title: [Signal stability as key requirement for continuous intraoperative neuromonitoring].
abstract: BACKGROUND
  Postoperative recurrent laryngeal nerve (RLN) palsy is a well-known and dreaded complication of thyroid surgery. Continuous intraoperative neuromonitoring (CIONM) has been developed in order to provide an effective real-time surveillance of the RLN to its full extent and to detect subtle changes in nerve conductivity. A key requirement for a reliable interpretation of CIONM is signal stability.
  
  
  METHODS
  In a prospective randomized controlled pilot study 24 patients corresponding to 30 nerves at risk (NaR) were included to compare a newly developed, flexible, saxophone-shaped backstrap electrode for vagal stimulation (16 NaR) to a commercially available CE-marked cylindrical and rigid electrode (14 NaR). Electrode applicability, safety and signal stability were analyzed by assessment of electrode implantation times, stimulation currents, EMG amplitudes and electrode displacement rates.
  
  
  RESULTS
  Implantation and extraction was significantly faster and easier with the saxophone-shaped backstrap electrode. Accidental electrode displacement occurred up to eight times per operation when applying the cylindrical electrode, while a total of two displacements resulted using the backstrap electrode in this study. Stimulation currents necessary for supramaximal RLN stimulation were significantly lower using the newly developed electrode. At the same time, significantly greater stable EMG amplitudes resulted using the new saxophone-shaped electrode. No RLN palsy occurred during the study.
  
  
  CONCLUSIONS
  According to the data, only the saxophone-shaped backstrap electrode provided the signal stability required for CIONM. The closed electrode geometry with isolated contacts for nerve stimulation and defined current entry provide the prerequisites required for reliable continuous intraoperative neuromonitoring.
authors: Abteilung für Allgemein- und Visceralchirurgie mit Schwerpunkt Tumor- und minimal-invasive Chirurgie, Robert-Bosch-Krankenhaus, Stuttgart, Deutschland. wolfram.lamade@rbk.de
authors: W
authors: W
authors: Lamadé
authors: C
authors: C
authors: Ulmer
authors: C
authors: C
authors: Friedrich
authors: F
authors: F
authors: Rieber
authors: K
authors: K
authors: Schymik
authors: H M
authors: HM
authors: Gemkow
authors: K P
authors: KP
authors: Koch
authors: T
authors: T
authors: Göttsche
authors: K P
authors: KP
authors: Thon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004567:Electrodes, Implanted; D004576:Electromyography / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation*; D016105:Parathyroidectomy; D010865:Pilot Projects; D011183:Postoperative Complications / Q000503:physiopathology* / Q000517:prevention & control*; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013965:Thyroidectomy; D055536:Vagus Nerve Stimulation / Q000295:instrumentation*; D014826:Vocal Cord Paralysis / Q000175:diagnosis / Q000503:physiopathology* / Q000517:prevention & control*