Experimental fluid dynamics of transventricular apical aortic cannulation

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Fluid Dynamics

Background:

• Transventricular apical aortic cannulation is an alternative to standard aortic cannulation for cardiopulmonary bypass.
• Understanding the hydrodynamic characteristics of apical cannulation is crucial for optimizing its clinical application.

Purpose of the Study:

• To analyze and compare the flow patterns generated by transventricular apical aortic cannulation versus standard aortic cannulation.
• To evaluate the hydrodynamic efficiency and potential for shear stress induction of different apical cannulas.

Main Methods:

• Particle-image velocimetry was employed in a glass aortic model to visualize flow dynamics.
• Simulations included a 7-mm Sarns Soft-Flow cannula and a novel 7-mm apical aortic cannula, compared against standard aortic cannulation.
• Analysis focused on flow velocity, streamlines, and the distribution of the strain rate tensor magnitude.

Main Results:

• Apical cannulation demonstrated a significantly steadier and more organized flow profile than standard aortic cannulation.
• The magnitude of the strain rate tensor, indicative of shear stress, decreased within centimeters of the apical cannula exit.
• The newly developed apical cannula exhibited favorable flow characteristics.

Conclusions:

• Transventricular apical aortic cannulation provides a more organized flow pattern, potentially reducing risks associated with turbulent flow.
• The observed reduction in shear stress near the apical cannula suggests a potentially safer profile for blood elements.
• These findings support the further investigation and potential clinical adoption of apical cannulation techniques.