title: Magnetic versus manual guidewire manipulation in neuroradiology: in vitro results.
abstract: BACKGROUND
  Standard microguidewires used in interventional neuroradiology have a predefined shape of the tip that cannot be changed while the guidewire is in the vessel. We evaluated a novel magnetic navigation system (MNS) that generates a magnetic field to control the deflection of a microguidewire that can be used to reshape the guidewire tip in vivo without removing the wire from the body, thereby potentially facilitating navigation along tortuous paths or multiple acute curves.
  
  
  METHODS
  The MNS consists of two permanent magnets positioned on either side of the fluoroscopy table that create a constant precisely controlled magnetic field in the defined region of interest. This field enables omnidirectional rotation of a 0.014-inch magnetic microguidewire (MG). Speed of navigation, accuracy in a tortuous vessel anatomy and the potential for navigating into in vitro aneurysms were tested by four investigators with differing experience in neurointervention and compared to navigation with a standard, manually controlled microguidewire (SG).
  
  
  RESULTS
  Navigation using MG was faster (P=0.0056) and more accurate (0.2 mistakes per trial vs. 2.6 mistakes per trial) only in less-experienced investigators. There were no statistically significant differences between the MG and the SG in the hands of experienced investigators. One aneurysm with an acute angulation from the carrier vessel could be navigated only with the MG while the SG failed, even after multiple reshaping manoeuvres.
  
  
  CONCLUSIONS
  Our findings suggest that magnetic navigation seems to be easier, more accurate and faster in the hands of less-experienced investigators. We consider that the features of the MNS may improve the efficacy and safety of challenging neurointerventional procedures.
authors.affiliation: Department of Neuroradiology, University Hospital Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany. tkrings@izkf.rwth-aachen.de
authors.forename: T
authors.initials: T
authors.lastname: Krings
authors.forename: J
authors.initials: J
authors.lastname: Finney
authors.forename: P
authors.initials: P
authors.lastname: Niggemann
authors.forename: P
authors.initials: P
authors.lastname: Reinacher
authors.forename: N
authors.initials: N
authors.lastname: Lück
authors.forename: A
authors.initials: A
authors.lastname: Drexler
authors.forename: J
authors.initials: J
authors.lastname: Lovell
authors.forename: A
authors.initials: A
authors.lastname: Meyer
authors.forename: R
authors.initials: R
authors.lastname: Sehra
authors.forename: P
authors.initials: P
authors.lastname: Schauerte
authors.forename: M
authors.initials: M
authors.lastname: Reinges
authors.forename: F J
authors.initials: FJ
authors.lastname: Hans
authors.forename: A
authors.initials: A
authors.lastname: Thron
mesh_terms: D002404:Catheterization; D002983:Clinical Competence; D005471:Fluoroscopy; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging*; D008280:Magnetics; D008955:Models, Cardiovascular; D038361:Neuronavigation / Q000379:methods*; D019047:Phantoms, Imaging; D014102:Torsion Abnormality