scholarly journals Nerve at risk: anatomical variations of the left recurrent laryngeal nerve and implications for thoracic surgeons

2020 ◽  
Vol 58 (6) ◽  
pp. 1201-1205
Author(s):  
Caecilia Ng ◽  
Claudia Woess ◽  
Herbert Maier ◽  
Verena-Maria Schmidt ◽  
Paolo Lucciarini ◽  
...  
Keyword(s):  
At Risk ◽  
Recurrent Laryngeal Nerve ◽  
Aortic Arch ◽  
Mediastinal Lymph Node ◽  
Demographic Data ◽  
Anatomical Variations ◽  
Laryngeal Nerve ◽  
Vagal Nerve ◽  
Ligamentum Arteriosum ◽  
Lung Cancer Patients

Abstract OBJECTIVES Recurrent laryngeal nerve (RLN) injury during thoracic surgery may result in life-threatening postoperative complications including recurrent aspiration and pneumonia. Anatomical details of the intrathoracic course are scarce. However, only an in-depth understanding of the anatomy will help reduce nerve injury. The aim of this study was to assess the anatomic variations of the intrathoracic left RLN. METHODS Left-sided vagal nerves and RLN were dissected in 100 consecutive Caucasian cadavers during routine autopsy. Anatomical details were documented. Available demographic data were assessed for possible correlations. RESULTS All nerves were identified during dissection. Variant courses were classified in 3 different groups according to the level at which the RLN separated from the vagal nerve: above the aortic arch, level with the aortic arch and below the aortic arch. We found 11% of RLN separating above the aortic arch and crossing the aortic arch at a considerable distance to the vagal nerve. In 48% of the RLN, the nerve split off when it was level with the aortic arch, and 41% of the RLN leave the vagal nerve in a perpendicular direction below the aortic arch. All nerves crossed the ligamentum arteriosum on the posterior side. No gender-specific differences were observed. CONCLUSIONS Mediastinal lymph node dissection in left-sided lung cancer patients puts the RLN at risk. With more detailed anatomical knowledge about its course, it is possible to avoid risking the nerve. Visualization will help protect the nerve.

scholarly journals A variant nerve that mimics the left recurrent laryngeal nerve: a case study in human anatomy

2015 ◽  
Author(s):  
Dickran Altounian ◽  
Cathy M Tran ◽  
Christina Tran ◽  
Allison Spencer ◽  
Alexandra Shendrik ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Aortic Arch ◽  
Ductus Arteriosus ◽  
Nerve Fibers ◽  
Laryngeal Nerve ◽  
Human Anatomy ◽  
Ligamentum Arteriosum ◽  
Left Recurrent Laryngeal Nerve ◽  
The One ◽  
Arch Of The Aorta

We describe a variant nerve in a human cadaver patient that parallels the course of the left recurrent laryngeal nerve (RLN). Like the normal left RLN, the variant nerve branches from the vagus nerve and wraps around the arch of the aorta, but it passes anterior and medial to the ligamentum arteriosum (= fetal ductus arteriosus) instead of behind it like the normal RLN. After recurring around the aorta, the variant nerve joins the esophageal plexus and also appears to connect to the cervical sympathetic chain. The bilaterally paired RLNs supply innervation not only to the larynx but also to the upper parts of the trachea and esophagus, in particular those parts derived from the 4th and 6th pharyngeal arches. We hypothesize that in this case, some of the nerve fibers to the trachea and esophagus were pulled down into the torso by the 4th embryonic aortic arch (= the arch of the aorta in adults), but passed cranial to the 6th embryonic aortic arch (= fetal ductus arteriosus). From where it recurs around the aorta to join the esophageal plexus, the variant nerve is very similar to the pararecurrent nerve in dogs, so there is at least a partial precedent in another placental mammal. Understanding the relationships of the embryonic pharyngeal and aortic arches and their adult derivatives is crucial for correctly identifying the RLN, especially when imposter nerves, like the one documented here, are present.

scholarly journals A variant nerve that mimics the left recurrent laryngeal nerve: a case study in human anatomy

2015 ◽  
Author(s):  
Dickran Altounian ◽  
Cathy M Tran ◽  
Christina Tran ◽  
Allison Spencer ◽  
Alexandra Shendrik ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Aortic Arch ◽  
Ductus Arteriosus ◽  
Nerve Fibers ◽  
Laryngeal Nerve ◽  
Human Anatomy ◽  
Ligamentum Arteriosum ◽  
Left Recurrent Laryngeal Nerve ◽  
The One ◽  
Arch Of The Aorta

We describe a variant nerve in a human cadaver patient that parallels the course of the left recurrent laryngeal nerve (RLN). Like the normal left RLN, the variant nerve branches from the vagus nerve and wraps around the arch of the aorta, but it passes anterior and medial to the ligamentum arteriosum (= fetal ductus arteriosus) instead of behind it like the normal RLN. After recurring around the aorta, the variant nerve joins the esophageal plexus and also appears to connect to the cervical sympathetic chain. The bilaterally paired RLNs supply innervation not only to the larynx but also to the upper parts of the trachea and esophagus, in particular those parts derived from the 4th and 6th pharyngeal arches. We hypothesize that in this case, some of the nerve fibers to the trachea and esophagus were pulled down into the torso by the 4th embryonic aortic arch (= the arch of the aorta in adults), but passed cranial to the 6th embryonic aortic arch (= fetal ductus arteriosus). From where it recurs around the aorta to join the esophageal plexus, the variant nerve is very similar to the pararecurrent nerve in dogs, so there is at least a partial precedent in another placental mammal. Understanding the relationships of the embryonic pharyngeal and aortic arches and their adult derivatives is crucial for correctly identifying the RLN, especially when imposter nerves, like the one documented here, are present.

