Evaluation of Hemolysis in the VentrAssist Implantable Rotary Blood Pump

Abstract

The VentrAssist implantable rotary blood pump (IRBP) is an implantable centrifugal blood pump with a hydrodynamically suspended impeller; optimal efficiency requires small running clearances (70-300 microm). The effect of running clearance and polish on hemolysis was evaluated in vitro. Three different human blood suspensions were compared: phosphate buffered saline (PBS), plasma volume expander (Hemaccel), and whole blood. The test conditions were: blood hematocrit 30%, flow rate 5 L/min, pressure across pump 100 mm Hg, 6 h flow period, and 37 degrees C. Normalized Index of Hemolysis (NIH) for the Biomedicus BP-80, used as a control, was: 0.0040 +/- 0.0023 (n = 9; x +/- SD) and 0.00014 +/- 0.00009 (n = 5) for pooled blood suspensions in PBS and Hemaccel respectively, and 0.00053 +/- 0.0002 (n = 3) in whole blood. Hemolysis was reduced by improved surface finish and unaffected by running clearance. NIH for the VentrAssist IRBP with 0.2 microm Ra surface finish was 0.000167 +/- 0.00007 (n = 4) g/100 L in whole human blood, demonstrating minimal hemolysis.

Haemolysis in patients with ventricular assist devices: major differences between systems☆

“…However, our results are consistent with previous studies, which indicate low haemolysis in the axial HeartMate II system in patients [21] and negligible haemolysis by the centrifugal VentrAssist device in experimental studies [22,23]. These observations Fig.…”

Axial and centrifugal continuous-flow rotary pumps: A translation from pump mechanics to clinical practice

“…31 The reported incidence of hemolysis for the HeartMate II axial rotary pump is 0.06, 0.02, and 0.13 events per patient-year in its BTT U.S., destination therapy U.S., and European multicenter clinical trials, respectively. 33 In a study comparing hemolysis indices in CF LVAD patients 34 supported by the axial CF rotary pump (HeartMate II) and the (VentrAssist) [35][36] centrifugal CF rotary pump, patients with the centrifugal LVAD displayed normal haptoglobin levels, low plasma free hemoglobin, and moderately increased LDH. In comparison, the HeartMate II patients showed lower haptoglobin and higher free hemoglobin and LDH values.…”

Computational Fluid Dynamics Analysis of the Pediatric Tiny Centrifugal Blood Pump (TinyPump)

“…This condition was near the condition on which the CFD analysis was performed. Details concerning the experimental conditions can be found elsewhere (18,19). The citrate phosphate dextran (CPD) anticoagulated fresh porcine blood was used as a working fluid at 24 ° C. The normalized index of hemolysis (NIH) was calculated using the following the equation (Eq.…”