title: Is Continuous Flow Superior to Pulsatile Flow in Single Ventricle Mechanical Support? Results from a Large Animal Pilot Study.
abstract: Durable mechanical support in situations of physiologic single ventricle has been met with little success so far, particularly in small children. We created an animal model to investigate whether pulsatile or continuous flow would be superior. Three 1 month old sheep (10-16 kg) were instrumented. Via sternotomy and with cardiopulmonary bypass, a large ventricular septal defect and atrial septal defect were created. The left ventricle was cannulated using a Berlin Heart inflow cannula. This was connected sequentially to a continuous flow device (Thoratec HeartMate X, Pleasanton, CA) and to a pulsatile device (Berlin Heart Excor, The Woodlands, TX). Outflow was via a Y-graft to both aorta and pulmonary artery, striving for equal flow to both. Atrial filling pressures were controlled with volume infusions over a wide range. Under comparable loading conditions, significantly higher maximum flow was obtained by HeartMate X than by Excor (4.95 ± 1.27 L/min [range, 3.84-6.34 L/min] for HeartMate X vs. 1.80 ± 0.85 L/min [range, 1.01-2.7 L/min] for Excor; p < 0.05). Judging from this limited animal study, in single ventricle scenarios, continuous flow devices may achieve higher pump flows than pulsatile devices when provided with similar filling pressures. Their clinical use should be investigated. More extensive experimental studies are needed.
authors: From the *Department of Cardiothoracic Surgery, Stanford University, Stanford, California; †Department of Medicine and Epidemiology, University of California, Davis, School of Veterinary Medicine, Davis, California; ‡Thoratec Corp., Pleasanton, California; §Lucile Packard Children's Hospital, Palo Alto, California; and ¶Cardiothoracic Surgery, Children's Hospital and Research Center Oakland, Oakland, California.
authors: Yasuhiro
authors: Y
authors: Fujii
authors: Giuseppe
authors: G
authors: Ferro
authors: Hiroshi
authors: H
authors: Kagawa
authors: Luca
authors: L
authors: Centola
authors: Liqun
authors: L
authors: Zhu
authors: William T
authors: WT
authors: Ferrier
authors: Linda
authors: L
authors: Talken
authors: R Kirk
authors: RK
authors: Riemer
authors: Katsuhide
authors: K
authors: Maeda
authors: Teimour
authors: T
authors: Nasirov
authors: Bill
authors: B
authors: Hodges
authors: Saleh
authors: S
authors: Amirriazi
authors: Eric
authors: E
authors: Lee
authors: Donald
authors: D
authors: Sheff
authors: Judith
authors: J
authors: May
authors: Robert
authors: R
authors: May
authors: Olaf
authors: O
authors: Reinhartz
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D006330:Heart Defects, Congenital / Q000150:complications*; D006333:Heart Failure / Q000150:complications* / Q000601:surgery*; D006353:Heart-Assist Devices; D010865:Pilot Projects; D011673:Pulsatile Flow / Q000502:physiology*; D034561:Sheep, Domestic