title: Does extralaryngeal branching have an impact on the rate of postoperative transient or permanent recurrent laryngeal nerve palsy?
abstract: BACKGROUND
  This prospective study assessed the prevalence of the extralaryngeal branching of the recurrent laryngeal nerve (RLN) and its impact on the incidence of postoperative transient or permanent RLN palsy.
  
  
  METHODS
  Total or hemithyroidectomy was performed in 115 patients, with a total of 195 RLNs displayed. The RLN extralaryngeal branches were routinely identified and preserved. The postoperative course of each patient was evaluated. Outcomes of patients with and without branching RLN were compared.
  
  
  RESULTS
  In all, 36 of 195 (18.5%) nerves showed extralaryngeal branching: 27 cases (25.5%) on the right and 9 on the left side (10.1%; p = 0.0088).Trifurcation of the RLN was identified in two dissections (1%). Bilateral bifurcations were observed in 3 of 80 (3.7%) patients. We reported four (2.1%) unilateral permanent RLN palsies, eight cases of unilateral transient nerve palsy (4.1%), and one bilateral transient RLN injury (0.6%). The comparative analysis of postoperative outcomes between branched and nonbranched RLNs revealed that the anatomical variation was more frequently associated both with unilateral permanent RLN palsy (relative risk, 13.25; 95% confidence interval, 1.42-123.73; p = 0.0204) and unilateral transient RLN palsy (relative risk, 7.36; 95% confidence interval, 1.84-29.4; p = 0.0061). The only case of bilateral transient RLN injury was associated with a nonrecurrent inferior laryngeal nerve.
  
  
  CONCLUSIONS
  Branched RLNs represent a risk factor both for transient and permanent nerve palsy after surgery. Awareness of this anatomical variation and its routine investigation are essential during thyroid surgery to limit its relevant impact on postoperative RLN injury rate.
authors.affiliation: Department of General Surgery, University of Brescia School of Medicine, Brescia , Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Casella
authors.forename: Giacomo
authors.initials: G
authors.lastname: Pata
authors.forename: Riccardo
authors.initials: R
authors.lastname: Nascimbeni
authors.forename: Francesco
authors.initials: F
authors.lastname: Mittempergher
authors.forename: Bruno
authors.initials: B
authors.lastname: Salerni
mesh_terms: D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012009:Recurrent Laryngeal Nerve / Q000033:anatomy & histology*; D013965:Thyroidectomy / Q000379:methods*; D016896:Treatment Outcome; D014826:Vocal Cord Paralysis / Q000601:surgery*