title: Feasibility of ultrasound-guided percutaneous placement of peripheral nerve stimulation electrodes and anchoring during simulated movement: part two, upper extremity.
abstract: OBJECTIVE
  Peripheral nerve stimulation (PNS) may provide analgesia for neuropathic pain syndromes in that nerve distribution. PNS electrode placement using ultrasound (US) guidance for upper extremity pain syndromes has not been reported. Existing anchoring technology may allow permanent implantation without significant migration.
  
  
  METHODS
  Three cadaver midhumeral fresh frozen upper extremity specimens were studied. US scanning was performed, targeting electrode placement at the radial, ulnar, and median nerves. Leads were anchored in the superficial fascia. The targeted nerves were exposed by careful dissection. Visual inspection for gross nerve damage, and electrode proximity to the nerve was performed. After confirmation of adequate lead placement, 2 extremities were sutured and placed in a continuous passive motion (CPM) machine for 21 hours to simulate activity. Each electrode was assessed for migration.
  
  
  RESULTS
  Acceptable locations for US-guided electrode placement were: radial nerve approximately 10-14 cm superior to the lateral epicondyle; median nerve approximately 6 cm below the antecubital fossa; and ulnar nerve approximately 9 to 13 cm above the medial epicondyle. One electrode was placed at each site without difficulty. After careful exposure, visual inspection showed no gross nerve damage. Each electrode had at least 2 electrical contacts within 2 mm of the nerve sheath. At CPM termination, only the median nerve electrode on 1 cadaver extremity had migrated significantly.
  
  
  CONCLUSIONS
  This new minimally invasive approach to lead placement requires further study to determine implantation criteria, optimal locations, anchoring techniques, and electrode design to define best clinical practice.
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905, USA. huntoon.marc@mayo.edu
authors.forename: Marc A
authors.initials: MA
authors.lastname: Huntoon
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Hoelzer
authors.forename: Abram H
authors.initials: AH
authors.lastname: Burgher
authors.forename: Mark Friedrich B
authors.initials: MF
authors.lastname: Hurdle
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Huntoon
mesh_terms: D002102:Cadaver; D004566:Electrodes; D005240:Feasibility Studies; D006801:Humans; D008475:Median Nerve / Q000000981:diagnostic imaging*; D009437:Neuralgia / Q000628:therapy*; D011826:Radial Nerve / Q000000981:diagnostic imaging*; D004561:Transcutaneous Electric Nerve Stimulation / Q000295:instrumentation* / Q000379:methods; D014459:Ulnar Nerve / Q000000981:diagnostic imaging*; D018084:Ultrasonography, Interventional; D034941:Upper Extremity / Q000000981:diagnostic imaging / Q000294:innervation*