PIV Analysis of Stented Haemodynamics in the Descending Aorta

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Device Technology

Background:

• Cardiovascular diseases (CVD) are a leading cause of mortality globally.
• Aortic aneurysms, particularly in the descending aorta, are significant contributors to CVD mortality.
• The Frozen Elephant Trunk (FET) stent is a primary treatment for complex aortic aneurysms.

Purpose of the Study:

• To investigate the in-vitro hemodynamics of a stented descending aorta using a compliant phantom.
• To analyze the behavior of the Frozen Elephant Trunk (FET) stent, focusing on passive fixation.
• To identify potential risks associated with FET stent implantation in descending aorta treatments.

Main Methods:

• Manufactured a compliant silicone phantom of the descending aorta.
• Fabricated a PVC stent using a lost core casting method.
• Employed Particle Image Velocimetry (PIV) for pulsatile flow studies.

Main Results:

• Observed an apparent expansion of the stent during diastole, identified as a lateral plane collapse.
• Detected flow recirculation regions coinciding with the stent collapse.
• Attributed the collapse to a vacuum effect caused by pressure differentials (low upstream, high downstream).

Conclusions:

• The FET stent may exhibit a collapse in the lateral plane during the diastolic period.
• This collapse, driven by pressure dynamics, could introduce risks requiring further investigation.
• Findings highlight the need for continued research into FET stent biomechanics and clinical implications.