title: Fully percutaneous transthoracic left atrial entry and closure as a potential access route for transcatheter mitral valve interventions.
abstract: BACKGROUND
  Percutaneous access for mitral interventions is currently limited to transapical and transseptal routes, both of which have shortcomings. We hypothesized that the left atrium could be accessed directly through the posterior chest wall under imaging guidance.
  
  
  RESULTS
  We tested percutaneous transthoracic left atrial access in 12 animals (10 pigs and 2 sheep) under real-time magnetic resonance imaging or x-ray fluoroscopy plus C-arm computed tomographic guidance. The pleural space was insufflated with CO2 to displace the lung, an 18F sheath was delivered to the left atrium, and the left atrial port was closed using an off-the-shelf nitinol cardiac occluder. Animals were survived for a minimum of 7 days. The left atrial was accessed, and the port was closed successfully in 12/12 animals. There was no procedural mortality and only 1 hemodynamically insignificant pericardial effusion was observed at follow-up. We also successfully performed the procedure on 3 human cadavers. A simulated trajectory to the left atrium was present in all of 10 human cardiac computed tomographic angiograms analyzed.
  
  
  CONCLUSIONS
  Percutaneous transthoracic left atrial access is feasible without instrumenting the left ventricular myocardium. In our experience, magnetic resonance imaging offers superb visualization of anatomic structures with the ability to monitor and address complications in real-time, although x-ray guidance seems feasible. Clinical translation seems realistic based on human cardiac computed tomographic analysis and cadaver testing. This technique could provide a direct nonsurgical access route for future transcatheter mitral implantation.
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: Toby
authors.initials: T
authors.lastname: Rogers
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: Kanishka
authors.initials: K
authors.lastname: Ratnayaka
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: William H
authors.initials: WH
authors.lastname: Schenke
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: Merdim
authors.initials: M
authors.lastname: Sonmez
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: Ozgur
authors.initials: O
authors.lastname: Kocaturk
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Mazal
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: Marcus Y
authors.initials: MY
authors.lastname: Chen
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: Moshe Y
authors.initials: MY
authors.lastname: Flugelman
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: James F
authors.initials: JF
authors.lastname: Troendle
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.).
authors.forename: Anthony Z
authors.initials: AZ
authors.lastname: Faranesh
authors.affiliation: From the Cardiovascular and Pulmonary Branch, Division of Intramural Research (T.R., K.R., W.H.S., M.S., O.K., J.R.M., M.Y.C., A.Z.F., R.J.L.) and Office of Biostatistics Research, Division of Cardiovascular Sciences (J.F.T.), National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD; Department of Cardiology, Children's National Medical Center, Washington DC (K.R.); Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey (O.K.); and Department of Cardiology, Carmel Medical Center, Haifa, Israel (M.Y.F.). lederman@nih.gov.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lederman
mesh_terms: D000368:Aged; D000818:Animals; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D012756:Sheep; D013552:Swine; D014057:Tomography, X-Ray Computed
keywords: catheterization; endovascular procedures; heart valve prosthesis implantation; magnetic resonance imaging, interventional; mitral valve