title: Feasibility and safety of using an esophageal protective system to eliminate esophageal thermal injury: implications on atrial-esophageal fistula following AF ablation.
abstract: BACKGROUND
  Ablation for atrial fibrillation (AF) requires energy delivery in close proximity to the esophagus (Eso) which has accounted for the LA-Eso fistula, a rare but life-threatening complication.
  
  
  OBJECTIVE
  We evaluated an Eso cooling system to protect the Eso during RF ablation.
  
  
  RESULTS
  An "in vitro" heart-Eso preparation was initially used to test a temperature-controlled fluid-circulating system (EPSac [esophageal protective system]-RossHart Technologies Inc.) and an expandable compliant Eso sac during cardiac RF delivery (4 mm tip, perpendicular to the heart, 15 g pressure) at 25, 35, and 45 W, 100 +/- 5 Omega for 30 seconds with the EPSac at 25, 15, 10, and 5 degrees C. All cardiac lesions were transmural. Eso thermal injury could only be avoided with the EPSac at 10 and 5 degrees C. The system was then tested in 6 closed chest dogs, each receiving 12 RFs (LA aiming at the Eso) for 30 seconds: without EPSac (control) at 35 W (1 dog); at 45 W with EPSac at 25 degrees C (1 dog), 10 degrees C (2 dogs), and 5 degrees C (2 dogs). The EPSac volume was intentionally increased to displace the Eso toward the LA (2 dogs 5 and 10 degrees C). Eso injured control and EPSac at 25 degrees C; Eso spared EPSac at 5 and 10 degrees C, without Eso displacement. Shallow external Eso injury noted when intentionally displacing the Eso toward the LA.
  
  
  CONCLUSIONS
  The EPSac spares the Eso from collateral thermal injury. It requires circulating fluid at 5 or 10 degrees C and a compliant sac to avoid displacement of the Eso. Its safety and efficacy remain to be demonstrated in patients undergoing AF ablation.
authors: Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA. marruda88@gmail.com
authors: Mauricio S
authors: MS
authors: Arruda
authors: Luciana
authors: L
authors: Armaganijan
authors: Luigi
authors: L
authors: Di Biase
authors: Rassoll
authors: R
authors: Rashidi
authors: Andrea
authors: A
authors: Natale
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000150:complications / Q000601:surgery*; D002058:Burns, Electric / Q000209:etiology / Q000517:prevention & control; D017115:Catheter Ablation / Q000009:adverse effects* / Q000295:instrumentation*; D004285:Dogs; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004869:Equipment Safety; D004935:Esophageal Diseases / Q000209:etiology* / Q000517:prevention & control*; D004947:Esophagus / Q000293:injuries; D005240:Feasibility Studies; D005402:Fistula / Q000209:etiology / Q000517:prevention & control*; D007036:Hypothermia, Induced / Q000295:instrumentation*; D066298:In Vitro Techniques; D012756:Sheep; D016896:Treatment Outcome