Mitigation effect of cell exclusion on blood damage in spiral groove bearings

Chris Hoi Houng Chan, Tomotaka Murashige, Shelby A. Bieritz, Clayton Semenzin, Amanda Smith, Laura Leslie, Michael J. Simmonds and Geoff D. Tansley J Biomech DOI 10.1016/j.jbiomech.2022.111394

Abstract: Cell exclusion in spiral groove bearing (SGB) excludes red blood cells from high shear regions in the bearing gaps and potentially reduce haemolysis in rotary blood pumps. However, this mechanobiological phenomenon has been observed in ultra-low blood haematocrit only, whether it can mitigate blood damage in a clinically-relevant blood haematocrit remains unknown. This study examined whether cell exclusion in a SGB alters haemolysis and/or high-molecular-weight von Willebrand factor (HMW vWF) multimer degradation. Citrated human blood was adjusted to 35 % haematocrit and exposed to a SGB (n = 6) and grooveless disc (n = 3, as a non-cell exclusion control) incorporated into a custom-built Couette test rig operating at 2000RPM for an hour; shearing gaps were 20, 30, and 40 μm.