Hemodynamics of endovascular prostheses

Area of Science:

• Biomedical Engineering
• Cardiovascular Surgery
• Fluid Dynamics

Background:

• Expandable stents are used to reduce restenosis after balloon angioplasty.
• Re-endothelialization of stents is slower in bifurcated iliac arteries than in straight femoro-popliteal arteries.
• Local hemodynamics are a significant factor in atherosclerosis development.

Purpose of the Study:

• To compare and optimize stent design for aorto-iliac bifurcation stenting.
• To investigate the influence of stent protrusion on flow patterns in bifurcation branches.
• To evaluate methods for reducing hemodynamic disturbances caused by stenting.

Main Methods:

• In vitro study using an aorto-iliac bifurcation model.
• Qualitative flow visualization in the horizontal median plane.
• Quantitative Doppler ultrasonic velocimetry at various cardiac cycle points.

Main Results:

• Standard stent protrusion into a daughter branch significantly alters flow patterns.
• A novel beveled stent design demonstrated a notable reduction in flow disturbances.
• Hemodynamic impact is directly related to the extent of stent protrusion.

Conclusions:

• Stent design is critical for optimizing hemodynamics at arterial bifurcations.
• Beveled stent designs offer a promising approach to minimize flow disturbances.
• Findings provide guidance for surgeons on optimal stenting techniques at bifurcations.