title: Ovine tests of a novel spinal cord neuromodulator and dentate ligament fixation method.
abstract: BACKGROUND
  To improve methods for the treatment of intractable pain, we are developing a novel intradural spinal cord stimulator that could be either attached to the dentate ligaments of the human spinal cord or fitted around the dorsal arc of the cord itself.
  
  
  OBJECTIVE
  Our goal was to carry out the first in vivo tests of these attachment methods in an ovine model using custom-built devices and instrumentation. For eventual translational studies, we also explored methods of mimicking a human dentate ligament attachment technique in this large animal model.
  
  
  METHODS
  As a starting point, we investigated details of the gross and histological anatomy of the ovine denticulate ligaments, and compared them with their human counterpart. The gap between the dura and the spinal cord in the sheep is small; hence, the denticulate ligaments are not long enough to accommodate human-scaled attachment clips. Therefore, lateral strips of the spinal-canal dura were fashioned to serve this same device attachment function.
  
  
  RESULTS
  This form of dural anchoring was implemented surgically for fixation of a silicone membrane implant that had 12 electrodes, and somatosensory evoked potentials were obtained successfully when stimuli were applied to it. The dorsal arc clamping technique was also implemented.
  
  
  CONCLUSIONS
  We demonstrated that the dural attachment method is an effective surrogate model for testing the human dentate ligament device fixation technique, and that this mode of fixation was preferable to dorsal arc attachment. The relevant surgical innovations, anatomical findings, and the preliminary electrophysiological data from a pial surface stimulator attached in this way are presented.
authors.affiliation: Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA.
authors.forename: Katherine N
authors.initials: KN
authors.lastname: Gibson-Corley
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Oya
authors.forename: Oliver
authors.initials: O
authors.lastname: Flouty
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Fredericks
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Jeffery
authors.forename: George T
authors.initials: GT
authors.lastname: Gillies
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Howard
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004388:Dura Mater / Q000502:physiology*; D004566:Electrodes; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D008022:Ligaments / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000502:physiology*; D010148:Intractable Pain / Q000628:therapy; D010841:Pia Mater / Q000502:physiology; D012756:Sheep; D013116:Spinal Cord / Q000502:physiology*; D062187:Spinal Cord Stimulation / Q000379:methods*
chemical_list: D018377:Neurotransmitter Agents