title: Ultrasound-guided permanent implantation of peripheral nerve stimulation (PNS) system for neuropathic pain of the extremities: original cases and outcomes.
abstract: OBJECTIVE
  Our objective is to describe our experience applying a minimally invasive, ultrasound-assisted technique for peripheral nerve stimulation (PNS) trial and permanent implantation in patients with neuropathic extremity pain.
  
  
  METHODS
  Retrospective case series and review of the literature. Setting. Tertiary referral center and academic medical center.
  
  
  METHODS
  Patients with upper or lower extremity neuropathic pain resistant to other therapies who responded to an ultrasound-guided peripheral nerve block at a proximal location. Interventions. Ultrasound-assisted through-the-needle placement of percutaneous neurostimulation electrodes on target major peripheral nerves for fully percutaneous trial, staged trial or permanent implantation of PNS system. A PNS trial period of 3-7 days was used.
  
  
  METHODS
  Pain relief at last follow-up, complications, therapeutic limitations due to technique as applied. Results. Six of eight (75%) patients and 7/9 (78%) peripheral nerves had a successful trial and underwent permanent PNS system implantation using a minimally invasive, ultrasound-assisted technique from November 2007 to December 2008. All but one patient with an implanted PNS system had > or =50% pain relief at last follow-up and 3/7 (43%) permanent systems were associated with > or =80% relief. Loss of paresthesia required revision to dual-lead systems in upper extremity radial nerve PNS. Infection led to explant in one case.
  
  
  CONCLUSIONS
  In a small series of patients, a minimally invasive, ultrasound-assisted technique for PNS trial, and permanent PNS implantation proved feasible. Patients without adequate analgesia during neurostimulation trial avoided surgical incision and those undergoing permanent implantation were not subjected to the potential morbidity associated with nerve dissection.
authors.affiliation: Division of Pain Medicine, Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota, USA. huntoon.marc@mayo.edu
authors.forename: Marc A
authors.initials: MA
authors.lastname: Huntoon
authors.forename: Abram H
authors.initials: AH
authors.lastname: Burgher
mesh_terms: D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted; D005121:Extremities / Q000294:innervation / Q000503:physiopathology; D006801:Humans; D008475:Median Nerve / Q000503:physiopathology / Q000601:surgery; D016343:Monitoring, Intraoperative; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods*; D010525:Peripheral Nerves / Q000503:physiopathology / Q000601:surgery; D010523:Peripheral Nervous System Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D011826:Radial Nerve / Q000503:physiopathology / Q000601:surgery; D012189:Retrospective Studies; D016896:Treatment Outcome; D014459:Ulnar Nerve / Q000503:physiopathology / Q000601:surgery; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods*