title: The feasibility and safety of applying the Magnetic Navigation System to manage chronically occluded vessels: a single centre experience.
abstract: OBJECTIVE
  Applying the Magnetic Navigation System (MNS) to manage chronic total occlusions (CTOs). The MNS precisely directs a magnetised guidewire in vivo through two permanent external magnets.
  
  
  RESULTS
  The first 43 consecutive MNS treated CTOs were retrospectively evaluated. Computed tomography coronary angiography (CTCA) co-integration with the MNS provided a virtual road map through the occlusion. Unsuccessful MNS cases were managed with bailout conventional guidewire techniques. Experienced CTO and MNS operators had unrestricted access to CTO devices and equipments. The MNS crossing success increased from 40% to 56% over 52 months and averaged 44.2% (19/43 patients). In 58.3% (14/24) of failed MNS cases the conventional wire approach was successful, giving an overall procedural success rate of 76.6%. Of those conventionally treated, two patients required pericardiocentesis. On average, 1.8 ± 0.9 stents (lengths 44.7 ± 21.4 mm and diameter 2.8 ± 0.4 mm) were implanted. Procedural times were lengthy (125.0 ± 35.3 min) requiring high fluoroscopy dosage (11980.2 ± 6457.9 Gy/cm2) and contrast media usage (388.8 ± 170.2 ml). Operators persevered less with magnetic wires (20.9 ± 12.4 min vs. 27.7 ± 24.4 min), and preferentially used the least stiff wire as first choice (53.5%). CTCA co-integration did not influence procedural outcome. As with conventional wires, higher magnetic wire successes occurred in low calcified lesions, those with a central stump and without bridging collaterals.
  
  
  CONCLUSIONS
  In unselected CTOs, the magnetic wires are safe and feasible. Current modest success rates with a high procedural bailout rate implicate the need for improved magnetic guidewire technology comparable to available sophisticated conventional CTO wires. Randomised studies are needed to clarify the value of magnetic guided recanalisation.
authors.affiliation: Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Steve
authors.initials: S
authors.lastname: Ramcharitar
authors.forename: Willem J
authors.initials: WJ
authors.lastname: van der Giessen
authors.forename: Martin
authors.initials: M
authors.lastname: van der Ent
authors.forename: Pim
authors.initials: P
authors.lastname: de Feyter
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
authors.forename: Robert-Jan
authors.initials: RJ
authors.lastname: van Geuns
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000295:instrumentation / Q000379:methods*; D057785:Catheters; D002908:Chronic Disease; D017023:Coronary Angiography / Q000379:methods; D054059:Coronary Occlusion / Q000000981:diagnostic imaging / Q000628:therapy*; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008280:Magnetics / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011857:Radiographic Image Interpretation, Computer-Assisted; D015641:Radiography, Interventional; D012189:Retrospective Studies; D013813:Therapy, Computer-Assisted / Q000295:instrumentation; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome