title: Simplified method for esophagus protection during radiofrequency catheter ablation of atrial fibrillation--prospective study of 704 cases.
abstract: BACKGROUND
  Although rare, the atrioesophageal fistula is one of the most feared complications in radiofrequency catheter ablation of atrial fibrillation due to the high risk of mortality.
  
  
  OBJECTIVE
  This is a prospective controlled study, performed during regular radiofrequency catheter ablation of atrial fibrillation, to test whether esophageal displacement by handling the transesophageal echocardiography transducer could be used for esophageal protection.
  
  
  METHODS
  Seven hundred and four patients (158 F/546M [22.4%/77.6%]; 52.8 ± 14 [17-84] years old), with mean EF of 0.66 ± 0.8 and drug-refractory atrial fibrillation were submitted to hybrid radiofrequency catheter ablation (conventional pulmonary vein isolation plus AF-Nests and background tachycardia ablation) with displacement of the esophagus as far as possible from the radiofrequency target by transesophageal echocardiography transducer handling. The esophageal luminal temperature was monitored without and with displacement in 25 patients.
  
  
  RESULTS
  The mean esophageal displacement was 4 to 9.1cm (5.9 ± 0.8 cm). In 680 of the 704 patients (96.6%), it was enough to allow complete and safe radiofrequency delivery (30W/40ºC/irrigated catheter or 50W/60ºC/8 mm catheter) without esophagus overlapping. The mean esophageal luminal temperature changes with versus without esophageal displacement were 0.11 ± 0.13ºC versus 1.1 ± 0.4ºC respectively, P<0.01. The radiofrequency had to be halted in 68% of the patients without esophageal displacement because of esophageal luminal temperature increase. There was no incidence of atrioesophageal fistula suspected or confirmed. Only two superficial bleeding caused by transesophageal echocardiography transducer insertion were observed.
  
  
  CONCLUSIONS
  Mechanical esophageal displacement by transesophageal echocardiography transducer during radiofrequency catheter ablation was able to prevent a rise in esophageal luminal temperature, helping to avoid esophageal thermal lesion. In most cases, the esophageal displacement was sufficient to allow safe radiofrequency application without esophagus overlapping, being a convenient alternative in reducing the risk of atrioesophageal fistula.
authors.affiliation: São Paulo Cardiology Institute, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: José Carlos Pachón
authors.initials: JC
authors.lastname: Mateos
authors.affiliation: Cardiology Institute of São Paulo Heart Hospital Dante Pazzanese, São Paulo, SP, Brazil.
authors.forename: Enrique I Pachón
authors.initials: EI
authors.lastname: Mateos
authors.affiliation: São Paulo Heart Hospital, São Paulo, SP, Brazil.
authors.forename: Tomas G Santillana
authors.initials: TG
authors.lastname: Peña
authors.affiliation: São Paulo Heart Hospital, São Paulo, SP, Brazil.
authors.forename: Tasso Julio
authors.initials: TJ
authors.lastname: Lobo
authors.affiliation: São Paulo Cardiology Institute, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Juán Carlos Pachón
authors.initials: JC
authors.lastname: Mateos
authors.affiliation: São Paulo Cardiology Institute, São Paulo, SP, Brazil.
authors.forename: Remy Nelson A
authors.initials: RN
authors.lastname: Vargas
authors.affiliation: São Paulo Heart Hospital, São Paulo, SP, Brazil.
authors.forename: Carlos Thiene C
authors.initials: CT
authors.lastname: Pachón
authors.affiliation: São Paulo Heart Hospital, São Paulo, SP, Brazil.
authors.forename: Juán Carlos Zerpa
authors.initials: JC
authors.lastname: Acosta
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000601:surgery*; D009202:Cardiomyopathies / Q000209:etiology / Q000517:prevention & control*; D017115:Catheter Ablation / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000295:instrumentation; D004937:Esophageal Fistula / Q000209:etiology / Q000517:prevention & control*; D004947:Esophagus / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000293:injuries; D005260:Female; D005402:Fistula / Q000209:etiology / Q000517:prevention & control*; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D013696:Temperature; D016896:Treatment Outcome; D055815:Young Adult