title: A randomized comparison of transseptal and transaortic approaches for magnetically guided ablation of left-sided accessory pathways.
abstract: OBJECTIVE
  Radiofrequency catheter ablation of left-sided accessory pathways (APs) can be performed either by a transseptal (TS) or transaortic (TA) approach. When performed manually, these techniques are equally effective. The aim of this prospective randomized study was to compare these approaches using a magnetic navigation system (MNS) (Niobe, Stereotaxis, St. Louis, MO, USA).
  
  
  METHODS
  Twenty-two consecutive patients were randomized to undergo ablation of a left-sided AP by either a TS or a TA approach. The MNS was used in all patients for catheter navigation and eventual ablation, after electrophysiology study (EPS) confirmed the presence of left-sided APs. Crossover was allowed after failure of the initial approach. Success rates, procedure, fluoroscopy, and ablation times were compared.
  
  
  RESULTS
  Of 11 procedures, 10 (91%) were successful in the TS group. The patient crossed over to the TA approach remained unsuccessful. Successful elimination of the AP was obtained in nine (82%) of 11 of the TA procedures. Of the two patients who crossed over to a TS procedure in the same session, one was successful and one remained unsuccessful. Total procedure time did not differ in both groups (87.1 ± 30.8 vs 90.9 ± 26.5 minutes). When total procedure and patient fluoroscopy times were divided into EPS time, time to first application, to successful application, and time to perform TS puncture or to retrogradely cross the aortic valve, only the last measurement differed significantly for both groups (P < 0.01). Ablation times were comparable in both groups. No major complications occurred.
  
  
  CONCLUSIONS
  Our data show that TS and TA approaches are equal in success rate and total procedure, patient fluoroscopy, and ablation time when using the MNS for left-sided AP ablation. However, crossing the aortic valve with the MNS is faster than completing a TS puncture.
authors.affiliation: Department of Cardiology, Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands. b.schwagten@erasmusmc.nl
authors.forename: Bruno
authors.initials: B
authors.lastname: Schwagten
authors.forename: Luc
authors.initials: L
authors.lastname: Jordaens
authors.forename: Maximo
authors.initials: M
authors.lastname: Rivero-Ayerza
authors.forename: Yves
authors.initials: Y
authors.lastname: Van Belle
authors.forename: Paul
authors.initials: P
authors.lastname: Knops
authors.forename: Ing Andrew
authors.initials: IA
authors.lastname: Thornton
authors.forename: Tamas
authors.initials: T
authors.lastname: Szili-Torok
mesh_terms: D058606:Accessory Atrioventricular Bundle / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D016896:Treatment Outcome