Optimum incision geometry in side-to-side anastomosis

In coronary artery bypass grafting (CABG), the use of a saphenous vein (SV) graft to the left anterior descending (LAD) artery is prevalent. While end-to-side anastomosis (ESA) is considered standard practice, several studies have highlighted the effectiveness of side-to-side anastomosis (SSA). Optimizing the cross-sectional geometry is one of the factors influencing the success of the anastomosis. Among the possible configurations, an elliptical cross-section is the most suitable option because of its smooth perimeter and its ability to prevent stress concentration. The optimal diameter ratio for this elliptical cross-section can be determined through an optimization process. This study investigated the impact of punch geometry on the side-to-side anastomosis (SSA) at a 90-degree grafting angle, specifically examining the residual stress and strain caused by the grafting of two arteries. The analysis was conducted both without and under blood pressure at the junction and considered different ratios of elliptical punch diameters. According to the simulation results, the lowest residual stress and the lowest stress induced by blood pressure occur at the junction of the two arteries when using an elliptical punch with a larger diameter ratio in the circumferential direction of the LAD.