Understanding coronary bypass grafts from mechanical constitutive models to machine learning: A review

Cardiovascular diseases remain the leading cause of mortality worldwide, primarily resulting from the narrowing or blockage of blood vessels. Coronary artery bypass grafting (CABG) is a common surgical intervention that restores blood flow to the heart by using alternative vessels as grafts. Although saphenous vein grafts (SVGs) are frequently utilized in these procedures, they are prone to re-occlusion within 10 years, largely due to intimal hyperplasia and the development of atherosclerosis. In contrast, grafts using the mammary artery (MA) and radial artery demonstrate significantly better long-term patency and are less susceptible to occlusion. Mechanical characterization, numerical simulation, and artificial intelligence models are becoming essential to enhance surgical planning and outcomes. These digital tools provide predictive insights on intimal thickening and restenosis from medical images, thereby assisting surgeons in making well-informed decisions. This review explores the various types of grafts and the latest research in this field, focusing on graft materials, their mechanical properties, computational techniques, artificial intelligence models related to bypass surgery, and the resulting clinical implications. By highlighting the limitations of current methodologies, this review underscores the critical need for the research community to develop more advanced tools to optimize grafting outcomes.