title: A modified LVAD technique to augment caval and pulmonary arterial blood flow in the "failing Fontan" circulation.
abstract: BACKGROUND
  There are minimal circulatory support options for patients with a failing Fontan. The Heartmate II (HMII) left ventricular assist device (Thoratec, Bedford, MA) in its packaged state cannot augment caval/pulmonary arterial blood flow.
  
  
  OBJECTIVE
  We hypothesized that a modified HMII pump could augment caval and pulmonary arterial blood flow.
  
  
  METHODS
  A bifurcated ringed Gore-Tex graft (W. L. Gore & Associates, Flagstaff, AZ) was sewn to the HMII inflow, and the outflow graft transected and tapered from 16 mm to 8 mm in diameter. In three sheep, the inflow and outflow grafts were anastomosed end-to-side to both cava and the pulmonary artery.
  
  
  RESULTS
  Following baseline measurements, the pump speed was increased to 8000 revolutions per minute (RPMs). Compared to baseline, at 8000 RPMs, there were no significant differences in mean arterial, central venous, or pulmonary arterial pressure. However, there was a significant decrease in right ventricular diastolic diameter (3.1 ± 0.1 vs. 1.8 ± 0.2 cm, R = 0.6, p = 0.02) and similarly a decrease in pulmonary arterial pulse pressure (8.5 ± 2.1 vs. 2.1 ± 2.9 mmHg, p = 0.01). As pump speed increased, there was a corresponding increase in pump flow and power, with a decrease in pulsatility index.
  
  
  CONCLUSIONS
  These findings suggest that the HMII may be modified to provide caval/pulmonary circulatory support for the failing Fontan circulation.
authors.affiliation: Department of Surgery, University of Rochester Medical Center, Rochester, New York.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Swartz
authors.affiliation: Department of Veterinary Medicine, University of Rochester Medical Center, Rochester, New York.
authors.forename: Louis
authors.initials: L
authors.lastname: DiVincenti
authors.affiliation: Department of Surgery, University of Rochester Medical Center, Rochester, New York.
authors.forename: Karen
authors.initials: K
authors.lastname: Smith
authors.affiliation: Department of Veterinary Medicine, University of Rochester Medical Center, Rochester, New York.
authors.forename: Robin
authors.initials: R
authors.lastname: Westcott
authors.affiliation: Department of Surgery, University of Rochester Medical Center, Rochester, New York.
authors.forename: Kevin
authors.initials: K
authors.lastname: Belmont
authors.affiliation: Department of Surgery, University of Rochester Medical Center, Rochester, New York.
authors.forename: William
authors.initials: W
authors.lastname: Harris
authors.affiliation: Department of Surgery, University of Rochester Medical Center, Rochester, New York.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gensini
authors.affiliation: Department of Surgery, University of Rochester Medical Center, Rochester, New York.
authors.forename: George M
authors.initials: GM
authors.lastname: Alfieris
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D003198:Computer Simulation; D004195:Disease Models, Animal; D005240:Feasibility Studies; D018729:Fontan Procedure / Q000009:adverse effects*; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery; D006353:Heart-Assist Devices; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D011651:Pulmonary Artery / Q000503:physiopathology*; D011652:Pulmonary Circulation / Q000502:physiology*; D012756:Sheep; D014683:Vena Cava, Superior / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology