title: Closed-chest transthoracic magnetic resonance imaging-guided ventricular septal defect closure in swine.
abstract: OBJECTIVE
  The aim of this study was to close ventricular septal defects (VSDs) directly through the chest wall using magnetic resonance imaging (MRI) guidance, without cardiopulmonary bypass, sternotomy, or radiation exposure.
  
  
  BACKGROUND
  Surgical, percutaneous, and hybrid management of VSD each have limitations and known morbidity.
  
  
  METHODS
  Percutaneous muscular VSDs were created in 10 naive Yorkshire swine using a transjugular laser catheter. Under real-time MRI guidance, a direct transthoracic vascular access sheath was introduced through the chest into the heart along a trajectory suitable for VSD access and closure. Through this transthoracic sheath, muscular VSDs were occluded using a commercial nitinol device. Finally, the right ventricular free wall was closed using a commercial collagen plug intended for arterial closure.
  
  
  RESULTS
  Anterior, posterior, and mid-muscular VSDs (6.8 ± 1.8 mm) were created. VSDs were closed successfully in all animals. The transthoracic access sheath was displaced in 2, both fatal. Thereafter, we tested an intracameral retention sheath to prevent this complication. Right ventricular access ports were closed successfully in all, and after as many as 30 days, healed successfully.
  
  
  CONCLUSIONS
  Real-time MRI guidance allowed closed-chest transthoracic perventricular muscular VSD closure in a clinically meaningful animal model. Once applied to patients, this approach may avoid traditional surgical, percutaneous, or open-chest transcatheter ("hybrid") risks.
authors.affiliation: Cardiovascular and Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Kanishka
authors.initials: K
authors.lastname: Ratnayaka
authors.forename: Christina E
authors.initials: CE
authors.lastname: Saikus
authors.forename: Anthony Z
authors.initials: AZ
authors.lastname: Faranesh
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Bell
authors.forename: Israel M
authors.initials: IM
authors.lastname: Barbash
authors.forename: Ozgur
authors.initials: O
authors.lastname: Kocaturk
authors.forename: Christine A
authors.initials: CA
authors.lastname: Reyes
authors.forename: Merdim
authors.initials: M
authors.lastname: Sonmez
authors.forename: William H
authors.initials: WH
authors.lastname: Schenke
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Wright
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hansen
authors.forename: Michael C
authors.initials: MC
authors.lastname: Slack
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lederman
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization / Q000009:adverse effects / Q000295:instrumentation; D004195:Disease Models, Animal; D006345:Heart Septal Defects, Ventricular / Q000473:pathology / Q000628:therapy*; D053783:Magnetic Resonance Imaging, Interventional; D011474:Prosthesis Design; D055989:Septal Occluder Device; D013552:Swine; D013997:Time Factors