title: The current state of intermittent intraoperative neural monitoring for prevention of recurrent laryngeal nerve injury during thyroidectomy: a PRISMA-compliant systematic review of overlapping meta-analyses.
abstract: OBJECTIVE
  Recurrent laryngeal nerve (RLN) injury is one of the most common and detrimental complications following thyroidectomy. Intermittent intraoperative nerve monitoring (I-IONM) has been proposed to reduce prevalence of RLN injury following thyroidectomy and has gained increasing acceptance in recent years.
  
  
  METHODS
  A comprehensive database search was performed, and data from eligible meta-analyses meeting the inclusion criteria were extracted. Transient, permanent, and overall RLN injuries were the primary outcome measures. Quality assessment via AMSTAR, heterogeneity appraisal, and selection of best evidence was performed via a Jadad algorithm.
  
  
  RESULTS
  Eight meta-analyses met the inclusion criteria. Meta-analyses included between 6 and 23 original studies each. Via utilization of the Jadad algorithm, the selection of best evidence resulted in choosing of Pisanu et al. (Surg Res 188:152-161, 2014). Five out of eight meta-analyses demonstrated non-significant (p > 0.05) RLN injury reduction with the use of I-IONM versus nerve visualization alone.
  
  
  CONCLUSIONS
  To date, I-IONM has not achieved a significant level of RLN injury reduction as shown by the meta-analysis conducted by Pisanu et al. (Surg Res 188:152-161, 2014). However, most recent developments of IONM technology including continuous vagal IONM and concept of staged thyroidectomy in case of loss of signal on the first side in order to prevent bilateral RLN injury may provide additional benefits which were out of the scope of this study and need to be assessed in further prospective multicenter trials.
authors.affiliation: International Evidence-Based Anatomy Working Group, 12 Kopernika St, 31-034, Krakow, Poland. bmhenry55@gmail.com.|Department of Anatomy, Jagiellonian University Medical College, 12 Kopernika St, 31-034, Krakow, Poland. bmhenry55@gmail.com.
authors.forename: Brandon Michael
authors.initials: BM
authors.lastname: Henry
authors.affiliation: International Evidence-Based Anatomy Working Group, 12 Kopernika St, 31-034, Krakow, Poland.|Department of Anatomy, Jagiellonian University Medical College, 12 Kopernika St, 31-034, Krakow, Poland.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Graves
authors.affiliation: International Evidence-Based Anatomy Working Group, 12 Kopernika St, 31-034, Krakow, Poland.|Department of Anatomy, Jagiellonian University Medical College, 12 Kopernika St, 31-034, Krakow, Poland.|Division of Medicine, Stavanger University Hospital, Gerd-Ragna Bloch Thorsens gate 8, 4011, Stavanger, Norway.
authors.forename: Jens
authors.initials: J
authors.lastname: Vikse
authors.affiliation: Faculty of Medicine and Surgery, University of Cagliari, S.S. 554, Bivio Sestu, 09042, Monserrato, CA, Sardinia, Italy.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Sanna
authors.affiliation: International Evidence-Based Anatomy Working Group, 12 Kopernika St, 31-034, Krakow, Poland.|Department of Anatomy, Jagiellonian University Medical College, 12 Kopernika St, 31-034, Krakow, Poland.
authors.forename: Przemysław A
authors.initials: PA
authors.lastname: Pękala
authors.affiliation: International Evidence-Based Anatomy Working Group, 12 Kopernika St, 31-034, Krakow, Poland.|Department of Anatomy, Jagiellonian University Medical College, 12 Kopernika St, 31-034, Krakow, Poland.
authors.forename: Jerzy A
authors.initials: JA
authors.lastname: Walocha
authors.affiliation: Department of Endocrine Surgery, Third Chair of General Surgery, Jagiellonian University Medical College, 35-37 Pradnicka St, 31-202, Krakow, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Barczyński
authors.affiliation: International Evidence-Based Anatomy Working Group, 12 Kopernika St, 31-034, Krakow, Poland.|Department of Anatomy, Jagiellonian University Medical College, 12 Kopernika St, 31-034, Krakow, Poland.
authors.forename: Krzysztof A
authors.initials: KA
authors.lastname: Tomaszewski
mesh_terms: D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology / Q000517:prevention & control*; D064795:Intraoperative Neurophysiological Monitoring; D011183:Postoperative Complications / Q000209:etiology / Q000517:prevention & control*; D061226:Recurrent Laryngeal Nerve Injuries / Q000209:etiology / Q000517:prevention & control*; D013965:Thyroidectomy / Q000009:adverse effects*; D014826:Vocal Cord Paralysis / Q000209:etiology / Q000517:prevention & control*
keywords: Iatrogenic injury; Intermittent intraoperative nerve monitoring; Recurrent laryngeal nerve; Thyroidectomy; Vocal fold paresis