Haemolysis induced by mechanical circulatory support devices: unsolved problems.

Area of Science:

• Biomedical Engineering
• Hematology

Background:

• Continuous flow blood pumps are standard ventricular assist devices.
• Increased use has led to greater problems with hemolysis.
• Shear stress on the erythrocyte membrane is the primary cause of hemolysis.

Purpose of the Study:

• To review and present findings on hemolysis in laminar and turbulent blood flow.
• To discuss models for calculating erythrocyte strength.
• To examine theoretical approaches for designing low-hemolysis blood pumps.

Main Methods:

• Summarizing existing research on hemolysis thresholds.
• Presenting hemolysis data in graphical form (curves).
• Discussing various models for erythrocyte strength calculation.

Main Results:

• Hemolysis threshold levels vary significantly based on experimental methods and calculation strategies.
• Erythrocyte damage is dependent on shear stress exposure time.
• Few studies directly test hemolysis in blood pumps, but theoretical designs exist.

Conclusions:

• Further research is needed to standardize hemolysis testing and design criteria for blood pumps.
• Understanding erythrocyte mechanics under shear stress is crucial for improving VAD safety.
• Theoretical models show promise for developing future blood pump designs with reduced hemolytic potential.