The anatomy of the lower laryngeal nerve makes thyroid surgery. This article highlights the normal anatomy, anatomical variants and ways to identify the nerve. Anatomical variations of the recurrent laryngeal nerve in. Gray 7 and pernkopf 8 contributed their colossal text on gross human anatomy more than half a century. The recurrent laryngeal nerve provides motor innervation to the intrinsic muscles of the larynx, which provide the majority of movement of the vocal cords see fig. Oct 15, 2014 the left recurrent laryngeal nerve branches from the vagal nerve just below the ligamentum arteriosum at the level of the aortopulmonary ap window and moves dorsally under the aortic arch in the direction of the left te groove fig. Injury of the recurrent laryngeal nerve rln is fortunately no longer a very common complication of thyroid surgery.
Therefore, surgeons should be mindful of this entity. Functions anatomy subdivisions cartilages vocal cords. The recurrent and superior laryngeal nerves download. The recurrent laryngeal nerve rln runs either in front of or behind the fig. An experimental study on the laryngeal electromyography and visual observations in varying types of surgical injuries to the unilateral recurrent laryngeal nerve in.
Contradictory opinions are found in the literature concerning the precise anatomy and role of the inferior laryngeal nerve, the terminal portion of the recurrent laryngeal nerve. The right and left nerves are not symmetrical, with the left nerve looping under the aortic arch. Detailed anatomical knowledge of the intralaryngeal course of the recurrent laryngeal nerve rln is critical for performing complex thyroid surgery, partial laryngeal surgery, and selective reinnervation of the larynx specifically for rehabilitation of bilateral vocal fold paralysis and laryngeal transplant. 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. A variant nerve that mimics the left recurrent laryngeal nerve peerj. We think this is the most useful anatomy picture that you need. The recurrent laryngeal nerve rln branches off the vagus nerve and supplies function to some muscles of the larynx voice box. Incidence of vocal cord paralysis with and without recurrent. Morphology and functional anatomy of the recurrent laryngeal. Surgical management of the recurrent laryngeal nerve in. The nerves control the movement of the larynx and the vocal cords.
Elizabeth davis, in equine internal medicine fourth edition, 2018. What you need to know about the recurrent laryngeal nerve. Introduction the thyroid surgery requires anatomy awareness of the front and side of the neck, pharynx, laryngeal structures and any anatomical variation on the recurrent nerve 1. Recurrent laryngeal nerve, which supplies nerve function to all of the muscles that are intrinsic to contained fully within the larynx with the exception of the cricothyroid muscles recurrent is part of the name because of the rlns unusual course. Recurrent laryngeal nerve paralysis linkedin slideshare. A rear view of the thyroid, showing the parathyroids lying on the back of the thyroid, close to the recurrent laryngeal nerve the parathyroid glands are tancoloured, beanshaped structures, about the size of a grain of rice, weighing around 3040 mg each. This article highlights the normal anatomy, anatomical variants and ways to identify the nerve as the. The recurrent and superior laryngeal nerves springerlink. The anatomy of the recurrent laryngeal nerve is complex and different on both sides of the body. Several methods have been proposed for identifying and localizing the rln based on vocal cord motion produced by electrical stimulation of the nerve.
You have two, one on each side, as you do with other nerves. There are two recurrent laryngeal nerves right and left in the human body both arising from the vagus. Recurrent laryngeal nerve definition of recurrent laryngeal. Right recurrent laryngeal nerve can take a non recurrent course and can present as a non recurrent laryngeal nerve which is a rare entity. A 50yearold woman was presented to our department with a nodule in the right thyroid lobe, and she reported no voice changes. The recurrent laryngeal nerve may be traumatized during surgery on the thyroid and parathyroid glands. The right recurrent laryngeal nerve 1 the right and left nerves are not symmetrical. Because of the inefficiencies of the routing the nerve takes, its often hailed as one of the most striking cases against intelligent design. Quantitative analysis of the anatomy of the epineurium of. These muscles are innervated by both recurrent laryngeal nerves and will remain functional in cases of unilateral vocal fold paralysis secondary to recurrent laryngeal nerve palsy. A systematic approach to the recurrent laryngeal nerve. There are two recurrent laryngeal nerves, right and left. An experimental study on the laryngeal electromyography and visual observations in varying types of surgical injuries to the unilateral recurrent laryngeal nerve in the neck. The presence of an nrln significantly increases the risk of iatrogenic injury and operative complications.
