title: Bronchial effects of cryoballoon ablation for atrial fibrillation.
abstract: Damage to extracardiac structures, including the esophagus and phrenic nerve, is a known complication of cryoballoon ablation (CBA) during pulmonary vein (PV) isolation for atrial fibrillation (AF). Other adjacent structures, including the pulmonary bronchi and lung parenchyma, may be affected during CBA at the PV ostia.
  
  
  
  The purpose of this study was to prospectively study the bronchial effects of CBA in humans undergoing CBA for PV isolation.
  
  
  
  Ten patients undergoing CBA for AF under general anesthesia were enrolled in an institutional review board-approved prospective observational study. Real-time bronchoscopy was performed during cryoablation of PVs adjacent to pulmonary bronchi to monitor for thermal injury. Patients were followed for the development of respiratory complaints postprocedure.
  
  
  
  In 7 of 10 patients (70%) and in 13 of 22 freezes (59%), ice formation was visualized in the left mainstem bronchus during CBA in the left upper PV. Ice formation was not seen in the right mainstem bronchus during right upper PV CBA. The average time to ice formation was 89 seconds. There was no significant difference (P = -.45) in average minimum balloon temperature during freezes with ice formation (-48.5°C) and freezes without ice formation (-46.3°C). No patients went on to develop respiratory complications.
  
  
  
  Unrecognized ice formation occurs frequently in the left mainstem bronchus during CBA for AF. This information helps explain the source of cough and hemoptysis in some patients who undergo CBA. The long-term consequences of this novel finding and the implications for procedural safety are unknown.
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois. Electronic address: Nishant-Verma@northwestern.edu.
authors.forename: Nishant
authors.initials: N
authors.lastname: Verma
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Colin T
authors.initials: CT
authors.lastname: Gillespie
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: A Christine
authors.initials: AC
authors.lastname: Argento
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Todd
authors.initials: T
authors.lastname: Tomson
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Dandamudi
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Paloma
authors.initials: P
authors.lastname: Piña
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Sukit
authors.initials: S
authors.lastname: Ringwala
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Albert C
authors.initials: AC
authors.lastname: Lin
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Alexandru B
authors.initials: AB
authors.lastname: Chicos
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Susan
authors.initials: S
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Rishi
authors.initials: R
authors.lastname: Arora
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Rod S
authors.initials: RS
authors.lastname: Passman
authors.affiliation: Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Bradley P
authors.initials: BP
authors.lastname: Knight
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000601:surgery*; D001999:Bronchoscopy / Q000379:methods; D006328:Cardiac Catheterization / Q000379:methods; D015331:Cohort Studies; D003452:Cryosurgery / Q000009:adverse effects / Q000379:methods*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D005471:Fluoroscopy / Q000379:methods; D006801:Humans; D007431:Intraoperative Complications / Q000453:epidemiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D011379:Prognosis; D011446:Prospective Studies; D020127:Recovery of Function; D018570:Risk Assessment; D016896:Treatment Outcome
keywords: AF ablation; Atrial fibrillation; Bronchoscopy; Cryoablation; PV isolation