Secondary flow in peripheral vascular prosthetic grafts using vector Doppler imaging

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Fluid Dynamics

Background:

• Peripheral arterial disease (PAD) treatment often involves prosthetic grafts.
• Graft re-stenosis at the distal anastomosis is a primary cause of graft failure.
• Local hemodynamics significantly influence neo-intimal hyperplasia development.

Purpose of the Study:

• To evaluate a new prosthetic graft design engineered to induce optimized spiral flow.
• To compare the secondary flow patterns generated by the novel graft versus a control device.
• To assess the impact of graft design on hemodynamics relevant to graft patency.

Main Methods:

• Utilized ultrasound flow phantoms with identical vessel mimic geometry.
• Applied constant flow rates and dual-beam vector Doppler for data acquisition.
• Generated 2-D velocity maps to analyze flow patterns distal to the graft outflow.

Main Results:

• The flow-modified graft induced a single-spiral flow pattern.
• The control graft exhibited double or triple spiral flow patterns.
• The flow-modified graft demonstrated greater in-plane maximum velocity compared to the control.

Conclusions:

• The novel graft design successfully generated an optimized single-spiral flow.
• This optimized flow may mitigate hemodynamic factors contributing to neo-intimal hyperplasia.
• The findings suggest potential for improved graft performance and reduced occlusion in PAD treatment.