Vocal cord paralysis vcp due to recurrent laryngeal nerve rln dysfunction may herald the presence of mediastinal disease, including a variety of neoplastic, inflammatory, and vascular conditions 1,2. The rln is consistently present superior to the inferior. The recurrent laryngeal nerve rln is a branch of the vagus nerve, which carries motor, sensory and parasympathetic fibers to the larynx. Anatomy and etiology etiologies of adult vocal paralysis are varied by the site of the lesion as well as the extent and cause of the damage. The anatomy of the inferior laryngeal nerve schweizer. The anatomy of the nerve appears more constant along its distal segment near the cricothyroid joint, which is our surgical approach to the initial identification of the nerve. There are usually four of them, with two on each side, and they lie on the posterior surface of the thyroid gland. May 05, 2012 recurrent laryngeal nerve palsy on integrated positron emission tomographycomputed tomography. The branches provide both sensory and motor fibers. 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. Particular attention needs to be paid to identifying and preserving the recurrent laryngeal nerve rln, the external branch of the superior laryngeal nerve sln figure and the parathyroid glands. The non recurrent inferior laryngeal nerve nirln is a rare anomaly 0. The main trunk, bifurcation point, and terminal branches of. Motor all intrinsic muscles are supplied by the recurrent laryngeal nerve, except for the cricothyroid which is supplied by the external laryngeal nerve.
Neuroanatomy of the equine dorsal cricoarytenoid muscle. Anatomical variations of recurrent laryngeal nerve. Intralaryngeal anatomy of the recurrent laryngeal nerve. The left recurrent laryngeal nerve branches from the vagal nerve just below the ligamentum arteriosum at the level of the aortopulmonary ap window and moves dorsally under the aortic arch in the direction of the left te groove fig. 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. Besides the morphology of the nerve branches, intraoperative evaluation of their functional anatomy may be useful to preserve motor activity. Superior laryngeal nerve anatomy sln branches from the vagus and innervates the cricothyroid muscle the external branch controls longitudinal tension of the vocal folds and voice pitch symmetric contraction of the cricothyroid muscle raises the anterior cricoid cartilage resulting in narrowing of the. The left recurrent laryngeal nerve curves medially around the aortic arch during development and is approximately 1 m long. Nov 15, 2018 the recurrent laryngeal nerve rln supplies all the muscles in the larynx voice box apart from the cricothyroid muscles. 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. Previous anatomic studies of the recurrent laryngeal nerves rlns have described the variability in the course of the rln. Recurrent laryngeal nerve an overview sciencedirect topics.
Because of the inefficiencies of the routing the nerve takes, its often hailed as one of. Dec, 2014 recurrent laryngeal nerve the recurrent laryngeal nerve is a myelinated nerve. Pdf surgical anatomy of recurrent laryngeal nerve during. Sercarz, md functional laryngeal reinnervation depends upon theprecise reinnervation ofthe laryngeal abductor and adductor muscle groups.
However, the two rlns are different from other nerves in that their courses are not symmetrical. Nevertheless, it can be quite troublesome for patients when it does occur. Recurrent laryngeal nerve radiology reference article. Anatomical variations of the recurrent laryngeal nerve in chinese. To understand the course of the right rln one has to understand the course of the right vagus nerve first. Injury to the recurrent laryngeal nerve is one of the most severe complications of thyroid surgery. To describe and evaluate a four step systematic approach to dissecting the recurrent laryngeal nerve rln starting at the cricothyroid junction during thyroid surgery subsequently referred to as the retrograde medial approach. 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. Electrophysiologic recurrent laryngeal nerve monitoring. The larynx is involved in producing speech, breathing and it also protects the trachea. The recurrent laryngeal nerve thyroid surgery wiley online. Surgical anatomy a detailed knowledge of thyroid anatomy is a prerequisite for thyroid surgery.
Key words anatomy, larynx, recurrent laryngeal nerve, reinnervation. Left side view of rln position inferior thyroid artery and it is essential to locate this nerve during a thyroidectomy. Surgical anatomy of the recurrent laryngeal nerve revisited. Implications for laryngeal reinnervation, authoredward j damrose and robert y. Anatomical perspective lalruatkimi k balasubramanian thiagarajan stanley medical ollege abstract. The recurrent and superior laryngeal nerves gregory w. Jul 26, 2019 we hope this picture recurrent laryngeal nerve anatomy can help you study and research. Anatomy of recurrent laryngeal nerve rln dent1 pbl 3.
