In Vivo Evaluation of Centrifugal Blood Pump for Cardiopulmonary Bypass—Spiral Pump

Abstract

The Spiral Pump (SP), a centrifugal blood pump for cardiopulmonary bypass (CPB), has been developed at the Dante Pazzanese Institute of Cardiology/Adib Jatene Foundation laboratories, with support from Sintegra Company (Pompeia, Brazil). The SP is a disposable pump with an internal rotor-a conically shaped fuse with double entrance threads. This rotor is supported by two ball bearings, attached to a stainless steel shaft fixed to the housing base. Worm gears provide axial motion to the blood column, and the rotational motion of the conically shaped impeller generates a centrifugal pumping effect, improving pump efficiency without increasing hemolysis. In vitro tests were performed to evaluate the SP's hydrodynamic performance, and in vivo experiments were performed to evaluate hemodynamic impact during usual CPB. A commercially available centrifugal blood pump was used as reference. In vivo experiments were conducted in six male pigs weighing between 60 and 90 kg, placed on CPB for 6 h each. Blood samples were collected just before CPB (T0) and after every hour of CPB (T1-T6) for hemolysis determination and laboratory tests (hematological and biochemical). Values of blood pressure, mean flow, pump rotational speed, and corporeal temperature were recorded. Also, ergonomic conditions were recorded: presence of noise, difficulty in removing air bubbles, trouble in installing the pump in the drive module (console), and difficulties in mounting the CPB circuit. Comparing the laboratory and hemolysis results for the SP with those of the reference pump, we can conclude that there is no significant difference between the two devices. In addition, reports made by medical staff and perfusionists described a close similarity between the two devices. During in vivo experiments, the SP maintained blood flow and pressure at physiological levels, consistent with those applied in cardiac surgery with CPB, without presenting any malfunction. Also, the SP needed lower rotational speed to obtain average blood flow and pressure, compared with the reference pump.

Apical aortic blood pump preclinical assessment for long‐term use: Durability test and stator topology to reduce wear in the bearing system

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Desenvolvimento e estudo in vitro de um dispositivo de suporte circulatório temporário

“…Um problema comumente associado ao bombeamento de sangue é a ocorrência de hemólise, ou seja, ocorre a ruptura da membrana das hemácias, permitindo a liberação da hemoglobina para o plasma, constituindo a hemoglobina livre. A hemoglobinúria é o fenômeno gerado pelo aumento de hemoglobina livre no plasma (PFH), como consequência da hemólise (Silva, 2013).…”

“…A hemólise é um fator muito importante a ser estudado em um projeto de bomba de sangue, pois o índice de hemólise se dá pela intensidade do trauma causado pelo bombeamento às células vermelhas, liberando hemoglobina no plasma como subproduto da quebra das hemácias do sangue (Silva, 2013…”