• Korean Journal of Bronchoesophagology
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• v.4 no.1
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• pp.132-136
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• 1998

Nonrecurrence of the inferior laryngeal nerve always results from a vascular anomaly during embryonic development of the aortic arches. The nonrecurrent inferior laryngeal nerve is important clinically for two reasons, it is vulnerable during thyroid surgery and it is associated with difficulty in swallowing. It can be suspected preoperatively from signs associated with the vascular anomaly : dysphagea, thoracic x-ray images showing evidence of retroesophageal subclavian artery, or situs inversus viscerum. If such signs are noted, a barium swallow test and chest computed tomography are justified. We experienced a case of Rt. nonrecurrent inferior laryngeal nerve, which is diagnosed thyroid papillary carcinoma.

• Korean Journal of Head & Neck Oncology
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• v.22 no.1
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• pp.3-7
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• 2006

Purpose: The nonrecurrent laryngeal nerve(NRLN) is a rare anomaly that is associated with the developmentally aberrant subclavian artery. Although rare on the right side and exceptional on the left, an aberrant nonrecurrent pathway for RLN represents a major surgical risk. Three course variations of right NRLN can be distinguished: descending(type I) , horizontal(type II), ascending(type III). This study is performed to characterize the variations of NRLN, associated vascular anomaly, and proper surgical methods for preventing nerve damage. Materials and Methods: Between January 1998 and March 2006 3,381 thyroidectomy were performed at our institution, and during these operations a nonrecurrent laryngeal nerve was observed in 13 cases (0.38%). There were 1 men and 12 women with a median age of 48 years(range 28-57). All of them are identified on the right side. Results: In all cases, there were no clinical symptoms observed preoperatively. The nerve anomaly was diagnosed preoperatively in only one case. There were type I variations of right RLN in 2 cases and type II variations in 11 cases. The retroesophageal aberrant right subcalvian artery; no innominate(brachiocephalic) artery was found and the right common carotic artery was arising directly from the aortic arch, was seen in 12 cases. A vocal cord palaysis caused by NRLN damage during operation was observed in one patient(7.6%) , where the nerve was close to the superior thyroid artery. No other complications were noted. Conclusion: It can be possible to predict NRLN from signs associated with the vascular anomaly; clinical symptoms or imaging studies. When an vascular anomaly is not detected preoperatively, overlooking possibility of NRLN may lead to severe operative morbidity. Hence, It is most important to identify all the thyroid structures carefully during thyroid surgery and to be aware of the possibility of anatomic variations of RLN.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.2
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• pp.188-191
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• 2000

In thyroid and parathyroid surgery, damage to the recurrent laryngeal nerve(RLN) is the most common iatrogenic cause of vocal cord paralysis. Identification and preservation of the BLNs and meticulous technique can siginificantly decrease the incidence of this complication. We experienced one case of NRRLN in a patient with the parathyroid adenoma. During the dissection, there was no branch to be considered as RLN in tracheoesophageal groove. While searching for the RLN, We found a white structure coursing horizontally at the level of cricoid cartilage directly arising from the vagus nerve in the carotid sheath. That structure was nonrecurrent recurrent laryngeal nerve(NRRLN) and NRRLNs are exceedingly rare. Awareness of the possibility of NRRLN will prevent the surgeon from accidentally severing one if it is encountered during surgery.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.67-70
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• 2007

Background and Objectives: The nonrecurrent laryngeal nerve(NRLN) is exceedingly rare nerve anomaly that is associated with developmentally aberrant subclavian artery. The presence of NRLN is associated with an increased risk of vocal cord palsy in thyroid surgery. The purpose of this study is to investigate its prevalence, associated vascular anomaly and necessity of recognizing its possibility for prevention of intraoperative nerve damage. Materials and Methods: Between January 2004 and December 2006, 583 thyroidectomy were performed at our hospital. Of these cases, 529 cases(90.7%) were checked preoperative neck CT. Results: Patients with preopreative neck CT, 6 cases show the retroesophageal abberant right subclavian artery that arising directly form the aortic arch. 5 cases of these 6 cases(5/6, 83.3%) and of 583 patients(5/583, 0.8%) performed thyroid surgery were identified NRLN per-operatively. All of them are identified on the right side. There were 4 women and 1 man. In all cases, there were no clinical symptoms. I case was performed only left hemithyroidectomy, so we cannot identified NRLN. No vocal cord palsy was observed. Conclusion: It is possible to predict NRLN from preoperative neck CT. When NRLN is suspected, careful, complete dissection of the nerve is always advocated. These process can reduce the operative morbidity.

• Korean Journal of Head & Neck Oncology
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• v.9 no.2
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• pp.183-192
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• 1993

This study reports a prospective analysis of anatomical variations of recurrent laryngeal nerves during 300 thyroidectomies. During thyroidectomies for variable thyroid diseases. the course of recurrent laryngeal nerve was completely isolated from root of neck to the inferior comus of thyroid cartilage. In left side, nerve(53.7%) predominantly ran posterior to the inferior thyroidal artery(p<0.05) but in right side there was no predominant pattern. There were three nonrecurrent laryngeal nerves in the right side. About half of the cases in both sides(51.2% in right, 50.5% in left side) had one or more branches before terminating at cricothyroidal muscles. The average length of branches from inferior comus of thyroid cartilage to the origination of individual branch were l2.0mm in right side and 13.3mm in left side. In right side, majority(50.7%) of nerves ran though paratracheal space but difference did not reach the statistical but in left side, majority(88.3%) ran through tracheoesophageal groove and it was the dominant pattern(p<0.01), the overall status of passages of the nerve were relatively straight in left side(straight 87.8%, oblique 52.1%).