title: New backstrap vagus electrode for continuous intraoperative neuromonitoring in thyroid surgery.
abstract: BACKGROUND
  Continuous intraoperative neuromonitoring (CIONM) via vagal nerve stimulation allows real-time surveillance of the recurrent laryngeal nerve during thyroid surgery. However, for effective CIONM, subtle changes in recurrent laryngeal nerve conductivity have to be detected. A newly developed stimulation electrode that provides stable nerve stimulation and safe application is presented.
  
  
  METHODS
  For electrode validation, current distribution was simulated with the finite element method. Mechanical characteristics were assessed through bench testing. Clinical evaluation was initiated with 11 thyroid surgeries.
  
  
  RESULTS
  Experimental and clinical results led to the development of a tripolar gold/polyimide electrode mounted onto a backstrap-shaped silicone body. It facilitated rapid electrode implantation and extraction (median implantation time 4 ± 19 seconds). Peak extraction force was 570 mN. Median supramaximal stimulation currents were 2.00 ± 0.95 mA and resulted in reliable electromyogram responses (median 3.1 ± 3.0 mV). No intraoperative electrode dislocations occurred, and no postoperative nerve palsy was observed.
  
  
  CONCLUSIONS
  The new backstrap vagal stimulation electrode meets the requirements for reliable CIONM.
authors: Department of General and Visceral Surgery, Robert-Bosch Hospital, Stuttgart, Germany. wolfram.lamade@rbk.de
authors: Wolfram
authors: W
authors: Lamadé
authors: Christoph
authors: C
authors: Ulmer
authors: Fabian
authors: F
authors: Rieber
authors: Colin
authors: C
authors: Friedrich
authors: Klaus P
authors: KP
authors: Koch
authors: Klaus-Peter
authors: KP
authors: Thon
mesh_terms: D004558:Electric Stimulation / Q000295:instrumentation*; D004566:Electrodes; D004576:Electromyography; D004867:Equipment Design; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D016343:Monitoring, Intraoperative / Q000295:instrumentation*; D012009:Recurrent Laryngeal Nerve / Q000502:physiology*; D013959:Thyroid Diseases / Q000503:physiopathology / Q000601:surgery*; D014630:Vagus Nerve / Q000502:physiology*