title: Interim results of the 5-box thoracoscopic maze procedure.
abstract: BACKGROUND
  In accordance with the Cox-Maze paradigm, successful treatment of atrial fibrillation (AF) requires (1) complete posterior left atrial isolation, (2) elimination of corridors for perimitral reentry, (3) elimination of cardiac venous (superior vena cava and coronary sinus) arrhythmogenic foci, (4) complete autonomic denervation, and (5) occlusion or removal of the left atrial appendage. Using a totally thoracoscopic approach, isolation of all left atrial arrhythmogenic substrate is achieved through the creation of 5 discrete but contiguous compartments, thereby enabling unambiguous verification with bidirectional block. Since no previous closed-chest procedure incorporates all these end points, an update on patient outcomes is reported.
  
  
  METHODS
  One hundred seventy-nine consecutive patients with antiarrhythmic drug-resistant AF (3 paroxysmal, 5 persistent, 171 longstanding persistent cases), known preoperatively for 5.7 (range 0.5 to 25) years, underwent the 5-box thoracoscopic Maze procedure. Only 1 patient suffered a serious procedural complication (sternotomy for pulmonary artery injury). Postoperative rhythm surveillance consisted of 1 week of continuous ambulatory monitoring at 3, 6, 13, and 24 months. Failure was defined as any tachyarrhythmia exceeding 30 seconds beyond the 3-month anniversary.
  
  
  RESULTS
  Freedom from AF was observed in 137 of 142 patients at 3 months, 115 of 119 patients at 6 months, 75 of 78 patients at 13 months, and 24 of 25 patients at 24 months. Two patients remain in sinus rhythm on low-dose antiarrhythmia therapy. Warfarin is discontinued only after the first monitoring session confirms rhythm stability.
  
  
  CONCLUSIONS
  Replication of the left atrial Cox-Maze lesion set through a totally thoracoscopic approach isolates virtually all arrhythmogenic substrate. Meticulous verification of compartment integrity allows for outcomes equivalent to the Cox-Maze benchmark.
authors.affiliation: Division of Cardiac Surgery, Ohio State University, Columbus, Ohio 43210, USA. johnsirak@gmail.com
authors.forename: John H
authors.initials: JH
authors.lastname: Sirak
authors.forename: David
authors.initials: D
authors.lastname: Schwartzman
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000601:surgery*; D001281:Atrial Fibrillation / Q000601:surgery*; D006348:Cardiac Surgical Procedures / Q000379:methods; D017115:Catheter Ablation / Q000379:methods*; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D020708:Thoracoscopes; D013906:Thoracoscopy / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome