Mechanical performance comparison between RotaFlow and CentriMag centrifugal blood pumps in an adult ECLS model

Introduction: Centrifugal blood pumps have been widely adopted in conventional adult cardiopulmonary bypass and circulatory assist procedures. Different brands of centrifugal blood pumps incorporate distinct designs which affect pump performance. In this adult extracorporeal life support (ECLS) model, the performances of two brands of centrifugal blood pump (RotaFlow blood pump and CentriMag blood pump) were compared. Methods: The simulated adult ECLS circuit used in this study included a centrifugal blood pump, Quadrox D membrane oxygenator and Sorin adult ECLS tubing package. A Sorin Cardiovascular (R) VVR (R) 4000i venous reservoir (Sorin S.p.A., Milan, Italy) with a Hoffman clamp served as a pseudo-patient. The circuit was primed with 900ml heparinized human packed red blood cells and 300ml lactated Ringer's solution (total volume 1200 ml, corrected hematocrit 40%). Trials were conducted at normothermia (36 degrees C). Performance, including circuit pressure and flow rate, was measured for every setting analyzed. Results: The shut-off pressure of the RotaFlow was higher than the CentriMag at all measurement points given the same rotation speed (p < 0.0001). The shut-off pressure differential between the two centrifugal blood pumps was significant and increased given higher rotation speeds (p < 0.0001). The RotaFlow blood pump has higher maximal flow rate (9.08 +/- 0.01L/min) compared with the CentriMag blood pump (8.37 +/- 0.02L/min) (p < 0.0001). The blood flow rate differential between the two pumps when measured at the same revolutions per minute (RPM) ranged from 1.64L/min to 1.73L/min. Conclusions: The results obtained in this experiment demonstrate that the RotaFlow has a higher shut-off pressure (less retrograde flow) and maximal blood flow rate than the CentriMag blood pump. Findings support the conclusion that the RotaFlow disposable pump head has a better mechanical performance than the CentriMag. In addition, the RotaFlow disposable pump is 20-30 times less expensive than the CentriMag.