title: Spinal cord stimulator explantation for magnetic resonance imaging: a case series.
abstract: BACKGROUND
  Spinal cord stimulator (SCS) systems are implanted to treat pain conditions such as neuropathic, radicular, and ischemic pain syndromes. Prior to July 2013, SCS systems were not magnetic resonance imaging (MRI) compatible due to the risk of thermal injury at the site of the leads and generator. Although there are some case reports of patients undergoing MRI studies with SCS systems in place, these stimulators are frequently explanted when clinical care has necessitated an MRI. The purpose of this case series is to discuss the role of SCS explantation in order to acquire an MRI.
  
  
  METHODS
  This study was performed at a tertiary academic pain medicine clinic. After exempt status was obtained via the institutional review board, patients were identified via the use of Common Procedural Terminology codes for implantable devices. A chart review was performed to identify all patients >18 years of age who had a lumbar or thoracic dorsal column SCS implanted during January 2001-December 2011. The charts were then followed to identify any patients who underwent a surgery for explantation of the device. Data collection included the total number of patients undergoing permanent SCS implantation, the total number of explantation of these devices, patient demographic factors, indication for SCS implantation, incidence of revisions and the indication, duration between implantation and explant of the device, and indication for explantation.
  
  
  RESULTS
  During the time between 2001 and 2011, 199 patients were identified who underwent a thoracic or lumbar SCS implant after a successful trial. Among 199 implants, 33 devices were explanted, and of these, four were explanted due to the primary need for an MRI scan.
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Moeschler
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Sanders
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: W Michael
authors.initials: WM
authors.lastname: Hooten
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Hoelzer
mesh_terms: D000328:Adult; D000368:Aged; D059350:Chronic Pain / Q000628:therapy*; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018710:Pain Clinics; D013116:Spinal Cord / Q000502:physiology*; D062187:Spinal Cord Stimulation / Q000379:methods*; D055815:Young Adult
keywords: Case series; MRI; contraindications; spinal cord stimulation; stimulation