title: A Closer Look at the Recurrent Laryngeal Nerve Focusing on Branches & Diameters: A Prospective Cohort Study.
abstract: OBJECTIVE
  We aimed to investigate the anatomical characteristics of the recurrent laryngeal nerve (RLN) highlighting on its diameter and branching pattern.
  
  
  METHODS
  We prospectively collected 215 patients (178 female, 37 male) who underwent thyroid/parathyroid surgery during over a 2-year period. Apart from demographic features and surgical data, diameter of RLNs, and their branches and as well as branching distance (distance between the point of bifurcation and the laryngeal entry of RLN) were recorded.
  
  
  RESULTS
  In 215 patients, 378 RLNs were assessed and 42% (n = 159) bifurcated RLNs were observed. The bifurcation rate was similar on the right and left side(s) of the neck (40% and 44%, respectively; p = 0.47). In those, who underwent bilateral exploration, in the case of bifurcation on the first side of the neck, the possibility of contralateral bifurcation was approximately 50%, whereas this rate was found to be only 30% in those with nonbranching RLNs. Mean branching distance was 18 ± 9 mm, and it was similar on the right and left sides (17 and 19 mm, respectively). Approximately 80% of bifurcations were observed within 5-24 mm of the RLN. Mean diameter of the anterior branches was found to be significantly larger compared to posterior branches (1.09 ± 0.35 and 0.82 ± 0.36 mm, respectively; p < 0.01).
  
  
  CONCLUSIONS
  There is great variability in RLN branching. We observed that approximately two out of three bifurcations were unilateral and anterior branches were thicker compared to posterior branches. These findings should be taken into consideration to avoid any damage to the RLN during thyroid and parathyroid surgery.
authors.affiliation: a Sisli Hamidiye Etfal Training and Research Hospital , Sisli , Istanbul , Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Uludag
authors.affiliation: a Sisli Hamidiye Etfal Training and Research Hospital , Sisli , Istanbul , Turkey.
authors.forename: Pinar
authors.initials: P
authors.lastname: Yazici
authors.affiliation: a Sisli Hamidiye Etfal Training and Research Hospital , Sisli , Istanbul , Turkey.
authors.forename: Nurcihan
authors.initials: N
authors.lastname: Aygun
authors.affiliation: a Sisli Hamidiye Etfal Training and Research Hospital , Sisli , Istanbul , Turkey.
authors.forename: Bulent
authors.initials: B
authors.lastname: Citgez
authors.affiliation: a Sisli Hamidiye Etfal Training and Research Hospital , Sisli , Istanbul , Turkey.
authors.forename: Gurkan
authors.initials: G
authors.lastname: Yetkin
authors.affiliation: a Sisli Hamidiye Etfal Training and Research Hospital , Sisli , Istanbul , Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Mihmanli
authors.affiliation: b School of Medicine , Department of General Surgery , Bahcesehir Universitesi , Istanbul , Turkey.
authors.forename: Adnan
authors.initials: A
authors.lastname: Isgor
mesh_terms: D000328:Adult; D000368:Aged; D063405:Anatomic Variation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012009:Recurrent Laryngeal Nerve / Q000033:anatomy & histology*; D061226:Recurrent Laryngeal Nerve Injuries / Q000209:etiology; D055815:Young Adult
keywords: Neck surgery; anatomical variations; branching pattern; nerve diameter; recurrent laryngeal nerve; thyroid gland disorders