scholarly journals Anatomical Variations of the Recurrent Laryngeal Nerve and Implications for Injury Prevention during Surgical Procedures of the Neck

Diagnostics ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 670
Author(s):  
Alison M. Thomas ◽  
Daniel K. Fahim ◽  
Jickssa M. Gemechu
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Surgical Procedures ◽  
Anatomical Variations ◽  
Laryngeal Nerve ◽  
Inferior Thyroid Artery ◽  
Branching Pattern ◽  
The Right ◽  
Relationship Of ◽  
Intrinsic Laryngeal Muscles ◽  
Formalin Fixed

Accurate knowledge of anatomical variations of the recurrent laryngeal nerve (RLN) provides information to prevent inadvertent intraoperative injury and ultimately guide best clinical and surgical practices. The present study aims to assess the potential anatomical variability of RLN pertaining to its course, branching pattern, and relationship to the inferior thyroid artery, which makes it vulnerable during surgical procedures of the neck. Fifty-five formalin-fixed cadavers were carefully dissected and examined, with the course of the RLN carefully evaluated and documented bilaterally. Our findings indicate that extra-laryngeal branches coming off the RLN on both the right and left side innervate the esophagus, trachea, and mainly intrinsic laryngeal muscles. On the right side, 89.1% of the cadavers demonstrated 2–5 extra-laryngeal branches. On the left, 74.6% of the cadavers demonstrated 2–3 extra-laryngeal branches. In relation to the inferior thyroid artery (ITA), 67.9% of right RLNs were located anteriorly, while 32.1% were located posteriorly. On the other hand, 32.1% of left RLNs were anterior to the ITA, while 67.9% were related posteriorly. On both sides, 3–5% of RLN crossed in between the branches of the ITA. Anatomical consideration of the variations in the course, branching pattern, and relationship of the RLNs is essential to minimize complications associated with surgical procedures of the neck, especially thyroidectomy and anterior cervical discectomy and fusion (ACDF) surgery. The information gained in this study emphasizes the need to preferentially utilize left-sided approaches for ACDF surgery whenever possible.

scholarly journals Non-recurrent inferior laryngeal nerve: a case report

2020 ◽  
Vol 7 (10) ◽  
pp. 3469
Author(s):  
Shah Urvin Manish ◽  
Boopathi Subbarayan ◽  
Saravanakumar Subbaraj ◽  
Tirou Aroul Tirougnanassambandamourty ◽  
S. Robinson Smile
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Nodular Goiter ◽  
Anatomical Variations ◽  
Laryngeal Nerve ◽  
Anatomical Landmarks ◽  
Inferior Laryngeal Nerve ◽  
Nonrecurrent Inferior Laryngeal Nerve ◽  
Aged Woman ◽  
Middle Aged Woman ◽  
The Right

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.

scholarly journals Intraoperative Recurrent Laryngeal Nerve Monitoring During Pediatric Cardiac and Thoracic Surgery: A Mini Review

2020 ◽  
Vol 8 ◽  
Author(s):  
Claire M. Lawlor ◽  
Benjamin Zendejas ◽  
Christopher Baird ◽  
Carlos Munoz-San Julian ◽  
Russell W. Jennings ◽  
...  
Keyword(s):  
At Risk ◽  
Cardiac Surgery ◽  
Recurrent Laryngeal Nerve ◽  
Pediatric Surgery ◽  
Tracheoesophageal Fistula ◽  
Laryngeal Nerve ◽  
Nerve Monitoring ◽  
Endotracheal Tubes ◽  
Surface Electrodes ◽  
Recurrent Laryngeal Nerve Monitoring

Objective: Review techniques for intraoperative recurrent laryngeal nerve (RLN) monitoring during pediatric surgery for esophageal atresia, tracheoesophageal fistula, tracheobronchomalacia, and cardiac surgery.Summary Background Data: Literature was reviewed for reports of intraoperative recurrent laryngeal nerve monitoring in cervical, thoracic, and cardiac surgical procedures which place the RLNs at risk for injury.Methods: Review paper.Results: The RLN is at risk during pediatric surgery for esophageal atresia, tracheoesophageal fistula, tracheobronchomalacia, and cardiac surgery. Intraoperative nerve monitoring has decreased rates of RLN injury in thyroid surgery. Intraoperative RLN monitoring techniques appropriate for pediatric surgery are discussed, including endotracheal tubes with integrated surface electrodes, adhesive surface electrodes for smaller endotracheal tubes, endolaryngeal electrodes, and automatic periodic continuous intra-operative stimulation.Conclusions: Multiple techniques exist to monitor the RLN in children undergoing cervical, cardiac, and thoracic surgery. Monitoring the RLN during procedures that place the RLNs at risk may help decrease the rate of RLN injury.

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