This ex vivo study used computational fluid dynamics to evaluate the hemodynamic effects of various degrees of stenosis in end-to-side anastomoses commonly found in coronary artery bypass grafting. Using a porcine heart model, researchers created 25 percent, 50 percent, 75 percent, 90 percent, and 100 percent stenosis configurations in both longitudinal shortening and bilateral narrowing. At 75 percent stenosis, both types of narrowing produced abnormal flow separation, low wall shear stress, and high oscillatory regions distal to the anastomosis toe—conditions associated with intimal hyperplasia and potential graft failure. Anastomotic stenosis below 50 percent demonstrated acceptable hemodynamics. The study highlights the need for further research on long-term clinical outcomes related to suboptimal anastomotic construction techniques.