title: Prospective study of vocal fold function after loss of the neuromonitoring signal in thyroid surgery: The International Neural Monitoring Study Group's POLT study.
abstract: Intraoperative neuromonitoring identifies recurrent laryngeal nerve (RLN) injury and gives prognostic information regarding postoperative glottic function. Loss of the neuromonitoring signal (LOS) signifies segmental type 1 or global type 2 RLN injury. This study aimed at identifying risk factors for RLN injury and determining vocal fold (VF) function initially and 6 months after definitive LOS.
  
  
  
  Prospective study encompassing 21 hospitals from 13 countries.
  
  
  
  Included in this study were patients with persistent intraoperative LOS.
  
  
  
  At first postoperative laryngoscopy, early VF palsy was present in 94 of all 115 patients with LOS (81.7%): in 53 of 56 patients (94.6%) with type 1 injury and 41 of 59 patients (69.5%) with type 2 injury. In LOS type 1, women outnumbered men >5-fold. Traction produced LOS type 1 in 38 of 56 patients (67.9%) and LOS type 2 in 54 of 59 patients (91.5%). Course of the RLN posterior and/or anterior to the inferior thyroid artery, extralaryngeal branching, or tuberculum of Zuckerkandl did not increase VF palsy rates. Permanent VF palsy rates were also lower (P = .661) after LOS type 2 than after LOS type 1: 6.8% (four of 59 patients) versus 10.7% (six of 56 patients). Intraoperative administration of steroids did not diminish postoperative VF palsy rates.
  
  
  
  LOS type 1 entails more severe nerve damage than LOS type 2, affecting women disproportionately. Both LOS types, being primarily associated with traction injury, are unaffected by variant neck anatomy in expert hands and unresponsive to steroids.
  
  
  
  2b Laryngoscope, 126:1260-1266, 2016.
authors.affiliation: Department of General, Visceral, and Vascular Surgery, University Hospital of Martin Luther University, Halle (Saale), Germany.
authors.forename: Rick
authors.initials: R
authors.lastname: Schneider
authors.affiliation: Division of Thyroid and Parathyroid Surgery, Harvard Medical School, Boston, Massachusetts, U.S.A.
authors.forename: Gregory
authors.initials: G
authors.lastname: Randolph
authors.affiliation: Department for Endocrine Surgery, University of Insubria, Varese, Italy.
authors.forename: Gianlorenzo
authors.initials: G
authors.lastname: Dionigi
authors.affiliation: Department of Endocrine Surgery, 3rd Chair of General Surgery, Jagiellonian University, Krakow, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Barczyński
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Medical University, Kaohsiung City, Taiwan.
authors.forename: Feng-Yu
authors.initials: FY
authors.lastname: Chiang
authors.affiliation: Thoracic and Endocrine Surgery, University Hospitals of Geneva, Geneva, Switzerland.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Triponez
authors.affiliation: Department of Endocrine Surgery, Central Clinic of Athens, Athens, Greece.
authors.forename: Kyriakos
authors.initials: K
authors.lastname: Vamvakidis
authors.affiliation: Department of Surgery, Haukeland University Hospital, Bergen, Norway.
authors.forename: Katrin
authors.initials: K
authors.lastname: Brauckhoff
authors.affiliation: Endocrine Surgery Section, Clinic of General, Visceral, and Transplantation Surgery, University Medical Center, Mainz, Germany.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Musholt
authors.affiliation: Department of Surgery, Lund University Hospital, Lund, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Almquist
authors.affiliation: Department of General Surgery, University of Catanzaro, Catanzaro, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Innaro
authors.affiliation: Department of Surgery, University Hospital "Virgen Macarena", Seville, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Jimenez-Garcia
authors.affiliation: Department of Endocrine Surgery, University Hospital of Poitiers, Poitiers, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Kraimps
authors.affiliation: Department of Surgery, Kuma Hospital, Kobe, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Miyauchi
authors.affiliation: Department of General, Gastroenterological and Endocrine Surgery, Medical University Wrocław, Wrocław, Poland.
authors.forename: Beata
authors.initials: B
authors.lastname: Wojtczak
authors.affiliation: Department of Endocrine Surgery, University Hospital of Poitiers, Poitiers, France.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Donatini
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, University of Brescia, Brescia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Lombardi
authors.affiliation: Department of General, Viszeral and Thoracic Surgery, Bundeswehr Hospital, Berlin, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Müller
authors.affiliation: Thyroid and Parathyroid Surgery Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori, Fondazione G. Pascale, Naples, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Pezzullo
authors.affiliation: Department of General Surgery, "Principe de Asturias" University Hospital, Madrid, Spain.
authors.forename: Tomas
authors.initials: T
authors.lastname: Ratia
authors.affiliation: Department of General and Endocrine Surgery, OLV Clinic Aalst, Aalst, Belgium.
authors.forename: Sam
authors.initials: S
authors.lastname: Van Slycke
authors.affiliation: Department of General, Visceral, and Vascular Surgery, University Hospital of Martin Luther University, Halle (Saale), Germany.
authors.forename: Phuong
authors.initials: P
authors.lastname: Nguyen Thanh
authors.affiliation: Department of General, Visceral, and Vascular Surgery, University Hospital of Martin Luther University, Halle (Saale), Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Lorenz
authors.affiliation: Department of General, Visceral, and Vascular Surgery, University Hospital of Martin Luther University, Halle (Saale), Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Sekulla
authors.affiliation: Department of General, Visceral, and Vascular Surgery, University Hospital of Martin Luther University, Halle (Saale), Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Machens
authors.affiliation: Department of General, Visceral, and Vascular Surgery, University Hospital of Martin Luther University, Halle (Saale), Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Dralle
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011184:Postoperative Period; D011379:Prognosis; D011446:Prospective Studies; D061226:Recurrent Laryngeal Nerve Injuries / Q000175:diagnosis*; D012307:Risk Factors; D013959:Thyroid Diseases / Q000601:surgery; D013961:Thyroid Gland / Q000601:surgery*; D013965:Thyroidectomy / Q000009:adverse effects* / Q000379:methods; D014827:Vocal Cords / Q000293:injuries / Q000294:innervation / Q000502:physiology*
keywords: Intraoperative neuromonitoring; loss of signal; recurrent laryngeal nerve injury; transient and permanent vocal fold palsy