Prospective Evaluation of Adventitial Histopathology in Borderline Ascending Aortic Dilatatio

This prospective study investigates microscopic changes in the outer layer (adventitia) of the ascending aorta in patients undergoing coronary artery bypass grafting (CABG) surgery. The study includes two groups of patients: (1) those with borderline ascending aortic dilatation (4.0-5.0 cm), and (2) a control group with normal aortic diameter (\<4.0 cm), all undergoing the same surgical procedure. During CABG, a small circular punch is routinely made in the ascending aorta for the proximal saphenous vein graft anastomosis. The tissue removed from this punch site is collected and used for histopathological and immunohistochemical analysis. The study aims to determine whether adventitial changes correlate with aortic size and whether these changes can help identify patients at risk for future aortic dissection or rupture. The findings may guide surgical decision-making in patients with borderline aortic enlargement.