Nonrecurrent laryngeal nerve nrln is a rare anomaly which is reported in 0. The laryngeal nerve is a nerve branching down from the vagus nerve towards the larynx. Neck ultrasonography for detection of nonrecurrent. Non recurrent nerve is a very rare variation of the inferior laryngeal nerve. A very rare such variant, almost exclusively on the right side,is the nonrecurrent inferior laryngeal nerve nriln. The nonrecurrent laryngeal nerve is an anomaly of the rln because its origin is cervical and it runs a direct course from the vagus nerve to the larynx without looping around any of the above named structures.
The recurrent laryngeal nerve receives sensory innervation from the trachea, esophagus and pyriform sinus before it enters the larynx deep to the inferior constrictor muscle and posterior to the cricothyroid articulation. If not anticipated intraoperatively, these abnormalities can put the nerve at risk, with subsequent vocal cord palsy. Of note, rlnp occurs more frequently on the left, which adds to the clinical challenge. A study was undertaken between august 2005 and august 2006.
Nonrecurrent laryngeal nerve 2014, volume 30, issue 2. The nonrecurrent inferior laryngeal nerve nriln is a rare anatomic variation associated with subclavian artery abnormalities. The presence of an nrln significantly increases the risk of. Non recurrent laryngeal nerve non rln is a rare anatomic variant with a reported incidence of 0. The book is visually oriented with color illustrations and photomicrographs embracing all aspects of recurrent laryngeal nerve anatomy including branching patterns, relationship of the nerve and the inferior thyroid artery and the non recurrent recurrent laryngeal nerve. Recognition of variations of the inferior laryngeal nerve is essential.
The non recurrent inferior laryngeal nerve nriln is a nerve anomaly that can be associated with an increased risk of vocal fold paralysis. We report the case of a 53yearold lady who underwent. The recurrent laryngeal nerve rln, also known as the inferior laryngeal nerve, is a branch of the vagus nerve cn x which has a characteristic loop around the right subclavian artery on the right and the aortic arch on the left before returning up to achieve the tracheoesophageal groove and then the larynx summary. Because of the inefficiencies of the routing the nerve takes, its often hailed as one of the most striking cases against intelligent design. Vincristineinduced recurrent laryngeal nerve palsy. The availability of a preoperative diagnosis of nrln may reduce the risk of nerve injuries. Careful dissection of the rln during surgery reduces the risk of damage. In these cases the risk of surgical damage can be increased. Background the non recurrent laryngeal nerve nrln is a rare embryologicallyderived variant of the recurrent laryngeal nerve rln. The right recurrent laryngeal nerve passes caudal to the right subclavian artery rather than the aorta and ductus arteriosus, but otherwise its course is identical to that of the left. Nonrecurrent laryngeal nerve and concurrent vascular. Such anomalies can lead to difficulty in locating the laryngeal nerve during thyroid surgeries and there are higher chances of it being injured. Therefore, surgeons should be mindful of this entity. We describe a new method for its identification using.
Non recurrent laryngeal nerve nrln is a rare anomaly which is reported in 0. The nerve was noted to emerge deep to the carotid artery figure 3. Nonrecurrent inferior laryngeal nerve identification. The patient was a 34yearold male suffering from thyroid papillary carcinoma. Injury to the nerve results in significant morbidity. Very rarely, thyroid surgeons may encounter a non recurrent laryngeal nerve. Recurrent laryngeal nerve paralysis linkedin slideshare. In this condition, which has a frequency of between. Inflammatory complications can also affect the patients longterm prognosis4,5. Cause of recurrent laryngeal nerve paralysis following. The presence of an nrln significantly increases the risk of iatrogenic injury and operative complications. A total of 253 adult patients undergoing thyroid surgery were included in this prospective, non randomized study. In knottenbelt and pascoes color atlas of diseases and disorders of the horse second edition, 2014. Congenital laryngeal palsy genetic and rare diseases.
A nonrecurrent laryngeal nerve nrln is a rare anatomical variation in which the nerve enters the larynx directly off the cervical. In this case report, we present a non recurrent laryngeal nerve abnormality in a patient who underwent parathyroidectomy, thyroidectomy and functional. Present the peroperative detection of a nonrecurrent inferior laryngeal nerve and discuss the importance of its identification, when the nerve is anomaly or not, during. Non recurrent laryngeal nerve encountered during total. Recurrent laryngeal nerve an overview sciencedirect topics.
