In Vitro Comparison of the Blood Handling by the Constrained Vortex and Twin Roller Blood Pumps

(J. Extra-Corpor. Technol. 19[3] p. 316-321 Fall 1987, 30 ref.) Several authors and manufacturers refer to the superior blood handling capability of the constrained vortex blood pump (CVP) design compared to the roller pump (RP). Little, if any, scientific evidence has been presented to support this thinking. The hypothesis that the RP and the CVP are equivalent in regard to trauma to blood cellular elements and proteins was tested. The RP, a Cobe Roller Pump (CRP), was tested utilizing a new longterm formulation of PVC tubing. Two models of the CVP were tested, the Bio-Medicus Centrifugal Pump (BCP) and the Sarns Centrifugal Pump (SCP). Similar circuits were constructed for the three pumps and fresh human blood was recirculated at 35°C for 48 hours. The circuits allowed control of pH, pCO2, pO2 and after load. An aliquot of test blood was maintained at 35°C for a control. The results from three separate trials were computed. The BCP test blood exhibited less hemolysis (p.05) in the titer of clottable fibrinogen between the other groups. The SCP and the CRP were equivalent with regard to blood handling for up to 32 hours of in vitro recirculation. The BCP caused less alteration of red blood cells and fibrinogen than the SCP and CRP