title: Pilot study of transesophageal endoscopic epicardial coagulation by submucosal endoscopy with the mucosal flap safety valve technique (with videos).
abstract: BACKGROUND
  We previously demonstrated that the thoracic cavity could be safely accessed by submucosal endoscopy with the mucosal flap safety valve (SEMF) technique.
  
  
  OBJECTIVE
  To evaluate the technical feasibility of transesophageal access to the heart and epicardial ablation.
  
  
  METHODS
  One-week survival study with 5 porcine models.
  
  
  METHODS
  Animal laboratory with general anesthesia.
  
  
  METHODS
  High-pressure carbon dioxide injection and balloon dissection created a large submucosal working space for insertion of a cap-fitted endoscope. A myotomy was performed inside the submucosal space. The thoracic cavity was endoscopically accessed through the myotomy site. A pericardial window was created with a needle-knife. A spot coagulation of the epicardium was performed with a heat probe and a hook-knife. The myotomy site was sealed with the overlying mucosal flap, and the mucosal entry site was closed with clips.
  
  
  METHODS
  An endoscopy and a necropsy were performed to study the esophagus, mediastinum, pericardial space, and cautery locations on the epicardium one week after the procedure.
  
  
  RESULTS
  Epicardial coagulation was successfully performed within 30 minutes in 4 of the 5 pigs. Follow-up endoscopy demonstrated completely sealed myotomy sites by the overlying mucosal flap. There was no gross contamination or signs of contamination in the thoracic cavity. The pericardial space was normal in appearance. The epicardial coagulation sites were healing, without exudative ulceration.
  
  
  CONCLUSIONS
  The SEMF technique allowed endoscopic access to the upper mediastinum, the pericardium, and the epicardium via the esophagus, along with a minimal intervention on the epicardium.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sumiyama
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gostout
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Rajan
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Bakken
authors.forename: Mary A
authors.initials: MA
authors.lastname: Knipschield
authors.forename: Sydney
authors.initials: S
authors.lastname: Chung
authors.forename: Peter B
authors.initials: PB
authors.lastname: Cotton
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hawes
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Kalloo
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Kantsevoy
authors.forename: Pankaj J
authors.initials: PJ
authors.lastname: Pasricha
mesh_terms: D000818:Animals; D004564:Electrocoagulation / Q000379:methods*; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D004947:Esophagus; D005240:Feasibility Studies; D010496:Pericardium / Q000601:surgery*; D010865:Pilot Projects; D035422:Pleural Cavity; D013552:Swine; D013997:Time Factors