Objective: The aim was to evaluate the performance of a newly developed magnetically suspended centrifugal pump head intended for use as a ventricular assistance device with a newly developed extracorporeal membrane oxygenator setup. Methods: In an experimental setup, an extracorporeal membrane oxygenator circuit was established in three calves with a mean weight of 68.2 ± 2.0 kg. A magnetically levitated centrifugal pump was tested, along with a newly designed extracorporeal membrane oxygenator console, at three different flow ranges: (a) 0.0 to 5.2 L/min, (b) 0.0 to 7.1 L/min, and (c) 0.0 to 6.0 L/min. For each setup, the animals were supported by a circuit for 6 h. Blood samples were collected just before caridiopulmonary bypass (CPB) after 10 min on bypass and after 1, 2, 5, and 6 h of perfusion for hemolysis determination and biochemical tests. Values were recorded for blood pressure, mean flow, and pump rotational speed. Analysis of variance was used for repeated measurements. Results: Mean pump flows achieved during the three 6 h pump runs for the three pump heads studied were as follows: (a) flow range 0.0 to 5.2 L/min, 3.6 ± 1.5 L/min, (b) flow range 0.0 to 7.1 L/min, 4.9 ± 1.3 L/min, and (c) flow range 0.0 to 6.0 L/min, 3.8 ± 1.5 L/min. Blood trauma, evaluated by plasma hemoglobin and lactate dehydrogenase levels, did not help in detecting any significant hemolysis. Thrombocytes and white blood cell count profiles showed no significant differences between the groups at the end of the 6 h perfusion. At the end of testing, no clot deposition was found in the oxygenator, and there was no evidence of peripheral emboli. Conclusion: The results suggest that the newly developed magnetically suspended centrifugal pump head provides satisfactory hydrodynamic performance in an acute perfusion scenario without increasing hemolysis.
Backflow effects on mass flow gain factor in a centrifugal pump