerve injury was noted. Conclusion: The anatomical variations of the nerve are numerous. A careful dissection is a guarantee of a good prognosis.

Non-Recurrent Laryngeal Nerve and Concurrent Vascular Variants: A Review.

The purpose of this paper is to review the current data on the coexistence of non-recurrent laryngeal nerve (RLN) and vascular variations. A systematic literature search was conducted on MEDLINE for case reports, original articles and reviews regarding the presence of non-RLN and coexisting vascular variants. From the literature search, 104 cases of non-RLN with confirmed vascular variants were reported. More specifically, 97.7% (n=101) of cases involved a right and 2.3% (n=3) a left non-RLN. The most common concurrent vascular variant reported with a right non-RLN was an aberrant right subclavian artery (97%; n=98). One case report (0.9%) of an intrathyroidal right common carotid artery was noted and 2 cases (1.9%) were associated with normal vascular anatomy. Furthermore, all 3 cases of a left non-RLN were associated with a right aortic arch, while 2 of them were also accompanied with situs inversus. The presence of vascular variations of the great vessels must prompt the surgeon to search for a non-RLN. Intraoperative neuromonitoring increases the detection rate of non-RLN. Further research is required to determine anatomic landmarks for the perioperative identification of a non-RLN, allowing its protection from potential injury.

Diagnosis, anatomy, and electromyography profiles of 73 nonrecurrent laryngeal nerves.

The purpose of this work was to compare methods of detecting nonrecurrent laryngeal nerves (NRLNs). Specificity and sensitivity were compared in three NRLN detection methods: CT, electromyography (EMG), and A-B point comparison. A total of 73 intraoperative pictures and 36 CT details of NRLNs are presented. Incidence of NRLN was 0.39%. Type I NRLN accounted for 50.7%, type IIA 45.2%, type IIB 4.1%. The NRLN median latency was 2.13 ms vs 3.00 ms median in an RLN control group (P < .001). When the threshold was set to 2.5 ms, EMG latency detection had 96.7% sensitivity and 91.6% specificity for detecting NRLN, and the A-B point comparison algrithm had 97.3% sensitivity and 92.5% specificity. Combining EMG latency detection with A-B point comparison achieved 100% sensitivity and specificity for detecting NRLN. This is the largest series of NRLN presented in the literature. Latency shorter than 2.50 ms combined with the A-B point comparison method is the ideal algorithm procedure for early NRLN identification.

Non Recurrent Laryngeal Nerve – Still a Surprise

Figure 1: Non-recurrent Laryngeal Nerve, Figure 2: Non-recurrent laryngeal nerve in a case of carcinoma thyroid identified intraoperative while performing total hyroidectomy Clinical Image: Non Recurrent laryngeal is an incidental finding in surgeries for thyroid disorders. Incidence is somewhere around 0.3 to 0.5%. We found a case of right non-recurrent laryngeal nerve in a case of carcinoma thyroid operated for total thyroidectomy (Figure 1 and Figure 2).

Non-recurrent laryngeal nerve in thyroid surgery: A report of case series in Vietnam and literature review

IntroductionThe non-recurrent laryngeal nerve (NRLN), which is found in 0.25–0.99 of the patients who undergo thyroid surgery, is a rare embryologically-derived variant of the recurrent laryngeal nerve (RLN). Identification and prevention of injury to the laryngeal nerve is one of the main issues in thyroid surgery; thus, thyroid surgeons should have adequate knowledge of all anatomical variations of the RLN. Presentation of casesAll four patients with the non-recurrent laryngeal nerve on the right side were performed thyroidectomy and discharged without any complications. During the procedure the surgeons found that the right laryngeal nerve was not recurrent and originated directly from the vagus nerve. Moreover, the right subclavian artery of these patients arose directly from the aortic arch. DiscussionNRLN can be easily damaged during surgery and its presence is closely related to subclavian artery anomaly. There are 2 types of NRLN in terms of its origin, nonetheless, in all variations of the NRLN and RLN, the nerve travels to the larynx at the level of cricothyroid joint, close to berry ligament. ConclusionThe NRLN is a rare, but clinically relevant structure and is associated to an increased risk in iatrogenic injury. Thorough anatomical knowledge and cautious dissection are essential to identify variants of RLN in order to minimize the risk of injury to the patient. Additionally, in embryological terms, the presence of NRLN is closely related to subclavian artery anomaly.

Nonrecurrent Laryngeal Nerve Identification and Preservation during Transoral Robotic Thyroidectomy

The nonrecurrent laryngeal nerve (NRLN), a rare, anatomic variation of the recurrent laryngeal nerve, is associated with increased injury risk during...