Linking Computational Fluid Dynamics Modeling to Device-Induced Platelet Defects in Mechanically Assisted Circulation

Area of Science:

• Biomedical Engineering
• Hematology
• Fluid Dynamics

Background:

• Mechanically assisted circulation devices can cause thrombotic and bleeding events.
• These complications are often linked to platelet dysfunction induced by the devices.

Purpose of the Study:

• To correlate computational fluid dynamics (CFD) modeling of blood pumps with device-induced platelet defects.
• To establish a predictive model for platelet damage in mechanical circulatory support systems.

Main Methods:

• Circulating fresh human blood through four different blood pumps under various conditions.
• Analyzing blood samples for platelet activation (GP IIb/IIIa) and receptor shedding (GPIbα, GPVI).
• Performing CFD modeling to characterize blood flow and deriving numerical indices of platelet defects using power-law models.

Main Results:

• A shear stress threshold of 75 Pa was identified as a key factor, with lower stress having limited contribution to platelet damage.
• CFD-derived platelet defect indices, excluding shear stress <75 Pa, showed excellent correlation with experimental measurements.
• The power-law model demonstrated effectiveness for quantitative comparisons, despite not perfectly reproducing experimental data.

Conclusions:

• CFD modeling, particularly using power-law models with a shear stress threshold, can effectively predict device-induced platelet defects.
• This approach offers a valuable tool for the quantitative assessment and comparison of blood pumps regarding hemocompatibility.
• Understanding shear stress thresholds is crucial for designing safer mechanical circulatory support devices.