title: Percutaneous epicardial left atrial appendage closure: intermediate-term results.
abstract: Chronic Percutaneous Epicardial Appendage Closure.
  
  
  OBJECTIVE
  To assess the chronic safety and feasibility of percutaneous epicardial closure of the left atrial appendage (LAA) guided by electrical navigation.
  
  
  BACKGROUND
  Atrial fibrillation (AF) is associated with stroke, and LAA occlusion may be a useful nonpharmacologic strategy for stroke prevention in AF.
  
  
  METHODS
  Percutaneous epicardial access was obtained in 6 dogs under general anesthesia. The ligation system included a grabber that captures the LAA guided by local electrograms (EGMs) and a looped hollow suture preloaded with a central wire enabling control and visualization. After a satisfactory position is confirmed the loop is tightened remotely, and the suture cut. Transesophageal echocardiography (TEE) assessed LAA dimensions and flow. LAA EGMs were recorded pre- and postclosure, and neurohormonal markers measured. Pathologic examination was performed.
  
  
  RESULTS
  LAA ligation was successful in all dogs. LAA flow was immediately abolished in 5 of 6 dogs. Disappearance of local LAA EGMs following ligation was observed in all animals. Follow-up TEE at mean 54 days (range 23-75 days) documented residual flow in only the first 2 dogs. Prior to necropsy the LAA was examined at thoracotomy in 3 animals. Following a minor design change, complete closure and fibrosis with a remnant atretic LAA was noted in all animals. No damage to adjacent structures was noted. Neurohormonal markers were unchanged.
  
  
  CONCLUSIONS
  Percutaneous epicardial LAA ligation guided by electrical navigation is feasible with promising intermediate-term results in the canine model. The technique may be useful as an alternative to existing methods of LAA obliteration in humans.
authors.affiliation: Division of Cardiovascular Disease, Department of Internal Medicine Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Bruce
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Stanton
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Asirvatham
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Danielsen
authors.forename: Susan B
authors.initials: SB
authors.lastname: Johnson
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Packer
authors.forename: Paul A
authors.initials: PA
authors.lastname: Friedman
mesh_terms: D000818:Animals; D020517:Atrial Appendage / Q000502:physiology* / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000379:methods*; D013504:Cardiovascular Surgical Procedures / Q000295:instrumentation* / Q000379:methods*; D004285:Dogs; D006329:Heart Conduction System / Q000502:physiology* / Q000601:surgery*; D008137:Longitudinal Studies