title: Visually-guided balloon catheter ablation of atrial fibrillation: experimental feasibility and first-in-human multicenter clinical outcome.
abstract: BACKGROUND
  Electric isolation of the pulmonary veins (PVs) can successfully treat patients with paroxysmal atrial fibrillation. However, it remains technically challenging to identify the left atrial-PV junction and sequentially position the ablation catheter in a point-by-point contiguous fashion to isolate the PVs. In this study, a novel endoscopic ablation system was used to directly visualize and ablate tissue at the left atrial-PV junction with laser energy.
  
  
  RESULTS
  This study consisted of 2 phases: a short-term (n=9) and long-term (n=11) canine experimental validation phase and a multicenter clinical feasibility phase (n=30 paroxysmal atrial fibrillation patients). After transseptal puncture, the balloon-based endoscopic ablation system was advanced to each PV ostium, and arcs of laser energy (90 degrees to 360 degrees ) were projected onto the target left atrial-PV junction. Electric PV isolation was defined with a circular multielectrode catheter. In the short-term preclinical experimental phase, 15 of 17 targeted PVs (88%) were successfully isolated. Pathological examination revealed well-demarcated circumferential lesions with minimal endothelial disruption. In the long-term experiments, 9 of 10 targeted veins (90%) remained persistently isolated (at 4 to 8 weeks). In the clinical phase, 105 of 116 PVs (91%) were successfully isolated. After a single procedure, the 12-month drug-free rate of freedom from atrial fibrillation was 60% (18 of 30 patients). There were no significant PV stenoses, but adverse events included 1 episode of cardiac tamponade, 1 stroke without residual defect, and 1 asymptomatic phrenic nerve palsy.
  
  
  CONCLUSIONS
  This study establishes the feasibility of a novel paradigm for AF ablation: direct visualization to guide catheter ablation of the left atrial-PV junction.
authors: Mount Sinai School of Medicine, New York, USA. vreddy@med.miami.edu
authors: Vivek Y
authors: VY
authors: Reddy
authors: Petr
authors: P
authors: Neuzil
authors: Sakis
authors: S
authors: Themistoclakis
authors: Stephan B
authors: SB
authors: Danik
authors: Aldo
authors: A
authors: Bonso
authors: Antonio
authors: A
authors: Rossillo
authors: Antonio
authors: A
authors: Raviele
authors: Robert
authors: R
authors: Schweikert
authors: Sabine
authors: S
authors: Ernst
authors: Karl-Heinz
authors: KH
authors: Kuck
authors: Andrea
authors: A
authors: Natale
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001281:Atrial Fibrillation / Q000628:therapy*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D004285:Dogs; D004724:Endoscopy / Q000009:adverse effects / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006325:Heart Atria / Q000601:surgery; D006801:Humans; D007834:Lasers; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000601:surgery*; D016896:Treatment Outcome