Virtual Evaluation on Coronary Artery Bypass Graft Surgery Techniques

Abstract: Coronary artery bypass graft surgery (CABG) with vein grafts is the mainstay of multivessel surgical revascularization in coronary artery disease due to limited availability of arterial grafts. In multi-target revascularization, cardiothoracic surgeons are often faced with choices of different revascularization geometries and sizes for saphenous venous grafts (SVG). Decisions regarding preferable vein graft configurations rely on retrospective studies, surgeons’ intuition, training, and experience, as well as the available saphenous veins. Prior studies comparing the efficacy and superiority of revascularization techniques between single and sequential grafts show mixed results.   

It is well known that hemodynamics, wall mechanics, and geometry play a critical role in the long-term adaptation of vein grafts. Specifically, wall shear stress (WSS) has been identified as an important mechanical stimulus for atherosclerosis progression and vein graft remodeling. Animal studies have shown strong correlation between low wall shear stress and intimal hyperplasia in vein grafts.  Image-based cardiovascular simulations using computational fluid dynamics (CFD) techniques provide a non-invasive means to quantify mechanical stimuli on vein grafts in patient-specific geometries. In this study, we performed simulations on patient-specific cardiovascular CABG models to quantitatively compare several revascularization geometries commonly used in clinical practice, while systematically varying the size of the implanted vein grafts.   

Collaborators: Abhay Ramanchandra (Yale),  Jack Boyd (Stanford), Andrew Kahn (UCSD), Alison Marsden (Stanford)  

Funding Sources: National Institute of Health (NIH), National Science Foundation (NSF).