During the performance of 2101 thyroid operations, 3496 recurrent laryngeal nerves were identified and exposed. It is therefore important to report on and understand these abnormalities. The non recurrent laryngeal nerve nrln is a rare anatomic variation that every head and neck surgeon must be aware of, in order to avoid intraoperative injury which leads to postoperative morbidity. A new classification system for recurrent laryngeal nerve anatomy is proposed.
The non recurrent inferior laryngeal nerve nrln represents a risk factor for nerve injury during thyroid surgery. The subcarinal space contains station 7 lymph nodes fig. The incidence of nonrecurrent laryngeal nerve is 0. Non recurrent laryngeal nerve nrln is a rare anatomical variant 0. We investigated the nonrecurrent inferior laryngeal nerve nriln, an important variant in the course of the inferior laryngeal nerve iln. Non recurrence and extralaryngeal branching are 2 of the more frequently encountered anomalies of the recurrent laryngeal nerve. The non recurrent inferior laryngeal nerve occurs at a frequency of about 0. Pdf o nervo laringeo inferior naorecorrente nlinr e uma variacao anatomica rara associada a anomalias da arteria subclavia. Stedman in 1823 4, 5 during a cervicothoracic dissection made at the royal academy of copenhagen, when he also noticed the arterial anomaly accompanying it. The non recurrent inferior laryngeal nerve nriln is a rare anatomic variation associated with subclavian artery abnormalities. Very rarely, the inferior laryngeal nerve exits the vagal nerve in the cervical region and enters the larynx with a short and straight course from its origin. A right non recurrent laryngeal nerve rln was identified medially, near the cricothyroid muscle, and traced laterally. The identification of a non recurrent laryngeal nerve may be difficult.
The recurrent laryngeal nerve rln branches off the vagus nerve and supplies function to some muscles of the larynx voice box. It provides innervations to all the important intrinsic muscles of the larynx, with the exception of the cricothyroid which is supplied by the external laryngeal nerve. In these cases lack of information about this situation increases the risk of iatrogenic damage of the nerve. The incidence of non recurrent laryngeal rln nerve is around 0. Anatomic characteristics, identification, and protection of the nonrecurrent. A case of thyroid cancer with a nonrecurrent inferior. Although the left recurrent laryngeal nerve rln is only one element of this physiology, it is a structure that is at uniquely high risk of damage during neonatal aortic arch reconstruction. The non recurrent laryngeal nerve nrln is a rare variant of the recurrent laryngeal nerve rln that takes an aberrant course, not descending into the thorax as is usual fig.
Abstract background the nonrecurrent laryngeal nerve nrln is a rare embryologically derived variant of the rln. Keywords arteria lusoria, recurrent laryngeal nerve, metaanalysis, non recurrent laryngeal nerve, anatomy introduction the non recurrent laryngeal nerve nrln is a rare variant of the recurrent laryngeal nerve rln that takes an aberrant course, not descending into the thorax as is usual fig. It represents 15%20% of all cases of congenital anomalies of the larynx. The nonrecurrent laryngeal nerve nrln is a rare variant of the. The cause of bilateral paralysis of the vocal cords is often unknown idiopathic. Of the 1776 visualized nerves on the right side, 6 were found to be non. The nonrecurrent inferior laryngeal nerve nirln is a rare anomaly 0. The recurrent and superior laryngeal nerves gregory w. Course of the left vagus nerve and left recurrent laryngeal nerve in a human, a giraffe, and supersaurus. We present a unique case of a non recurrent laryngeal nerve with a. Recurrent course and can present as a non recurrent laryngeal nerve which is a rare entity. The left rln courses around the distal aortic arch and the patent ductus arteriosus close to the area of dissection needed to reconstruct the distal arch. The aim of this study is to investigate the traveling patterns of nrlns and its relationships to inferior thyroid arteries itas.
A nonrecurrent inferior laryngeal nerve nriln, a variant of the right recurrent laryngeal nerve, was also noted. An unusual anomaly is the socalled non recurrent laryngeal nerve. O nervo laringeo inferior naorecorrente nlinr e uma variacao anatomica. Vincristine vcr is a chemotherapeutic agent used widely in the treatment of hematologic and solid tumors. Nonrecurrent laryngeal nerve and aberrant vasculature. The nonrecurrent laryngeal nerve nrln is a rare embryologicallyderived variant of the recurrent laryngeal nerve rln. An anatomical trap article pdf available june 2014. Non recurrent laryngeal nerve with right aberrant subclavian artery in recurrent case of papillary carcinoma of thyroid. A metaanalysis and clinical considerations article pdf available in peerj 53 march 2017 with 1,089 reads how we measure reads.
Surgical mediastinal lymph node sampling for staging of. Complicationfree thyroid surgery is mainly based on the motor integrity of the recurrent laryngeal nerve rln. This anomaly is called nonrecurrent laryngeal nerve. Electrophysiologic recurrent laryngeal nerve monitoring during. A total of 6110 patients were operated in our hospital between 1 january 2005 and 31 december 20 for various goiters 5429 and various types of hyperparathyroidism 618.
A non recurrent inferior laryngeal nerve is a rare anomaly in which the nerve enters the larynx directly off the cervical vagus nerve, without descending to the thoracic level. Recurrent laryngeal nerve radiology reference article. Electrophysiologic recurrent laryngeal nerve monitoring. Non recurrent laryngeal nerve in thyroid surgery a n hisham ms, a sarojah ms, a alvin ms, nteast and endoetine surgical unit, departmentofsurgety,kualalumpurhospital, kualalumpur, malaysia introduction the non recuncntlaryngeal nerve nrin is a rare clinical entity. The recurrent and superior laryngeal nerves pdf download. Recurrent laryngeal nerve injury causes and surgery. In that case, the nerve enters the larynx directly after its origin from the cervical vagus. In most series the incidence is reportedto beless than 1%. A case of a 63year old lady with a non rln and an aberrant subclavian artery was described. Preoperative ultrasonography us has been suggested as a. Pdf thyroid gland related nonrecurrent laryngeal nerve is encountered as an uncommon anatomical exception to its commoner cousin the. Cautery should be avoided in this area due to the risk of injury to the left recurrent laryngeal nerve.
Because of the anatomical variations of the nerve, preservation of the nerve is the optimal strategy during surgery. The reason for laterality is a congenital abnormality of the right subclavian artery. The recurrent laryngeal nerve and the inferior thyroid. It then branches into the superior and recurrent laryngeal nerves rln, of which the latter is remarkably interesting from the point of view of evolutionary biology. The relationship between the nonrecurrent laryngeal nerve. The recurrent laryngeal nerve rln innervates all the important laryngeal muscles except the cricothyroid. Normally, the right recurrent laryngeal nerve loops around the right subclavian artery to ascend between the esophagus and trachea before entering the larynx as the right inferior laryngeal nerve. The recurrent laryngeal nerves course on both sides of the trachea, and at the point of entrance to the larynx they are located just lateral to the. Case report nonrecurrent laryngeal nerve and aberrant. Normal right recurrent laryngeal nerve a and right nonrecurrent laryngeal nerve in the presence of an aberrant subclavian artery b. However, the two rlns are different from other nerves in that their courses are not symmetrical. A brief survey of the literature relevant to this anatomical abnormality is included, and its importance in the performance of thyroid surgery is. There is progressive degeneration of large myelinated axons, particularly in the distal portions of the nerve, and secondary neurogenic atrophy of the intrinsic laryngeal muscles that the nerve innervates.
It may affect one unilateral or both bilateral vocal cords. A new type of nonrecurrent inferior laryngeal nerve in a. Four parathyroid glands were identified and preserved. Neuropathy of this nerve results in laryngeal hemiplegia which is defined as a failure of abduction of a structurally normal. The non rln nrln is a rare anatomical anomaly of the rln, with an incidence of 0. Identification and preservation of recurrent laryngeal nerve inferior laryngeal nerve is one of the most important step during thyroid and parathyroid surgery. He underwent right lobe dissection and d2 dissection. The nonrecurrent laryngeal nerve a rare phenomenon.
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