Related Experiment Video
Updated: Jul 10, 2026
Evaluation of a Novel Laser-assisted Coronary Anastomotic Connector - the Trinity Clip - in a Porcine Off-pump Bypass Model
Published on: November 24, 2014
Computational study of blood flow in an aorto-coronary bypass model using single versus sequential grafting technique
1Media Division, Institute for Infocomm Research, Singapore. meena@i2r.a-star.edu.sg
Insights
Sequential bypass grafting is more effective than single grafts for blocked coronary arteries. This technique improves blood flow dynamics and may enhance long-term graft patency in complex coronary artery disease.
Area of Science:
- Cardiovascular Surgery
- Biomedical Engineering
- Hemodynamics
Background:
- Coronary artery bypass grafting (CABG) restores blood flow to the heart muscle.
- Sequential grafting is used for multiple blocked coronary arteries, but its hemodynamic advantages are not fully understood.
Purpose of the Study:
- To analyze blood flow in a 3D coronary artery bypass graft model.
- To compare hemodynamics between single and sequential bypass grafting techniques.
- To evaluate wall shear stress and its gradients in bypassed regions.
Main Methods:
- Utilized a 3D computational fluid dynamics model of the aorto-coronary bypass graft.
- Employed the finite volume technique to simulate blood flow patterns.
- Analyzed wall shear stress (WSS) and spatial gradients (WSSG) during mid-ejection and mid-diastole phases.
Main Results:
- Wall shear stress gradients (WSSG) were significantly higher with single bypass grafts.
- The study modeled occlusions in the obtuse marginal 1 (90%) and 2 (80%) branches of the left circumflex artery.
- Hemodynamic performance varied between single and sequential bypass configurations.
Conclusions:
- Sequential bypass grafting is suggested to be more efficient for multiple coronary artery occlusions.
- This technique may contribute to improved long-term graft patency.
- Understanding bypass configuration is crucial for optimal surgical outcomes.
Abstract:
Coronary artery bypass grafting (CABG) is performed to obtain myocardial reperfusion downstream from severe coronary stenoses. When a single artery is blocked the routine CABG is performed while more than one artery are blocked, say the branches of the coronary vessels are stenosed, sequential grafting technique is adopted. However even though the advantage of using sequential bypass grafting over single bypass grafts are not fully known, the hemodynamics of the surgically reconstructed coronary bed is strongly dependent on the bypass configuration. Hence an attempt is made to analyse the blood flow in a three-dimensional aorto-coronary bypass graft model (which has the proximal portion of the branches of the left circumflex artery, namely the obtuse marginals 1 and 2 to be 90% and 80% occluded) using single grafts and sequential bypass graft. The finite volume technique was employed to model the 3-D blood flow pattern to determine the distribution of wall shear stress (WSS) and their spatial gradients (WSSG) in the bypassed regions for two specific instances of the cardiac cycle namely, t=0.15 s the mid-ejection phase and t=0.57 s the mid-diastole phase Results confirm that WSSG distribution is much higher while using single bypass grafts. Hence it is suggested that when two or more branches of the coronary vessels are occluded, sequential bypass grafting technique would be more efficient thereby contributing to the long-term graft patency.
