title: Cryoablation of the pulmonary veins using a novel balloon catheter.
abstract: BACKGROUND
  Pulmonary vein (PV) isolation has emerged as a promising technique for the treatment of patients with drug-refractory atrial fibrillation, however, the achievement of transmural lesions has remained a challenge. We evaluated the ability of a novel balloon-based cryogenic catheter system in achieving transmural lesions for PV isolation.
  
  
  METHODS
  Six pulmonary vein ostia from three excised ovine hearts and lungs were used in this study. The balloon catheter was deployed and positioned at the ostia of the PVs and a full 8-minute ablation was then performed, while the heart was bathed in a circulating bath of normal saline at 37 degrees. Thermocouples positioned on the endocardial (balloon surface-tissue interface) and epicardial surfaces of the ostia were used to determine whether transmural freezing was achieved.
  
  
  RESULTS
  The mean temperatures measured on the endocardial and epicardial tissue in six PV ablations were -38.8 +/- 6.9 degrees C and -10.0 +/- 7.5 degrees C, respectively. The average pulmonary vein thickness was 3.3 +/- 1.4 mm.
  
  
  CONCLUSIONS
  A novel cryoablation balloon catheter is capable of achieving transmural freezing of the pulmonary vein. The catheter has promise for future clinical therapy of atrial fibrillation.
authors.affiliation: New England Medical Center, Tufts University School of Medicine, Boston, MA, USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: Garan
authors.forename: Amin
authors.initials: A
authors.lastname: Al-Ahmad
authors.forename: Teresa
authors.initials: T
authors.lastname: Mihalik
authors.forename: Catherine
authors.initials: C
authors.lastname: Cartier
authors.forename: Lea
authors.initials: L
authors.lastname: Capuano
authors.forename: David
authors.initials: D
authors.lastname: Holtan
authors.forename: Christopher
authors.initials: C
authors.lastname: Song
authors.forename: Munther K
authors.initials: MK
authors.lastname: Homoud
authors.forename: Mark S
authors.initials: MS
authors.lastname: Link
authors.forename: N A Mark
authors.initials: NA
authors.lastname: Estes
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000601:surgery*; D002404:Catheterization; D003452:Cryosurgery / Q000295:instrumentation / Q000379:methods*; D004195:Disease Models, Animal; D066298:In Vitro Techniques; D011667:Pulmonary Veins / Q000601:surgery*; D012756:Sheep