title: Intentional Right Atrial Exit and Carbon Dioxide Insufflation to Facilitate Subxiphoid Needle Entry Into the Empty Pericardial Space: First Human Experience.
abstract: OBJECTIVE
  The purpose of this study was to test whether a microcatheter can safely be advanced across the right atrial appendage to access the pericardium and then withdrawn despite subsequent high-intensity anticoagulation. We also tested whether transatrial pericardial insufflation of carbon dioxide (CO2) would enhance the safety of subxiphoid needle access to the empty pericardium by separating the heart from the anterior pericardium.
  
  
  BACKGROUND
  Subxiphoid needle access to the empty pericardium, required for left atrial suture ligation and epicardial ablation for rhythm disorders, risks myocardial or coronary laceration.
  
  
  METHODS
  A catheter from the femoral vein engaged the right atrial appendage for angiographic confirmation of position. Through that catheter, the back end of a 0.014- or 0.018-inch guidewire crossed the right atrial wall to enter the pericardium and delivered a 2.4-F microcatheter. CO21 to 2 ml/kg was insufflated into the pericardium immediately before subxiphoid needle access under lateral projection fluoroscopy. Thirteen patients undergoing subxiphoid suture ligation of the left atrial appendage consented to participate in this research protocol.
  
  
  RESULTS
  Right atrial exit succeeded in 11 subjects (85%) and failed uneventfully in 2 subjects. CO2insufflation of 96 ± 22 ml achieved 12 ± 4 mm separation of the anterior pericardium from the myocardial wall, allowed rapid and successful subxiphoid anterior needle and guidewire entry in all 11 subjects, and did not have any evident hemodynamic effects. The immediate pericardial aspirate was serous in all but 1 subject.
  
  
  CONCLUSIONS
  We report the first human intentional transatrial exit procedure. Transatrial microcatheter access to the pericardium can be achieved safely. Pericardial insufflation with CO2makes subxiphoid access to the empty pericardium rapid and safe. Although our clinical experience to date remains small, with further experience, this approach may prevent the life-threatening complications of "dry" subxiphoid pericardial access.
authors.affiliation: Institute for Structural Heart Disease, Division of Cardiology, Henry Ford Health System, Detroit, Michigan.
authors.forename: Adam B
authors.initials: AB
authors.lastname: Greenbaum
authors.affiliation: Cardiovascular and Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, Bethesda, Maryland.
authors.forename: Toby
authors.initials: T
authors.lastname: Rogers
authors.affiliation: Division of Cardiac Surgery, Henry Ford Health System, Detroit, Michigan.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Paone
authors.affiliation: Institute for Structural Heart Disease, Division of Cardiology, Henry Ford Health System, Detroit, Michigan.
authors.forename: Shawn E
authors.initials: SE
authors.lastname: Flynn
authors.affiliation: Institute for Structural Heart Disease, Division of Cardiology, Henry Ford Health System, Detroit, Michigan.
authors.forename: Mayra E
authors.initials: ME
authors.lastname: Guerrero
authors.affiliation: Institute for Structural Heart Disease, Division of Cardiology, Henry Ford Health System, Detroit, Michigan.
authors.forename: William W
authors.initials: WW
authors.lastname: O'Neill
authors.affiliation: Cardiovascular and Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, Bethesda, Maryland.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lederman
keywords: epicardial ablation; left atrial appendage ligation; pericardial access; structural heart disease; transatrial exit