Many techniques have been described to reduce the risk of nerve injury. Anatomy of recurrent laryngeal nerveanatomy of recurrent. It was lahey, a doyen of thyroid surgery, who suggested that careful dissection of the nerve would definitively decrease the number of injuries. Aug 17, 2016 recurrent laryngeal nerve paralysis 1. The recurrent laryngeal nerve can be a real challenge to the surgeon operating in its area. Moreover, operative damage to this nerve beyond the thyroid area is seldom described. Additional findings the relationship of the laryngeal branches of. An awareness of the surgical anatomy and the possible dispositions of the recurrent laryngeal nerve rln is helpful in avoiding its injury during thyroidectomy. Quantitative analysis of the anatomy of the epineurium of the. 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. Spectrum of 18ffdg petct findings in oncologyrelated recurrent laryngeal nerve palsy.
The recurrent laryngeal nerve rln shows some anatomical variations that can potentially compromise the safety of thyroid surgery. The paths of the left and right recurrent laryngeal nerves vary slightly with the left recurrent laryngeal nerve dividing from the main vagus nerve at the level of the aortic arch. Our aim was to provide a comprehensive metaanalysis of the overall prevalence of the nrln, its origin, and its association with an aberrant subclavian artery. The recurrent laryngeal nerve rln is a branch of the vagus nerve cranial nerve x that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. The right rln is shorter and makes a quick entry and exit at the apex of the right chest. Although vocal cord function contributes to the ability to breathe, swallow, and phonate effectively, up to 40% of individuals with vcp may be asymptomatic. The laryngeal nerve is a nerve branching down from the vagus nerve towards the larynx. The result is some movement of the arytenoid cartilage on the affected side due to contraction of the bilaterally innervated interarytenoid muscles, often confused. It arises almost exclusively on the right howtocitethisarticlehenry et al. The surgical anatomy of the recurrent laryngeal nerve wiley online. Loss of large myelinated nerve fibres of the recurrent laryngeal nerve in patients with multiple system atrophy and vocal cord palsy journal of. The recurrent laryngeal nerves and the terminal parts of the inferior thyroid arteries lay in the fat which filled this space.
A novel variation of the recurrent laryngeal nerve bmc. From there, like the recurrent laryngeal nerve on the right, it moves upward to the larynx. Pdf the recurrent laryngeal nerve can be a real challenge to the surgeon operating in its area. The unique anatomy of the recurrent nerves still determines their vulnerability, however, and remains a basic unalterable fact in this disorder. The external branch of the superior laryngeal nerve. Recurrent and superior laryngeal nerves the annals of thoracic. Background the non recurrent laryngeal nerve nrln is a rare embryologicallyderived variant of the recurrent laryngeal nerve rln. Berke, md losangeles, california ming ye, md joel a. It has been suggested that tension applied by the left recurrent laryngeal nerve as it wraps around the ductus arteriosus could provide a means of support that would permit the ductus to develop as a muscular artery, rather than an elastic artery grays anatomy, 39th edition 2005, p. She had no history of surgery or radiation to the head or neck. A new classification system for recurrent laryngeal nerve anatomy is proposed. Anatomical variation, recurrent laryngeal nerve, surgery, mali 1. Recurrent laryngeal nerve the recurrent laryngeal nerve is a myelinated nerve.
Pdf anatomy of the thoracic recurrent laryngeal nerves from a. A branch of the vagus nerve curving upward, on the right side around the root of the subclavian artery, on the left side around the arch of the aorta, then passing superiorly, posterior to the common carotid artery between the trachea and the esophagus to the larynx. Anatomy of the external branch of the superior laryngeal. Their movement is controlled by the intrinsic muscles of the larynx the majority of which are innervated by the recurrent laryngeal nerve an exception is the cricothyroid muscle. The right nriln is associated with a right subclavian artery arising directly from the aortic arch. Several anatomic variations of the nerve increase the likelihood of iatrogenic damage.
The nerve which connects the middle cervical ganglion with the recurrent laryngeal nerve, pierces the prevertebral fascia to come into the same fascial plane as the recurrent laryngeal nerve fig. For example, laryngeal exam may not be performed preoperatively and postoperatively, a variety of. Practitioners interested in maximizing the information obtained from laryngeal imaging must be familiar with laryngeal anatomy. Such anomalies can lead to difficulty in locating the laryngeal nerve during thyroid surgeries and there are higher chances of it being injured. The right and left nerves are not symmetrical, with the left nerve looping under the aortic arch, and the right nerve looping under the right. Anatomical variations of the recurrent laryngeal nerve rln, such as an extralaryngeal terminal bifurcation etb, threaten the safety of thyroid surgery.
169 1537 332 363 772 216 1565 206 172 1386 583 1014 228 1474 1633 1214 41 60 835 658 571 88 417 1465 20 304 1486 76 1089 1145 1623 1320 626 1175 1401 1207 1413 557 1464 1288 1135 1437 688 783 869 1408 465 553 131 1289