Development of an in-vitro model for extracorporeal blood pumps to study the effects of artificial pulsatility on human blood

Barbara Zieger; Denise Schneider; Sam Joé Brixius; Christian Scherer; Armin Buchwald; Georg Trummer; Martin Czerny; Friedhelm Beyersdorf; Hans-Jörg Busch; Christoph Benk; Jan-Steffen Pooth

doi:10.3389/fmed.2023.1237002

Development of an in-vitro model for extracorporeal blood pumps to study the effects of artificial pulsatility on human blood

Front Med (Lausanne). 2023 Aug 28:10:1237002. doi: 10.3389/fmed.2023.1237002. eCollection 2023.

Affiliations

¹ Department of Pediatrics and Adolescent Medicine, University Medical Centre Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
² Department of Cardiovascular Surgery, University Medical Centre Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
³ Institute for Clinical Chemistry and Laboratory Medicine, University Medical Centre Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
⁴ Department of Emergency Medicine, University Medical Centre Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.

Abstract

Introduction: The application of extracorporeal circulation (ECC) systems is known to be associated with several implications regarding hemolysis, inflammation, and coagulation. In the last years, systems with pulsatile blood flow are increasingly used with the intention to improve hemodynamics in reperfusion. However, their implications on the aforementioned aspects remain largely unknown. To investigate the effects of pulsatility, this ex-vivo study was initiated.

Methods: Test circuits (primed with human whole blood) were set up in accordance with the recommendations of international standards for in-vitro evaluation of new components and systems of ECC. Diagonal pumps were either set up with non-pulsatile (n = 5, NPG) or pulsatile (n = 5, PG) pump settings and evaluated for 6 h. All analyses were conducted with human whole blood. Blood samples were repeatedly drawn from the test circuits and analyzed regarding free hemoglobin, interleukin 8 (IL-8), platelet aggregation and acquired von Willebrand syndrome (AVWS).

Results: After 1 h of circulation, a significant coagulation impairment (impaired platelet function and AVWS) was observed in both groups. After 6 h of circulation, increased IL-8 concentrations were measured in both groups (NPG: 0.05 ± 0.03 pg./mL, PG: 0.03 ± 0.01 pg./mL, p = 0.48). Pulsatile pump flow resulted in significantly increased hemolysis after 6 h of circulation (NPG: 37.3 ± 12.4 mg/100 L; PG: 59.6 ± 14.5 mg/100 L; p < 0.05).

Conclusion: Our results indicate that the coagulative impairment takes place in the early phase of ECC. Pulsatility did not affect the occurrence of AVWS ex-vivo. Prolonged durations of pulsatile pump flow led to increased hemolysis and therefore, its prolonged use should be employed cautiously in clinical practice with appropriate monitoring.

Keywords: acquired von Willebrand syndrome; diagonal pumps; ex-vivo; extracorporeal circulation; hemolysis; in-vitro; platelet activation; pulsatility.