Affiliation:
1. Artificial Organ Lab, Department of Surgery University of Maryland School of Medicine Baltimore Maryland USA
2. Fischell Department of Bioengineering, A. James Clark School of Engineering University of Maryland College Park Maryland USA
Abstract
AbstractBackgroundHigh mechanical shear stress (HMSS) generated by blood pumps during mechanical circulatory support induces blood damage (or function alteration) not only of blood cell components but also of plasma proteins.MethodsIn the present study, fresh, healthy human blood was used to prime a blood circuit assisted by a CentriMag centrifugal pump at a flow rate of 4.5 L/min under three pump pressure heads (75, 150, and 350 mm Hg) for 4 h. Blood samples were collected for analyses of plasma‐free hemoglobin (PFH), von Willebrand factor (VWF) degradation and platelet glycoprotein (GP) IIb/IIIa receptor shedding.ResultsThe extent of all investigated aspects of blood damage increased with increasing cross‐pump pressure and duration. Loss of high‐molecular‐weight multimers (HMWM)‐VWF in Loop 2 and Loop 3 significantly increased after 2 h. PFH, loss of HMWM‐VWF, and platelet GPIIb/IIIa receptor shedding showed a good linear correlation with mean shear stress corresponding to the three pump pressure heads.ConclusionsHMSS could damage red blood cells, cause pathological VWF degradation, and induce platelet activation and platelet receptor shedding. Different blood components can be damaged to different degrees by HMSS; VWF and VWF‐enhanced platelet activation may be more susceptible to HMSS.
Funder
National Heart, Lung, and Blood Institute