Related Experiment Video
Updated: May 6, 2026
11:00
Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section
Published on: July 19, 2016
10.3K
Comparison between experimentally measured flow patterns for straight and helical type graft.
Sandor I Bernad1, Alin Bosioc, Elena S Bernad
1Romanian Academy - Timisoara Branch, Centre for Fundamental and Advanced Technical Research, Bd. Mihai Viteazul 24, RO-300223, Timisoara, Romania.
Bio-Medical Materials and Engineering
|November 12, 2013
Summary
Arterial bypass graft success is limited by intimal hyperplasia. Helical grafts improve blood flow mixing at the anastomosis, potentially reducing this complication compared to straight grafts.
Area of Science:
- Biomedical Engineering
- Fluid Dynamics
- Cardiovascular Surgery
Background:
- Long-term success of arterial bypass surgery is hindered by intimal hyperplasia at the graft-artery anastomosis.
- Understanding hemodynamics at the anastomosis is crucial for improving graft patency.
Purpose of the Study:
- To determine 3D flow structures at the proximal anastomosis under pulsatile flow.
- To investigate the impact of anastomosis angle and flow division on flow patterns.
- To compare flow dynamics between straight and helical arterial grafts.
Main Methods:
- Experimental models using glass tubing (8 mm internal diameter) in straight and helical configurations.
- Analysis of three-dimensional flow structures and secondary flows.
- Measurement of axial velocity patterns under pulsatile flow conditions.
Main Results:
- A strong recirculation zone was observed at the anastomosis, directing flow into the host artery.
- Weak counter-rotating vortices were present in the proximal host tube, minimally dependent on Reynolds number (Re).
- Helical grafts exhibited significantly stronger secondary flows and enhanced mixing compared to straight grafts.
Conclusions:
- Helical graft configuration promotes vortex-induced mixing, improving blood flow downstream of the anastomosis.
- These findings suggest helical grafts may offer advantages in reducing intimal hyperplasia progression.
- Optimizing anastomosis design is key to enhancing long-term arterial bypass graft survival.
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