title: Relationship of vocal cord paralysis to the coil diameter of vagus nerve stimulator leads.
abstract: OBJECTIVE
  This investigation was done to examine, following implantation of vagus nerve stimulators, the relationship of vocal cord paralysis to the inner diameter of the coils used to attach the stimulator lead to the nerve.
  
  
  METHODS
  All data in this investigation were collected, as mandated by the FDA, by the manufacturer of vagus nerve stimulators and were made available without restrictions for analysis by the authors. The data reflect all initial device implantations in the United States for the period from 1997 through 2012.
  
  
  RESULTS
  Vocal cord paralysis was reported in 193 of 51,882 implantations. In patients aged 18 years and older, the incidence of paralysis was 0.26% when the stimulator leads had coil diameters of 3 mm and 0.51% when the leads had 2-mm-diameter coils (p < 0.05). Across all age groups, the incidence of vocal cord paralysis increased with age at implantation for leads having 2-mm-diameter coils.
  
  
  CONCLUSIONS
  In patients aged 18 years and older, vocal cord paralysis occurred at almost twice the rate with the implantation of vagus nerve stimulator leads having 2-mm-diameter coils than with leads having 3-mm-diameter coils. The incidence of vocal cord paralysis increases with patient age at implantation.
authors.affiliation: Department of Neurosurgery, University of Colorado School of Medicine, Aurora;
authors.forename: Leslie C
authors.initials: LC
authors.lastname: Robinson
authors.forename: Ken R
authors.initials: KR
authors.lastname: Winston
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004567:Electrodes, Implanted / Q000009:adverse effects*; D004827:Epilepsy / Q000150:complications / Q000628:therapy; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055536:Vagus Nerve Stimulation / Q000009:adverse effects* / Q000295:instrumentation*; D014826:Vocal Cord Paralysis / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult
keywords: VNS = vagus nerve stimulation; complications; epilepsy; vagus nerve injury; vagus nerve stimulator lead; vocal cord paralysis