Evaluation of hemolysis in the VentrAssist implantable rotary blood pump.
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.
James
Natalie L
NL
VentrAssist Division, Ventracor Ltd., Chatswood, Sydney, New South Wales, Australia. natalie.james@ventracor.com
Wilkinson
Carmel M
CM
Lingard
Nicole L
NL
van der Meer
Anita L
AL
Woodard
John C
JC
D002498:Centrifugation; D003470:Culture Media / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology*; D005780:Gelatin / Q000494:pharmacology; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006461:Hemolysis / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D011108:Polymers / Q000494:pharmacology; D011474:Prosthesis Design; D013535:Suspensions / Q000494:pharmacology
D003470:Culture Media; C115675:Hemaccel; D011108:Polymers; D013535:Suspensions; D005780:Gelatin