title: Bi-ventricular axial micropump: impact on blood cell integrity.
abstract: OBJECTIVE
  Off-pump coronary artery bypass grafting has stimulated the development of micro-pumps designed to prevent the hemodynamic instability induced by heart luxation for the exposure of target vessels of the posterior wall. Impella (Aachen, Germany) developed micro-pumps with a miniaturized propeller system for both sides of the heart. The aim of this study was to analyze the impact of both pumps working together on blood cell integrity.
  
  
  METHODS
  Both right and left-sided micro-pumps were implanted in 5 calves (body weight, 72_4 Kg) during 3 h. Blood samples for hematology and hemolysis parameters were drawn hourly.
  
  
  RESULTS
  Both pumps performed well with a flow of 3.6 L +/- 0.3 L during the 3 h of the experiment with stable hemodynamic conditions. Mixed venous oxygen saturation was 63.4 +/- 15.2% at baseline and 63.8 +/- 16.3% at the end of the experiment (P = ns). Red cell count, LDH and free plasma hemoglobin were 6.7 +/- 2.1 x 10(12)/L, 1807 +/- 437 IU/L, and 32 +/- 9 mg/L at baseline vs. 6.1 +/- 2.1 x 10(12)/L, 1871 +/- 410 IU/L, and 52 +/- 9 mg/L at the end of the experiment (P = ns for all comparisons). Platelet count exhibited a non-significant drop (872 +/- 126 vs. 715 +/- 22 x 10(9)/L).
  
  
  CONCLUSIONS
  This double pump system based on the Archimed screw principle is hematologically well tolerated under conditions of prolonged cardiac assist.
authors.affiliation: Department of Cardio-Vascular Surgery, CHUV (Centre Hospitalier Universitaire Vaudois), Lausanne. Xavier.Mueller@chuv.hospvd.ch
authors.forename: X M
authors.initials: XM
authors.lastname: Mueller
authors.forename: Y
authors.initials: Y
authors.lastname: Boone
authors.forename: M
authors.initials: M
authors.lastname: Augstburger
authors.forename: J
authors.initials: J
authors.lastname: Horisberger
authors.forename: L K
authors.initials: LK
authors.lastname: von Segesser
mesh_terms: D000818:Animals; D002417:Cattle; D001026:Coronary Artery Bypass / Q000295:instrumentation*; D004867:Equipment Design; D004906:Erythrocyte Count; D006353:Heart-Assist Devices; D006400:Hematocrit; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D010976:Platelet Count