title: Direct percutaneous left ventricular access and port closure: pre-clinical feasibility.
abstract: OBJECTIVE
  This study sought to evaluate feasibility of nonsurgical transthoracic catheter-based left ventricular (LV) access and closure.
  
  
  BACKGROUND
  Implanting large devices, such as mitral or aortic valve prostheses, into the heart requires surgical exposure and repair. Reliable percutaneous direct transthoracic LV access and closure would allow new nonsurgical therapeutic procedures.
  
  
  METHODS
  Percutaneous direct LV access was performed in 19 swine using real-time magnetic resonance imaging (MRI) and an "active" MRI needle antenna to deliver an 18-F introducer sheath. The LV access ports were closed percutaneously using a commercial ventricular septal defect occluder and an "active" MRI delivery cable for enhanced visibility. We used "permissive pericardial tamponade" (temporary fluid instillation to separate the 2 pericardial layers) to avoid pericardial entrapment by the epicardial disk. Techniques were developed in 8 animals, and 11 more were followed up to 3 months by MRI and histopathology.
  
  
  RESULTS
  Imaging guidance allowed 18-F sheath access and closure with appropriate positioning of the occluder inside the transmyocardial tunnel. Of the survival cohort, immediate hemostasis was achieved in 8 of 11 patients. Failure modes included pericardial entrapment by the epicardial occluder disk (n = 2) and a true-apex entry site that prevented hemostatic apposition of the endocardial disk (n = 1). Reactive pericardial effusion (192 ± 118 ml) accumulated 5 ± 1 days after the procedure, requiring 1-time drainage. At 3 months, LV function was preserved, and the device was endothelialized.
  
  
  CONCLUSIONS
  Direct percutaneous LV access and closure is feasible using real-time MRI. A commercial occluder achieved hemostasis without evident deleterious effects on the LV. Having established the concept, further clinical development of this approach appears realistic.
authors.affiliation: Cardiovascular and Pulmonary Branch, Division of Intramural Research, the National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Israel M
authors.initials: IM
authors.lastname: Barbash
authors.forename: Christina E
authors.initials: CE
authors.lastname: Saikus
authors.forename: Anthony Z
authors.initials: AZ
authors.lastname: Faranesh
authors.forename: Kanishka
authors.initials: K
authors.lastname: Ratnayaka
authors.forename: Ozgur
authors.initials: O
authors.lastname: Kocaturk
authors.forename: Marcus Y
authors.initials: MY
authors.lastname: Chen
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Bell
authors.forename: Renu
authors.initials: R
authors.lastname: Virmani
authors.forename: William H
authors.initials: WH
authors.lastname: Schenke
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 / Q000379:methods*; D002305:Cardiac Tamponade / Q000209:etiology; D057785:Catheters; D017023:Coronary Angiography / Q000379:methods; D004867:Equipment Design; D005240:Feasibility Studies; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology; D006439:Hemodynamics; D053783:Magnetic Resonance Imaging, Interventional; D023421:Models, Animal; D010490:Pericardial Effusion / Q000209:etiology; D011474:Prosthesis Design; D055989:Septal Occluder Device; D013318:Stroke Volume; D013552:Swine; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016277:Ventricular Function, Left