title: Minimally invasive delivery of a novel direct epicardial assist device in a porcine heart failure model.
abstract: OBJECTIVE
  Despite advances in design, modern ventricular assist device placement involves median sternotomy and cardiopulmonary bypass and is associated with infectious/embolic complications. In this study, we examine the feasibility and function of a novel minimally invasive, non-blood-contacting epicardial assist device in a porcine ischemic cardiomyopathy model.
  
  
  METHODS
  Feasibility was first tested in an ex vivo thoracoscopic trainer box with slaughterhouse hearts. Five male Yorkshire swine underwent selective ligation of the circumflex artery to create a posterolateral infarct Twelve weeks after infarct, all animals underwent left minithoracotomy. A custom inflatable bladder was positioned over the epicardial surface of the infarct and firmly secured to the surrounding border zone myocardium with polypropylene mesh and minimally invasive mesh tacks. An external gas pulsation system actively inflated and deflated the bladder in synchrony with the cardiac cycle. All animals then underwent cardiac magnetic resonance imaging to assess ventricular function.
  
  
  RESULTS
  All subjects successfully underwent off-pump placement of the epicardial assist device via minithoracotomy. Ejection fraction significantly improved from 29.1% ± 4.8% to 39.6% ± 4.23% (P < 0.001) when compared with pretreatment. End-systolic volume decreased (76.6 ± 13.3 mL vs 62.4 ± 12.0 mL, P < 0.001) and stroke volume increased (28.6 ± 3.4 mL vs 37.9 ± 3.1 mL, P < 0.05) when assisted. No change was noted in end-diastolic volume (105.1 ± 11.4 vs 100.3 ± 12.7). On postmortem examination, mesh fixation and device position were excellent in all cases. No adverse events were encountered.
  
  
  CONCLUSIONS
  Directed epicardial assistance improves ventricular function in a porcine ischemic cardiomyopathy model and may provide a safe alternative to currently available ventricular assist device therapies. Further, the technique used for device positioning and fixation suggests that an entirely thoracoscopic approach is possible.
authors.affiliation: From the Gorman Cardiovascular Research Group, Division of Cardiac Surgery, University of Pennsylvania Health System, Philadelphia, PA USA.
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: McGarvey
authors.forename: Toru
authors.initials: T
authors.lastname: Shimaoka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takebayashi
authors.forename: Chikashi
authors.initials: C
authors.lastname: Aoki
authors.forename: Norihiro
authors.initials: N
authors.lastname: Kondo
authors.forename: Manabu
authors.initials: M
authors.lastname: Takebe
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Zsido
authors.forename: Arminder
authors.initials: A
authors.lastname: Jassar
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Gorman
authors.forename: James J
authors.initials: JJ
authors.lastname: Pilla
authors.forename: Robert C
authors.initials: RC
authors.lastname: Gorman
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005240:Feasibility Studies; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006353:Heart-Assist Devices; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D010496:Pericardium; D011474:Prosthesis Design; D013318:Stroke Volume; D013552:Swine; D013906:Thoracoscopy / Q000379:methods*; D016277:Ventricular Function, Left