title: Prediction of nonrecurrent laryngeal nerve before thyroid surgery--experience with 1825 cases.
abstract: BACKGROUND
  Nonrecurrent laryngeal nerve (NRLN) is a rare anatomic anomaly, which often co-occurs with aberrant right subclavian artery (ARSA). With this large case series, we present our experience of predicting the presence of NRLN by the means of chest X-ray film, thoracic computed tomography (CT), and ultrasonography.
  
  
  METHODS
  A prospective, nonrandomized study has been carried out. A total of 1825 patients with various thyroid disorders scheduled for surgery were recruited between January 2006 and July 2012. All patients underwent preoperative chest X-ray examination. Those suspected with ARSA further underwent thoracic CT scan. Unsuspected patients who had NRLN revealed by surgery were analyzed with ultrasonography postoperatively.
  
  
  RESULTS
  A total of 41 patients (2.25%) were suspected to have ARSA by X-ray, of those 19 (46.3%) were confirmed by thoracic CT and proven to have NRLN upon subsequent surgery. No NRLN injury was inflicted. For the remaining 22 cases, CT scan suggested a normal right subclavian artery and none had NRLN upon surgery. For the 1784 unsuspected patients, 4 (0.22%) were discovered to have NRLN upon surgery, of those one was injured. For the 19 predicted NRLN, the time used for identifying the nerve was significantly shorter than the four cases with unsuspected NRLN (t = -15.978; P = 0.000). After the operation, all these unsuspected NRLN were confirmed to have ARSA by ultrasonography.
  
  
  CONCLUSIONS
  Patients scheduled for thyroid surgery should be screened for ARSA upon routine chest X-ray and thyroid ultrasonography before surgery. Detection of ARSA can accurately predict the existence of NRLN; hence prevent NRLN injury during subsequent surgery.
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Ri-xiang
authors.initials: RX
authors.lastname: Gong
authors.affiliation: Department of Thoracocardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Shu-hua
authors.initials: SH
authors.lastname: Luo
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Yan-ping
authors.initials: YP
authors.lastname: Gong
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wei
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Zhi-hui
authors.initials: ZH
authors.lastname: Li
authors.affiliation: Department of General Surgery, Municipal Medical Center, Qionglai, Sichuan, China.
authors.forename: Jia-bin
authors.initials: JB
authors.lastname: Huang
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Zhen-lin
authors.initials: ZL
authors.lastname: Li
authors.affiliation: State Key Laboratory of Biotherapy, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Jesse
authors.initials: J
authors.lastname: Li-Ling
authors.affiliation: Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China. Electronic address: ncl2000@126.com.
authors.forename: Jing-qiang
authors.initials: JQ
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D061224:Laryngeal Nerve Injuries / Q000453:epidemiology / Q000517:prevention & control*; D007823:Laryngeal Nerves / Q000002:abnormalities* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000706:statistics & numerical data; D011446:Prospective Studies; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D013348:Subclavian Artery / Q000601:surgery; D013961:Thyroid Gland / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Aberrant right subclavian artery; Cervical ultrasound; Computer tomography; Nonrecurrent laryngeal nerve; Thyroid surgery